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Specialized Solutions, Inc.
Copyright© 2004 by Specialized Solutions, Inc. All rights reserved. Printed in the United States of America. No part of this book may be used or reproduced in any form or by any means, or stored in a database or retrieval system, without prior written permission of the publisher, except in the case of brief quotations embodied in critical articles and reviews. Making copies of any part of this book for any purpose is a violation of United States copyright laws. For further information, please write to: Publisher, c/o Specialized Solutions, Inc., 338 East Tarpon Street, Tarpon Springs, FL 34689. ISBN: 1-893596-44-3 This book is sold as is, without warranty of any kind, either expressed or implied, respecting the contents of this book, including but not limited to implied warranties for the books quality, performance, merchantability or fitness for any particular purpose. Neither Specialized Solutions, Inc., nor its authorized distributors, shall be liable to the purchaser or any other person or entity with respect to any liability, loss or damage caused, or alleged to be caused, directly or indirectly by this book. Furthermore, any mention or reference to any products does not constitute an endorsement by Specialized Solutions, Inc. Publisher: Specialized Solutions, Inc.
Contributing Writers: Bill Ferguson Richard Harrison Garrett Smiley Editor: Bill Ferguson
Trademark Acknowledgments Brands and product names cited in this manual are trademarks or registered trademarks held by their respective companies. Any use of a term in this book should not be regarded as affecting the validity of any trademark or service mark. Suggestions/Comments Please forward all comments or suggestions to: Specialized Solutions, Inc. 338 East Tarpon St. Tarpon Springs, FL 34689
Table of Contents
Table of Contents
INTRODUCTION...............................................................................................................1 COMPTIA TEST OBJECTIVES FOR NETWORK+ .............................................................2005 STUDY PLAN STRATEGIES ..................................................................................................9 YOUR VIDEO INSTRUCTOR .................................................................................................9 HOW TO TAKE THE TEST ..................................................................................................10 Who may take the test? ...............................................................................................10 How to Prepare to Ensure Exam Success...................................................................10 ABOUT THIS COURSE .......................................................................................................13 CHAPTER 1 – NETWORKING FUNDAMENTALS ..................................................17 INTRODUCTION TO NETWORKING ....................................................................................17 Benefits of Networking Computers .............................................................................17 Local Area Networks (LAN) and Wide Area Networks (WAN) .................................18 The Client/Server Relationship ...................................................................................19 Client/Server Networking............................................................................................19 Peer-to-Peer Networking ............................................................................................20 BASIC NETWORK STRUCTURE (TOPOLOGY).....................................................................21 Bus Topology ..............................................................................................................21 Star Topology..............................................................................................................22 Ring Topology.............................................................................................................22 SPECIAL TOPOLOGIES ......................................................................................................23 Hybrid Topologies ......................................................................................................23 Mesh Topology............................................................................................................23 Wireless Topology.......................................................................................................24 NETWORK ACCESS ...........................................................................................................26 Token Passing .............................................................................................................26 Ethernet.......................................................................................................................26 Fast Ethernet...............................................................................................................27 HUBS AND CONCENTRATORS ...........................................................................................28 Passive Hubs...............................................................................................................28 Active Hubs .................................................................................................................29 Hub-Based Networks ..................................................................................................29 SUMMARY ........................................................................................................................30 KEYWORDS EXERCISE .................................................................................................31 REVIEW QUESTIONS - CHAPTER 1 ....................................................................................33 CHAPTER 2 - NETWORK OPERATING SYSTEMS (NOS) ....................................35 WHAT IS AN OPERATING SYSTEM? ..................................................................................35 Preemptive vs. Non-preemptive Multitasking .............................................................36 WHAT IS A NETWORK OPERATING SYSTEM (NOS)? ........................................................37 Peer-to-Peer LANs......................................................................................................37 Server/Client Software ................................................................................................39 NOS PACKAGES...............................................................................................................42 Specialized Solutions, Inc. i
Network + Training & Test Preparation Guide Novell NetWare .......................................................................................................... 42 Microsoft Windows NT Network Operating System................................................... 45 Windows NT Minimum Requirements ...........................Error! Bookmark not defined. UNIX Operating Systems............................................................................................ 47 Banyan VINES (Virtual Integrated Network Service)................................................ 48 SUMMARY ....................................................................................................................... 50 KEYWORDS EXERCISE ................................................................................................. 51 REVIEW QUESTIONS ........................................................................................................ 52 CHAPTER 3- THE OSI MODEL AND COMMUNICATION STANDARDS.......... 55 THE SEVEN LAYERS OF NETWORK COMMUNICATION ..................................................... 55 SEVEN LAYERS OF THE OSI MODEL ................................................................................ 56 Application Layer ....................................................................................................... 56 Presentation Layer ..................................................................................................... 57 Session Layer.............................................................................................................. 57 Transport Layer.......................................................................................................... 57 Network Layer ............................................................................................................ 58 Data Link Layer.......................................................................................................... 58 Logical Link Control (LLC) ....................................................................................... 59 Media Access Control (MAC) .................................................................................... 59 Physical Layer............................................................................................................ 60 PROTOCOL STACKS ......................................................................................................... 62 Communication Between Peer Layers ....................................................................... 62 OSI AND THE REAL WORLD ............................................................................................ 64 DEVICES AND THE OSI MODEL ....................................................................................... 66 Repeaters .................................................................................................................... 66 Bridges........................................................................................................................ 66 Routers........................................................................................................................ 66 Brouters ...................................................................................................................... 67 Gateways .................................................................................................................... 67 IEEE 802 STANDARDS .................................................................................................... 68 NETWORK DRIVERS AND THE OSI MODEL ...................................................................... 70 NDIS (Network Driver Interface Specification)......................................................... 70 ODI (Open Data Link Interface) ................................................................................ 70 PROTOCOLS AND OSI ...................................................................................................... 70 Protocol Binding ........................................................................................................ 71 Connection-Oriented vs. Connectionless ................................................................... 71 Routable vs. Non-Routable Protocols ........................................................................ 71 Networking Protocols and Stacks............................................................................... 72 AppleTalk.................................................................................................................... 73 DECnet ....................................................................................................................... 73 IPX/ SPX..................................................................................................................... 73 SMB (Server Message Block) ..................................................................................... 74 SNA (Systems Network Architecture) ......................................................................... 74 TCP (Transmission Control Protocol) ....................................................................... 74 IP (Internet Protocol)................................................................................................. 74 UDP (User Datagram Protocol)................................................................................ 74 FTP (File Transfer Protocol) ..................................................................................... 74 ii Specialized Solutions, Inc.
Table of Contents Telnet...........................................................................................................................75 NFS (Network File System).........................................................................................75 SMTP (Simple Mail Transfer Protocol)......................................................................75 RIP (Routing Information Protocol)...........................................................................75 NTP (Network Time Protocol) ....................................................................................75 OSPF (Open Shortest Path First) ...............................................................................75 ARP (Address Resolution Protocol)............................................................................75 X.25 .............................................................................................................................76 XNS (Xerox Network System)......................................................................................76 Non-Routable Protocols..............................................................................................76 DLC (Data Link Control)............................................................................................76 LAT (Local Area Transport) .......................................................................................76 NetBEUI (NetBIOS Extended User Interface)............................................................77 Other Protocols...........................................................................................................78 SLIP (Serial Line Internet Protocol)...........................................................................78 PPP (Point-to-Point Protocol) ...................................................................................78 PPTP (Point-to-Point Tunneling Protocol) ................................................................78 SNMP (Simple Network Management Protocol) ........................................................78 ISO/OSI Standard .......................................................................................................78 ICMP (Internet Control Message Protocol) ...............................................................78 DNS (Domain Name System) ......................................................................................78 XDR (External Data Representation) .........................................................................78 RPC (Remote Procedure Call)....................................................................................78 SUMMARY ........................................................................................................................80 KEYWORDS EXERCISE .................................................................................................81 REVIEW QUESTIONS – CHAPTER 3 ...................................................................................82 CHAPTER 4 - HARDWARE MEDIA AND PERIPHERALS.....................................85 NETWORK CABLING .........................................................................................................85 Coaxial Cable .............................................................................................................85 Coaxial Connectors ....................................................................................................86 Twisted-Pair Cable .....................................................................................................88 Fiber-Optic Cable.......................................................................................................91 IBM Cabling................................................................................................................91 Summary of Cabling ...................................................................................................93 CABLING TERMS ..............................................................................................................94 AWG (American Wire Gauge) ....................................................................................94 Bandwidth ...................................................................................................................94 Plenum Grade Cabling ...............................................................................................94 Selecting Cables..........................................................................................................95 NETWORK INTERFACE CARDS (NICS)..............................................................................97 Preparing the Data .....................................................................................................97 Signals and Clocking ..................................................................................................97 Network Addressing/MAC Address.............................................................................98 DMA (Direct Memory Channel) .................................................................................98 Controlling the Data Flow..........................................................................................98 Configurable Options..................................................................................................98 Wireless NICs............................................................................................................100 Specialized Solutions, Inc. iii
Network + Training & Test Preparation Guide Fiber-Optic NICs...................................................................................................... 100 DATA BUS ARCHITECTURE ............................................................................................ 101 Standard Bus Types .................................................................................................. 101 Laptops ..................................................................................................................... 101 NETWORK PERFORMANCE ............................................................................................. 102 WIRELESS NETWORKS ................................................................................................... 103 Why Wireless? .......................................................................................................... 103 Wireless Transmission Methods............................................................................... 104 Radio Transmission.................................................................................................. 105 Satellite Station Networking..................................................................................... 106 SUMMARY ..................................................................................................................... 108 KEYWORDS EXERCISE ............................................................................................... 109 REVIEW QUESTIONS CHAPTER 4.................................................................................... 112 CHAPTER 5 – NETWORK PROTOCOLS & STANDARDS .................................. 115 ACCESS METHODS......................................................................................................... 116 CSMA/CD (Carrier-Sense Multiple Access with Collision Detection) .................... 116 CSMA/CA (Carrier-Sense Multiple Access with Collision Avoidance) ................... 117 Token Passing........................................................................................................... 117 Demand Priority....................................................................................................... 117 NETWORK COMMUNICATIONS (FRAMES AND PACKETS) ............................................... 119 Packet Structure ....................................................................................................... 119 Packet Components .................................................................................................. 120 NETWORK STANDARDS ................................................................................................. 122 Logical Link Control (802.2).................................................................................... 122 Ethernet (802.3)........................................................................................................ 122 AppleTalk.................................................................................................................. 129 ARCNet ( Attached Resource Computer Network)................................................... 131 SUMMARY ..................................................................................................................... 133 KEYWORDS EXERCISE ............................................................................................... 134 REVIEW QUESTIONS CHAPTER 5.................................................................................... 136 CHAPTER 6 – NETWORK DESIGN.......................................................................... 139 STARTING A NETWORK PROJECT ................................................................................... 139 The Customer ........................................................................................................... 139 The Network Goals................................................................................................... 140 DETERMINE NETWORK TYPE ......................................................................................... 142 When to Choose Peer-to-Peer.................................................................................. 142 When to Choose Client/Server ................................................................................. 143 Making the Choice.................................................................................................... 144 Public and Private networks .................................................................................... 144 DESIGN THE NETWORK.................................................................................................. 150 Media Selection ........................................................................................................ 151 Environmental Concerns.......................................................................................... 152 NOS Selection........................................................................................................... 152 Protocol Selection .................................................................................................... 152 PUTTING IT ALL TOGETHER ............................................................................................ 154 Cable to Computer ................................................................................................... 154 iv Specialized Solutions, Inc.
........................................................................................................................................164 CHAPTER 7 ..................161 HCL and Windows 2000 ..........................................................................................................................................................................................................................................................................................................................................................................183 KEYWORDS EXERCISE .............................................................................166 Bridges ...............................................................174 MODEMS ...................173 Advanced WAN Environments ............165 EXPANDING A LAN WITH HUBS.............Table of Contents Cable to Hub ...................................................................................................................................................161 Minimum Requirements ..............................................................................................................................................................................................EXPANDING A NETWORK ........................................................................189 INTRODUCTION TO TCP/IP............................................................................166 Routers .............184 REVIEW QUESTIONS CHAPTER 7 ...........................................................................................................................................................................................189 RFC (Request For Comments)...........189 TCP/IP PROTOCOLS ...............................................................................................................192 The Top Five TCP/IP Protocols .169 Analog Connectivity........................................................................................................................................................................167 Gateway ............................................................................176 REMOTE ACCESS COMPUTING (RAS) ...........................................................166 Repeaters..................................................................................162 REVIEW QUESTIONS CHAPTER 6 ................................159 Computer Compatibility..............................................................160 RESOLVING COMPATIBILITY PROBLEMS ..157 Adapter Card Compatibility ..............................................................................................................................................................................................157 Media Compatibility ..................................................................................................182 Troubleshooting a RAS setup...................172 VLAN.......................................................................................................................................................................................................................................................................................................................................................178 Connecting Two Computers..179 Installing and Configuring RAS..............................................................................................................................194 NAMING SYSTEMS .........197 DNS ................................................................................................................................................................................................................160 Hard Work ..............................................................................................................................................................................................160 Standards ..........168 Carriers.................................................................................................................................................................................................................. Inc...........................192 Other TCP/IP Protocols ...................................................................170 Circuit-switched Networks................................................................................154 Network Adapter Cards ..............................................182 Limitations of RAS .............................................197 Specialized Solutions.169 Digital Connectivity .................. v ..................168 WAN Overview..............................................165 WHEN A LAN IS TOO SMALL .......................................................................................................................................................................................................................................159 PREVENTING COMPATIBILITY PROBLEMS ....................................................186 CHAPTER 8 – TCP/IP ESSENTIALS .......................................155 NETWORK AND HARDWARE COMPATIBILITY .........................................................................................178 RAS Protocols ..................167 CONNECTION SERVICES .................................................................................172 Packet Switching Networks.........................................................................................................
...................................................................................................................................... 203 IPv6 (IP Next Generation) ............................................................... 222 Communities..... 198 HOSTS file....................................................................................................................................................................................... 202 IP Addresses .................... 207 How to Subdivide a Network ........................................................... 225 RARP...................................................................................................................... 225 ARP ........................... 222 EVENT VIEWER .......................... 223 NETSTAT ............................................................................................................................................................................................................................................................................................................................................................................................................... 199 LMHOSTS file ........................................................... 200 TCP/IP ADDRESSING....................................... 199 DHCP ................................................................................................................................................................................. 225 IPCONFIG/WINIPCFG .................................................................................................................................................................................. 221 Agent Software ..................................... 219 CHAPTER 9 – TCP/IP UTILITIES................................................................................................... 203 Class D and Class E Addresses. 223 ROUTE................................................................................................................................................................... 199 BOOTP .............. 225 PING........................................................................................................................................................................................ 209 TCP/IP CONFIGURATION CONCEPTS ....................................................................... 229 USER AND SHARE LEVEL ........................................................................................................................................................................................................................................... 200 IP Proxy Servers... 223 TRACERT.............................................................................. 200 ICS ..................................... 200 NAT...................................................................................................................................... 229 vi Specialized Solutions...................................................................................... 228 CHAPTER 10 – NETWORK SECURITY .......................................................... 202 IPv4 .......................... 221 Management Software......... 225 NSLOOKUP................................................................................... Inc......................... 203 Class A Addresses ................................................................ 217 REVIEW QUESTIONS CHAPTER 8.......... 222 VALIDATION TOOLS ..... ............... 198 NETBIOS ....................... 225 KEYWORDS EXERCISE .................SNMP .......................................... 227 REVIEW QUESTIONS CHAPTER 9....................................................................................................................................................................................... 215 KEYWORDS EXERCISE ............................... 223 NBTSTAT .......... 205 SUBNETTING .................................................................................................................................................................................................................................................................. 225 IFCONFIG........................................................................................................................Network + Training & Test Preparation Guide WINS................................................................................................................................................................ 199 IP Gateway ................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 199 NETWORK CONNECTION UTILITIES ............................................... 203 Class B Addresses ...................................................................................................................................... 223 TROUBLESHOOTING TOOLS ............... 203 Class C Addresses ....... 221 NETWORK MANAGERS ................................................................................................................................................................................
..........................................................................273 SUBNET MASKING .......................................................257 Misbehaving Protocols .........................................................................................................................................................................................255 TROUBLESHOOTING SCENARIOS .......................................... Differential............................................................................................................................................................................................................................................................................................................................................X STANDARDS.......................................................................................................250 Hardware Networking Tools............234 Fault Tolerance and Power ..................................................243 CHAPTER 11 – TROUBLESHOOTING A NETWORK ......................................................................................267 COAXIAL CABLE TYPES ...................232 Blocking Port Numbers.........................................................264 APPENDIX A – TECH SUMMARY .........................................................................................................................................................................................................................................................................251 MAINTAINING AND TROUBLESHOOTING NETWORKS ...........................................................................................................................................................................................................................................................................................................234 Full..................................................................................................237 Encryption........................................................................................................................................................................................................................................245 NETWORKING AND TROUBLESHOOTING TOOLS .....................................267 ETHERNET CABLING .........................................................................................232 Backup Options.................................................................................................................257 Cable Problems..........................................................271 OSI MODEL ............................................263 REVIEW QUESTIONS CHAPTER 11 ...........................Table of Contents User-level Security........................268 UTP CABLE CATEGORIES ....269 IEEE 802......................................................................274 TCP/IP PORTS ...............................................................................................................................................................................260 Performance............................233 Backup Software ...................................................................267 5-4-3 RULE ........................................................................................................230 SECURITY TECHNIQUES .......................................................................................................250 Hardware Troubleshooting Tools.....................................260 KEYWORDS EXERCISE ................................ vii .................242 REVIEW QUESTIONS CHAPTER 10 .............................269 IBM CABLE TYPES (TOKEN RING) .................... and Incremental Backups .....275 TCP/IP UTILITIES .......................................239 KEYWORDS EXERCISE ..............................................................................................................................................................................................................................................................................................................270 IRQ ASSIGNMENTS ............................................................................................. Inc..............275 Specialized Solutions....................................................................236 PASSWORD PRACTICES AND PROCEDURES .......................................................234 Volumes........................................................................................................................234 Fault Tolerance and RAID.......................................264 CONCLUSION ..................238 Disaster Recovery ...........229 Share-level Security ..........................................................................................................................................................................................................................232 Backing up Data .............................232 Firewalls .....................................245 BASIC TROUBLESHOOTING...........................239 Viruses.260 Name Resolution ...........................................................................................................................................259 NIC Indicator Lights .........................................
.................................................................................................................................... 278 APPENDIX B – USEFUL WEB SITES ................................. 281 NOVELL ...................................................................................................................................................... 303 REVIEW QUESTIONS CHAPTER 2................................................................................................................................................................................................................................................................................................................................................. 309 REVIEW QUESTIONS CHAPTER 5........................................... 306 REVIEW QUESTIONS CHAPTER 4..................................................................................................... 283 EIA ................................................................................................................................... 318 REVIEW QUESTIONS CHAPTER 9.................................................................................................................................... 278 TROUBLESHOOTING TOOLS .................... ERROR! BOOKMARK NOT DEFINED.................................................................... 281 COMPUSERVE ................. 316 REVIEW QUESTIONS CHAPTER 8........... 284 SAG ......................................................... OTHER HELPFUL SITES ................... 284 ISO........ 285 TO REGISTER FOR THE NETWORK+ EXAMS ..........................................................................................Network + Training & Test Preparation Guide TOPOLOGY REVIEW ........................................................................................................ 311 REVIEW QUESTIONS CHAPTER 6................................................................................................................ 281 APPENDIX C – NETWORK STANDARDS ORGANIZATIONS ........................................... 315 REVIEW QUESTIONS CHAPTER 7.............................. 304 REVIEW QUESTIONS CHAPTER 3...... 303 REVIEW QUESTIONS CHAPTER 1........................ 320 REVIEW QUESTIONS CHAPTER 11............ 285 APPENDIX E – GLOSSARY................ 321 INDEX ................................................................................................... 287 APPENDIX F – CHAPTER REVIEW QUESTIONS AND ANSWERS ................................................ 281 MICROSOFT: ............ ......................................................... 319 REVIEW QUESTIONS CHAPTER 10........................................................................................................................ 284 APPENDIX D – HOW TO REGISTER FOR THE EXAM................................................................ 283 IEEE .......... 276 TRANSMISSION MEDIA .................................................................... 283 ANSI...................................................................................................................................... Inc........................................................................................................................................................................................................ 323 viii Specialized Solutions............................................................................................................................................................................................................................... 283 CCITT ..................................................................
Specialized Solutions. please visit us at: www. We are committed to always be on the leading edge of new computer environment training products.specializedsolutions. Inc. is dedicated to providing the computer professional the highest level of self-study training and certification materials the industry has to offer. Inc.com Specialized Solutions.About Specialized Solutions About Specialized Solutions Welcome to Specialized Solutions. We strive to provide training programs that far exceed the expectations of our customers. Inc. We will always provide a quality product to customers at a price that is within reach of most computer professionals. Inc. course offerings. We thank you for choosing our company as your resource for Information Technology SelfStudy Training. Our highly skilled staff of computer and educational professionals are dedicated to delivering high quality.'s Network+ training and certification course. cost-effective programs that are customized to suit your needs. ix . One hundred percent customer satisfaction and unmatched customer service is always our commitment to the computer professional. To see other Specialized Solutions.
Network + Training & Test Preparation Guide x Specialized Solutions. Inc. .
our success is directly tied to the success our students have with our training programs.Introduction Introduction This Training Guide is designed to meet all of the Network+ exam objectives. We are here to help with all of your training and certification needs! Specialized Solutions. We have carefully prepared this multi-media training material to provide you with the needed information in a logical. Network+ video training series. Computer Graphics Experts. and Digital Video Studio Professionals. as a stand-alone textbook. We hope you enjoy your Network+ training program. It can be used in conjunction with the Specialized Solutions. at Specialized Solutions. Our staff consists of Microsoft Certified Professionals. easy to follow format. Technical Editors. or as a textbook in a classroom environment. Technical Writers. 1 . Inc. Inc. Remember.
" "This examination includes blueprint weighting.0 Network Implementation 4." The objectives are weighted in the following manner: NETWORK+ CERTIFICATION DOMAIN AREAS 1. Example concepts are included to clarify the test objectives and should not be construed as a comprehensive listing of the content of the examination. Inc.0 Network Support Total % OF EXAMINATION 20% 20% 25% 35% 100% 2 Specialized Solutions.0 Media & Topologies 2. .Network + Training & Test Preparation Guide CompTIA Test Objectives for Network+ CompTIA is an acronym for Computing Technology Industry Association "The skills and knowledge measured by this examination are derived from industry-wide job task analysis and validated through an industry wide survey. test objectives and example content.0 Protocols & Standards 3. The results of this survey were used in weighing the domains and ensuring that the weighting is representative of the relative importance of the content.
6 Identify the purposes. 1000BASE-CX. 5.5 Recognize the following media types and describe their uses: • Category 3. 802.2 (Logical Link Control).5 (token ring). 3 .2 Specify the main features of 802. and cable type) of the following cable standards: • 10BASE-T and 10BASE-FL • 100BASE-TX and 100BASE-FX • 1000BASE-T.1 Recognize the following logical or physical network topologies given a diagram. 1000BASE-SX and 1000BASE-LX • 10 GBASE-SR. 802. schematic or description: • Star • Bus • Mesh • Ring 1.3 (Ethernet). 10 GBASE-LR and 10 GBASE-ER 1. topology.Introduction The following is a further breakdown of the specific areas covered on the Network+ exam: Domain 1. and 6 • UTP (Unshielded Twisted Pair) • STP (Shielded Twisted Pair) • Coaxial cable • SMF (Single Mode Fiber) optic cable • MMF (Multimode Fiber) optic cable 1. length.Media and Topologies – 20% 1. 5e.0 . Inc. 802.3 Specify the characteristics (For example: speed.11 (wireless). features and functions of the following network components: • Hubs • Switches • Bridges • Routers • Gateways • CSU / DSU (Channel Service Unit / Data Service Unit) Specialized Solutions.4 Recognize the following media connectors and describe their uses: • RJ-11 (Registered Jack) • RJ-45 (Registered Jack) • F-Type • ST (Straight Tip) • SC (Subscriber Connector or Standard Connector) • IEEE 1394 (FireWire) • Fiber LC (Local Connector) • MT-RJ (Mechanical Transfer Registered Jack) • USB (Universal Serial Bus) 1. and FDDI (Fiber Distributed Data Interface) networking technologies. including: • Speed • Access method (CSMA / CA (Carrier Sense Multiple Access/Collision Avoidance) and CSMA / CD (Carrier Sense Multiple Access / Collision Detection)) • Topology • Media 1.
2. Inc. 2.0 – Protocols and Standards – 20% 2. 2.1 Identify a MAC (Media Access Control) address and its parts. frequency. transmission type and topology) of the following wireless technologies: • 802. .4 Differentiate between the following network protocols in terms of routing. IPv6) and the required setting for connections across the Internet. Domain 2. 2.8 Identify the differences between private and public network addressing schemes. 2. 2.11x (Direct sequence spread spectrum) • Infrared • Bluetooth 1.Network + Training & Test Preparation Guide • NICs (Network Interface Card) • ISDN (Integrated Services Digital Network) adapters • WAPs (Wireless Access Point) • Modems • Transceivers (media converters) • Firewalls 1.10 Define the purpose. antenna type and environmental factors). B and C). interoperability and naming conventions: • IPX / SPX (Internetwork Packet Exchange / Sequence Packet Exchange) • NetBEUI (Network Basic Input / Output System Extended User Interface) • AppleTalk / AppleTalk over IP (Internet Protocol) • TCP / IP (Transmission Control Protocol / Internet Protocol) 2.7 Specify the general characteristics (For example: carrier speed.7 Identify the purpose of subnetting.3 Identify the OSI (Open Systems Interconnect) layers at which the following network components operate: • Hubs • Switches • Bridges • Routers • NICs (Network Interface Card) • WAPs (Wireless Access Point) 2.6 Identify classful IP (Internet Protocol) ranges and their subnet masks (For example: Class A.9 Identify and differentiate between the following IP (Internet Protocol) addressing methods: • Static • Dynamic • Self-assigned (APIPA (Automatic Private Internet Protocol Addressing)) 2. addressing schemes.5 Identify the components and structure of IP (Internet Protocol) addresses (IPv4.2 Identify the seven layers of the OSI (Open Systems Interconnect) model and their functions.11 (Frequency hopping spread spectrum) • 802. function and use of the following protocols used in the TCP / IP (Transmission Control Protocol / Internet Protocol) suite: • TCP (Transmission Control Protocol) • UDP (User Datagram Protocol) 4 Specialized Solutions.8 Identify factors which affect the range and speed of wireless service (For example: interference.
14 Identify the basic characteristics (For example: speed. WINS (Windows Internet Name Service).Introduction • FTP (File Transfer Protocol) • SFTP (Secure File Transfer Protocol) • TFTP (Trivial File Transfer Protocol) • SMTP (Simple Mail Transfer Protocol) • HTTP (Hypertext Transfer Protocol) • HTTPS (Hypertext Transfer Protocol Secure) • POP3 / IMAP4 (Post Office Protocol version 3 / Internet Message Access Protocol version 4) • Telnet • SSH (Secure Shell) • ICMP (Internet Control Message Protocol) • ARP / RARP (Address Resolution Protocol / Reverse Address Resolution Protocol) • NTP (Network Time Protocol) • NNTP (Network News Transport Protocol) • SCP (Secure Copy Protocol) • LDAP (Lightweight Directory Access Protocol) • IGMP (Internet Group Multicast Protocol) • LPR (Line Printer Remote) 2.12 Identify the well-known ports associated with the following commonly used services and protocols: • 20 FTP (File Transfer Protocol) • 21 FTP (File Transfer Protocol) • 22 SSH (Secure Shell) • 23 Telnet • 25 SMTP (Simple Mail Transfer Protocol) • 53 DNS (Domain Name Service) • 69 TFTP (Trivial File Transfer Protocol) • 80 HTTP (Hypertext Transfer Protocol) • 110 POP3 (Post Office Protocol version 3) • 119 NNTP (Network News Transport Protocol) • 123 NTP (Network Time Protocol) • 143 IMAP4 (Internet Message Access Protocol version 4) • 443 HTTPS (Hypertext Transfer Protocol Secure) 2.15 Identify the basic characteristics of the following internet access technologies: • xDSL (Digital Subscriber Line) • Broadband Cable (Cable modem) • POTS / PSTN (Plain Old Telephone Service / Public Switched Telephone Network) • Satellite • Wireless Specialized Solutions.11 Define the function of TCP / UDP (Transmission Control Protocol / User Datagram Protocol) ports. LPD (Line Printer Daemon) and Samba). Zeroconf (Zero configuration). AFP (Apple File Protocol). SNMP (Simple Network Management Protocol). 2.13 Identify the purpose of network services and protocols (For example: DNS (Domain Name Service). ICS (Internet Connection Sharing). Inc. capacity and media) of the following WAN (Wide Area Networks) technologies: • Packet switching • Circuit switching • ISDN (Integrated Services Digital Network) • FDDI (Fiber Distributed Data Interface) • T1 (T Carrier level 1) / E1 / J1 • T3 (T Carrier level 3) / E3 / J3 • OCx (Optical Carrier) • X.25 2. NAT (Network Address Translation). NFS (Network File System). SMB (Server Message Block). 2. 5 .
RADIUS (Remote Authentication Dial-In User Service). application support and security) of the following server operating systems to access network resources: • UNIX / Linux / Mac OS X Server • Netware • Windows • Appleshare IP (Internet Protocol) 3.9 Identify the main characteristics and purpose of extranets and intranets. interoperability. Domain 3. 3.1x 2.7 Given a connectivity scenario. MS-CHAP (Microsoft Challenge Handshake Authentication Protocol). an authentication scheme. authentication and encryption). network protocols and peer and server services).2 Identify the basic capabilities needed for client workstations to connect to and use network resources (For example: media. benefits and characteristics of using a proxy service. file and print services. .6 Identify the purpose.8 Identify the main characteristics of VLANs (Virtual Local Area Networks). Includes connection to the following servers: • UNIX / Linux / MAC OS X Server • Netware • Windows • Appleshare IP (Internet Protocol) 3. determine the impact on network functionality of a particular security implementation (For example: port blocking / filtering. 3.Network + Training & Test Preparation Guide 2.5 Identify the purpose.4 Given a remote connectivity scenario comprised of a protocol.1 Identify the basic capabilities (For example: client support. authentication. punch down tool or tone generator).17 Identify the following security protocols and describe their purpose and function: • IPSec (Internet Protocol Security) • L2TP (Layer 2 Tunneling Protocol) • SSL (Secure Sockets Layer) • WEP (Wired Equivalent Privacy) Continued on the next page… Continued from the previous page… • WPA (Wi-Fi Protected Access) • 802. 6 Specialized Solutions. Kerberos and EAP (Extensible Authentication Protocol)). configure the connection. benefits and characteristics of using a firewall.18 Identify authentication protocols (For example: CHAP (Challenge Handshake Authentication Protocol). Inc. media tester / certifier.3 Identify the appropriate tool for a given wiring task (For example: wire crimper. PAP (Password Authentication Protocol).16 Define the function of the following remote access protocols and services: • RAS (Remote Access Service) • PPP (Point-to-Point Protocol) • SLIP (Serial Line Internet Protocol) • PPPoE (Point-to-Point Protocol over Ethernet) • PPTP (Point-to-Point Tunneling Protocol) • VPN (Virtual Private Network) • RDP (Remote Desktop Protocol) 2. 3. 3.0 Network Implementation – 25% 3. and physical connectivity. 3. 3.
4. 4.7 Given a troubleshooting scenario involving a network with a particular physical topology (For example: bus. identify the network area affected and the cause of the stated failure. interference. 4. interpret visual indicators (For example: link LEDs (Light Emitting Diode) and collision LEDs (Light Emitting Diode)) to determine the nature of a stated problem. select the appropriate network utility from the following: • Tracert / traceroute • ping • arp • netstat • nbtstat • ipconfig / ifconfig • winipcfg • nslookup / dig 4. Specialized Solutions. identify the utility and interpret the output.0 Network Support – 35% 4. identify the cause of a stated problem: • UNIX / Linux / Mac OS X Server • Netware • Windows • Appleshare IP (Internet Protocol) 4.6 Given a scenario. mesh or ring) and including a network diagram. benefits and characteristics of using antivirus software.Introduction 3. physical connectivity and SOHO (Small Office / Home Office) router).2 Given output from a network diagnostic utility (For example: those utilities listed in objective 4.4 Given a troubleshooting scenario involving a client accessing remote network services. 3.1 Given a troubleshooting scenario. 4. determine the impact of modifying. protocol configuration. 4.8 Given a network troubleshooting scenario involving an infrastructure (For example: wired or wireless) problem. DNS (Domain Name Service) and WINS (Windows Internet Name Service)) for network resources and users. Inc.10 Identify the purpose. identify the cause of the problem (For example: file services.11 Identify the purpose and characteristics of fault tolerance: • Power • Link redundancy • Storage • Services 3.1).3 Given a network scenario. adding or removing network services (For example: DHCP (Dynamic Host Configuration Protocol).5 Given a troubleshooting scenario between a client and the following server environments. network hardware or environment). warm and cold sites Domain 4. authentication failure. star. identify the cause of a stated problem (For example: bad media. 7 .12 Identify the purpose and characteristics of disaster recovery: • Backup / restore • Offsite storage • Hot and cold spares • Hot. print services.
Identify the symptoms and potential causes 2. Identify the results and effects of the solution 8.9 Given a network problem scenario. Identify the affected area 3. select an appropriate course of action based on a logical troubleshooting strategy. Inc. Implement an action plan and solution including potential effects 6. Establish what has changed 4. This strategy can include the following steps: 1. Test the result 7.Network + Training & Test Preparation Guide 4. Select the most probable cause 5. Document the solution and process 8 Specialized Solutions. .
"My job is to understand the material so well that I can make it easier for my students to learn than it was for me to learn. Originally in technical sales and sales management with Sprint. Use the Practice Exam Simulator to test your knowledge. results oriented computer specialist who has extensive knowledge of Microsoft networks. and CCNA. Complete the questions and exercises at the end of each segment of this study guide and in the textbook. He is certified as an MCT. Server+. However. In addition he holds the CompTIA certifications of A+. CCSI. teaching classes for most of the national training companies and some regional training companies. such as the one suggested below: You can maximize your multi-media learning experience by using all of the courseware materials as you study for your certification. Suggestion: • • • • • • • Watch each video segment with the study guide in hand. Bill says.Introduction Study Plan Strategies The material in Network+ is not extremely complicated. Bill has been in the computer industry for over 15 years. Your Video Instructor Your video instructor is Bill Ferguson. MCSA. MCDST. Hands-on experience is best. Practice the function on your computer. Use the "Help" button where available. Pause and rewind to review the concepts as often as necessary. 9 . use a study plan. not all concepts and functions can be performed on a workstation. MCSE. Bill has written the "MCDST Study Guide" for Sybex Inc. and Security+. Alabama. This combination of resources will provide a thorough understanding of the concept or function being presented. Make notes in the study guide as necessary for your understanding. MCP+I. In addition. Network+. Bill made his transition to Certified Technical Trainer in 1997 with ExecuTrain. as well as "Designing Security for Windows Server 2003 Network" for Exam Cram2. Bill now runs his own company as an independent contractor in Birmingham. To get the best results from your training. Bill is an enthusiastic. if this is your first exposure to networking." Specialized Solutions. Inc. it may seem so.
The following is a suggestion you may find helpful. Step 1 – Prepare for the Training Obtain the best possible materials and instruction you can find. Since most of us learn in different ways.com). • • • How do you learn best (reading. CONGRATULATIONS. but A+ certification is not required. Certification exams are becoming more and more comprehensive. . there is no one method that will work for everyone. 1999. German. You can locate a testing center and schedule the test on the web. The Network+ test is currently available throughout the world in English. How to Prepare to Ensure Exam Success There are many ways to prepare for the exam. Read through these suggested steps and modify it as necessary to meet your needs. The Network+ exam was launched worldwide April 30. YOU'VE COMPLETED THE 1ST STEP BY SELECTING SPECIALIZED SOLUTIONS TO BE YOUR TRAINING PARTNER! Schedule the test for a few weeks from now so that you will have a guidepost that is constantly reminding you that you need to study the material. Inc. A typical candidate would have A+ certification or equivalent knowledge. The exam is targeted for technicians with 18-24 months experience in the IT industry. French and Japanese. except payment of the test fee. This method is based on utilization of several learning skills. This helps to ensure that a person who has earned the certification actually understands the concepts and functions of networking versus simply memorizing definitions. Who may take the test? Network+ is open to anyone who wants to take the test.Network + Training & Test Preparation Guide How to Take the Test Passing a certification exam takes more than just skimming through a book.com) or any Thomson Prometric testing center (2test. Prometric and VUE testing centers administer the exam. There are no specific requirements. hearing or doing)? What time of day is best for you (night person/morning person)? What are your limits before you get bored (or fall asleep)? 10 Specialized Solutions. You can also call VUE at 877-551-7587 or Thomson Prometric at 888-8956116. You can take the test at any Virtual University Enterprises testing center (vue. watching. You may be surprised at how near you are to a testing center! Evaluate your learning aptitudes.
Put it on your calendar and keep it! The time it takes you to read the text may be different from the time needed to watch the video or do the practice exercises. Specialized Solutions. Re-read the test and review the video presentation. Complete the entire course one time through using the following methods: • • Break the course down into bite size chunks (a chapter or two at a time). Evaluate your active schedule – determine when you have some free time.Introduction Make a plan to learn. • Complete the course a second time. At this time. If you need to. Review the video presentation one more time if necessary. You will also "pick up" some concepts that you missed the first time through. Use the rewind button as often as necessary. Watch the videos that correspond to the chapters you read. set aside the time to learn. just get a feel for it. This workbook will make this task much easier. What you learned in the later chapters may help you get a better understanding of the material the second time through. you want to begin to understand. Your objective is to own the information (make it part of you). 11 . You will be surprised at how much more sense it makes this time. Read through the text to get an understanding of the material. go though the entire course again. Inc. Focus on the areas that you had trouble with the first time. Make an appointment with yourself. If you don't have any free time – MAKE SOME! Be committed to your plan! Step 2 – Do the Coursework (Text and Videos/CDs) Your objective is to get an understanding of the material and the scope of the course. Based on your time to learn (and your schedule). It is not necessary to memorize or even understand the material at this point.
You will be required to show two forms of identification. If you have never taken one of these computergenerated exams. You may not use a laptop computer or have any notes or printed material with you during the exam session. The test administrator will give you a Testing Center Regulations form. All scratch paper or boards are collected at the end of the exam. (the sample test is unrelated to the Network+ exam) to give you a feel for how the test is conducted. which explains the rules you will be expected to comply with during the test. • • • • Did you understand the questions? Did you misinterpret or read more into it than was there? Did you understand the material? Did you read the whole question? Study the areas that you are weak in. including one photo ID. (such as a driver's license or company security ID) before you take the exam. it might be a good idea to take advantage of this feature. It is a closed book exam. Evaluate the questions you missed. You will be asked to sign the form. You will have the opportunity to take a sample test. • • • • 12 Specialized Solutions.Network + Training & Test Preparation Guide Step 3 – Prepare for the Network+ Exam Place the practice exam simulator in your computer's CD-ROM and select the exam you wish to take or practice with. The test administrator will show you to your test computer and will handle any preparations necessary to start the testing tool and display the exam on the computer. Inc. You will be provided with a set amount of scratch paper or a small dry erase board for use during the exam. Step 4 – Take the Certification Exam As you prepare for your certification exam it will be helpful to know what to expect when you arrive at the testing center: • • You will be asked to sign the logbook upon arrival and upon departure. indicating that you understand the regulations and will comply with them. Continue retaking the practice exams and studying the areas that require improvement until you are consistently scoring in the 90% range on the practice exam. .
(such as the RAID and SCSI Information) just before entering the exam site and then immediately upon starting the test. guess. you are given the ability to skip a question. marked or skipped. Before you begin the exam the test administrator will tell you what to do when you complete the exam. Do not read too much into the question. You will also receive a printed Examination Score Report indicating your pass or fail status from the test administrator. mark it and come back to it. The testing center will notify CompTIA of your score and they will confirm your certification with you. Specialized Solutions. but be sure to read it in its entirety.) If you don't receive a passing score: If you do not receive a passing score. You will have plenty of time as long as you use it wisely. It lists your score by objective. Make sure to note if it is a multiple answer question and select the correct amount of answers. Please note: YOU MUST PAY FOR EACH EXAM RETAKE! About This Course This Specialized Solutions Network+ course is a multi-media. If you don't know the answer. put in extra study time in the objective areas that need improvement. 13 . An unanswered question is always wrong! Stay calm. If you know the answer. (At the end of the test when you have the opportunity to review. Make sure ALL questions are answered BEFORE you exit the test!) When you've completed the test and exit the system. If the administrator does not do this. you may call an authorized testing center to schedule a time to retake the exam. At the end of the exam you will be able to see which ones are answered. ask the administrator BEFORE beginning the exam. If you're not quite sure. jotting down their notes on the scratch paper that the testing facility provides. The course contains five instructor led CD-ROMs. Before retaking the exam. If you positively don't know the answer.Introduction HINT . Inc. a Network+ Training & Test Preparation Guide and a practice exam simulator. you can see which questions are not answered. you are given immediate online pass/fail notification and your score. (You don't need to send them the score report. which will enable you to see which areas require improvement if you didn't pass. mark a question or answer a question. answer the question.Some people find it helpful to study the memorization type materials. Trust your first instinct about an answer! Go back and answer any marked or unanswered questions. Sometimes later questions will help answer earlier questions. self-study training system. or if you are unclear about what you should do. skip it. Keep track of the time and pace yourself. Usually.
. Inc.Network + Training & Test Preparation Guide The Video Chapters Include: CD 1: Introduction and Overview Network Topologies Network Technologies Cable Standards Media Connectors CD 2: Media Types Network Components Wireless Technologies Protocols and Standards The OSI Model IP Addressing CD 3: Ports Services WAN Internet Access Remote Access Security Protocols CD 4: Server Operating Systems Client Connectivity Tools for Networking Firewalls Proxy Service Network Connectivity Virtual Local Area Networks Antivirus Software Fault Tolerance Disaster Recovery CD 5: Troubleshooting Network Utilities Troubleshooting Network Services Troubleshooting Topologies Troubleshooting Strategy Preparation for a Certification Test 14 Specialized Solutions.
Specialized Solutions. Inc. It is designed to be an effective study tool that will help you retain the information that is presented in the course. 15 .Introduction This study guide is divided into 11 chapters.
You will also be able to identify the two major network configurations and describe the difference between a LAN and a WAN. Through networking. a network is a system of connecting independent computers so that users may share data. Introduction to Networking There are many different uses for the term "networking. Another advantage of networking is the ability to have a centralized location for document storage. users can access programs. and applications (resources). It is much less expensive to purchase one network printer to serve everyone's needs (or one department's depending on the size of the network) than to purchase a printer for every user. Additionally. An affiliation of broadcasting companies is also called a network (you've heard of NBC?). you understand exactly what a network is. Saving files to one location (usually the file server) makes it easy for everyone to gain access to the files that they need. Benefits of Networking Computers The main reason that we network computers is to be able to share resources.Chapter 1 – Networking Fundamentals Chapter 1 – Networking Fundamentals This chapter introduces you to the basics of networking. This section focuses on what a network is and why they are used so extensively in today's computer environment.) Most companies network their office computers for the simple reason of economics. 17 ." (Taking a floppy disk with the information that you want to share or print to the computer that can provide the desired service. files." Real estate professionals would think of networking as a means to make more sales through talking to people about what they do. But for our purposes. a central file server can keep unauthorized users from accessing confidential or sensitive files. After completing this chapter you will understand why networking is important and how it relates to the computer environment. Inc. Sharing applications ensures that all users are using the same programs (and versions) and makes it much easier to manage documents. A central file server also allows for an easier backup strategy to be implemented. Specialized Solutions. and peripherals without using what is fondly known as the "sneaker net. peripherals. It is very important that. as a networking professional.
the speed of communication between the computers is typically much faster in a LAN. or if its hundreds of computers spread throughout a high-rise office building. A WAN can connect networks from building to building or across the world. Even if the network is merely two computers connected by a cable to share information. When LANs are connected they create a WAN. The Internet is the world's largest WAN. . The main distinction between a LAN and a WAN is that a LAN is confined to a limited area whereas a WAN has no geographical limits. Also. it is still considered a LAN. 18 Specialized Solutions. A LAN is the basic (and smallest) starting point of any computer network. Inc.Network + Training & Test Preparation Guide Local Area Networks (LAN) and Wide Area Networks (WAN) There are two basic structures of network types: • • LAN (Local Area Networks) WAN (Wide Area Networks) LAN WAN A network is classified into one of these groups based upon its size and function.
The mainframe is always the server and anyone who accesses it is always the client. including applications. it would appear that the advantages outweigh the disadvantages. The only true client/server relationship where the roles do not change is the mainframe computer. that is capable of servicing clients who access shared files. It is important to know what a MAN is. log onto the server to access the files or applications that they wish to use. but they are not common. also known as clients. Also. Inc. one for printing (print server). The disadvantages are greater expense and the complexity of installation. or a mail server (E-mail). and expandability. A MAN is larger than a LAN but is limited to a metropolitan area such as a city or county. A large network may have more than one server. Specialized Solutions. A server is a high-end computer that has a very large amount of storage. when the user is getting information from the server. if that same workstation happened to be connected to a printer that another user wanted to access. A workstation is a computer workspace that is connected to a network. there may be a dedicated server for file storage (called a file server). efficiency in backing up the data. 19 . configuration and management may be more challenging. For example. Servers and clients are roles played by computers and users as they interact in their daily activity. that access would cause the workstation to become a server. The advantages of this type of network are central administration. one for applications (application server). and is a client. Users. A network can be either a peer-topeer network or a server-based network. Since the client/server network is the most common choice of businesses today. network security. However. These terms are not interchangeable. including hard disk space and RAM. it is the role they play in the dynamic world of desktops and laptops that changes. A mainframe will handle all the functions. Client/Server Networking In a server-based network there is a dedicated computer called a server that is the central location of resources.Chapter 1 – Networking Fundamentals There is actually a third classification of networks: a MAN (Metropolitan Area Network). The Internet has replaced most MANs today. The Client/Server Relationship A network is classified by how it shares information. since it would be serving the needs of a user (or client).
A disadvantage of the peer-to-peer network is that since users are responsible for their own systems' security.g. Also. Inc.Network + Training & Test Preparation Guide Client/Server Network Peer-to-Peer Networking In a peer-to-peer network there are no separate computers that act as servers. Windows 95 and up) they will be able to communicate via the network. In a peer-to-peer network all computers are equal. This type of network is most often used when fewer than ten computers are involved. and as long as each computer has an operating system capable of client/sharing (e. a peer-to-peer network is difficult to expand. The computers are simply cabled together. network security is unreliable. All of the computers on the network can act as either clients or servers depending upon the needs of the user. A peer-to-peer network is simple and inexpensive to install. Peer-to-Peer Network 20 Specialized Solutions. .
Specialized Solutions. A terminator absorbs the signal and stops signal bounce. The Bus topology is a passive topology. In a Bus network. Setting up a network requires more than just cabling the computers together. refers to its physical layout. Devices on a Bus topology communicate by sending data to a specific address on the network (a device's address). (Network Interface Cards. how the computers will talk to each other (protocols). Only one computer at a time can transmit data on a Bus network or signals will collide and the transmission will fail. are all determined by the topology used. or topology.Chapter 1 – Networking Fundamentals Basic Network Structure (Topology) A network's basic structure. To stop signal bounce. the signal would travel back and forth along the cable and cause what is known as signal bounce. also called Network Adapter Cards). and even how the cabling is run through a building. and how a network will be managed are all potential problems that need to be considered when planning a network. The nodes (computers or devices connected to the network) are all connected along a single cable. map. This cable is called a trunk. or diagram. they do not move the transmissions along. future growth needs. NICs. Inc. This means that the more computers that are connected to a Bus the slower the network becomes as devices are waiting to transmit or retransmit. you will need to know how to choose the network topology that will best suit the needs of your network. the network will go down and devices will not be able to communicate with each other. it prevents other devices from sending data. The signal is sent out on the cable and it travels from one end of the cable to the other. An electronic signal is sent out on the cable to all of the devices connected on the network. if the cable breaks. scheme. only the device whose address matches the address encoded in the signal will respond to the signal. If not prevented. As a network professional. design. There are three standard topologies that a network professional needs to understand: • • • Bus Topology Star Topology Ring Topology Bus Topology The simplest and probably the most used form of network topologies is the Bus topology (sometimes called a linear bus). While the signal is bouncing back and forth. backbone. connectors. However. or segment. a component called a terminator is installed at each end of the cable. Different topologies have different cabling requirements. 21 . The type and capabilities of the equipment that will be used. Devices only listen for data being transmitted.
Inc. however. but the advantage is that if one computer (or the cable that connects one computer to the hub) goes down. The signal is actually boosted and sent on along the cable when it passes through the computers on the network. There are no ends to terminate. The Ring is not a passive topology like the Bus topology. If the hub fails. The data is transmitted around the loop in one direction and passes through each computer on the network. the entire network will go down. the devices are connected in one continuous circle of cable. Star Topology Ring Topology In a Ring topology. the rest of the network will still continue to function. . it can affect the entire network. all devices are connected to a central point called a hub. 22 Specialized Solutions. A disadvantage is that if one computer fails.Network + Training & Test Preparation Guide Star Topology In a Star topology. It requires a lot more cable than the Bus topology.
today's networking professional will encounter many network topologies that are combinations of the above configurations. For example. The Star Ring topology is similar to the Star Bus. These are known as Hybrid topologies.Chapter 1 – Networking Fundamentals With IBM Token Ring networks. some Ethernet networks today are wired using a using multiple hubs. Special Topologies In addition to the above topologies. These are the methods in which a network is actually wired. we have been discussing physical topologies. Also. Inc. It consists of several Star topology networks that are linked using linear Bus trunks. you will need to know the difference between a physical and a logical topology. A logical topology. You will be able to see a physical topology. Mesh Topology In the Mesh topology every device is connected to every other device by separate cables and has redundant paths. Token Ring networks are physical stars and logical rings. but the hubs in a Star Ring are connected in a star pattern by a main hub. This is very expensive to install but it is extremely reliable because of the redundant paths. In these networks. the ring is actually in a special type of hub called a Multistation Access Unit (MSAU). they operate between the hubs like a bus topology and are therefore a logical bus. This gives us a physical star topology. is how the network actually works. However. a computer can fail and not prevent the network from functioning. on the other hand. So far. Before you can understand some of these special topologies. Hybrid Topologies The Star Bus topology is a hybrid of the Star and Bus topologies. 23 . Specialized Solutions.
. the topology of a wireless network is that of an "invisible star". 24 Specialized Solutions. .Network + Training & Test Preparation Guide Wireless Topology A Wireless topology is one in which there aren't any cables connecting the network devices to the LAN or one which the LAN uses wireless technology between access points. The benefits of wireless technology will be discussed at length in Chapter 4 of this book. Since each computer has its own connection to the wireless access point (WAP). Inc.
25 .Chapter 1 – Networking Fundamentals Specialized Solutions. Inc.
Another aspect of networks that is related to topology is the way in which the network is accessed by individual devices. and the message is delivered. we create kind of a "party line". Token Passing Ethernet Ethernet uses a system known as Carrier Sense Multiple Access with Collision Detection (CSMA/CD). . Inc. The sending machine then creates a new token to send around the ring that will be grabbed by the next device that wants to transmit data on the network. Since there is only one token. Carrier Sense means the network card listens to the cable for a quiet period during which it can send messages. The two most common network standards are distinguished by their respective media access methods. The method that is used for an individual device to be able to use the network party line is called media access. A token is passed along from device to device until it is received by a computer that needs to transmit. The sending computer grabs the token and encodes it with addressing information for the receiving computer and sends it out on the ring. only one device at a time can communicate on the network. We will also cover access methods in more detail in the chapter "Network Protocols and Standards. With several devices connected to one media. This is based on the media or wiring of the network.Network + Training & Test Preparation Guide Network Access The topologies that we have been discussing describe the way in which the computers and other devices on a network are connected. The receiving computer then sends the token back to the sending computer to let it know that it received the message. Multiple Access means that more than one computer 26 Specialized Solutions. It is passed along from device to device until it arrives at the computer whose addressing information matches the one encoded on the token." Token Passing Token passing is the method of sending data around a Token Ring topology. they are called Token Ring and Ethernet.
Collision Detection is the ability to detect whether messages have collided in transit (neither message will arrive at their destination and both will be retransmitted). Ethernet transmits at 10 Mbps and Fast Ethernet transmits at 100 Mbps. 27 . Collision Detection Fast Ethernet Fast Ethernet was developed to meet the increasing demands on networks.Chapter 1 – Networking Fundamentals can be connected to the same cable. Specialized Solutions. Inc. Fast Ethernet works on the same principals as Ethernet but operates at 10 times the speed of the original.
Signals pass through the hub but are not regenerated or amplified. Passive Hubs A passive hub acts as a connection point only. not all hubs are the same and you must use one that is designed to meet the needs of the network. they are all the same. Essentially. Inc. Passive Hub – Patch Panel 28 Specialized Solutions. . hubs come in a variety of names depending on their function.Network + Training & Test Preparation Guide Hubs and Concentrators More and more networks are using hubs and they are pretty much standard equipment in today's networks. Just remember. Passive hubs do not require any electrical power to function. Hubs can be classified as either passive or active. since they provide a common location for connecting the cabling of a network. they are called MSAUs (Multiple Station Access Units). Today. With a Token Ring. The most common name used with Ethernet is a hub or a concentrator.
3) A variety of cable types can be accommodated. 2) Centralized monitoring of traffic and activity along with diagnostic capabilities are available. An active hub regenerates or amplifies a signal when it is passed through. Inc. This type type of hub requires electrical power to function.Chapter 1 – Networking Fundamentals Active Hubs Most of the hubs used today are active hubs. Specialized Solutions. 4) Expanding the network can be easily accomplished by using hubs. 29 . They have many advantages over other types of networks: 1) If a cable breaks only the portion of the network on that segment is affected. Active Hub Hub-Based Networks Hub-based networks are increasing in popularity.
Inc. Be sure to complete the following exercises and review questions. The two types of networks are LANs and WANs. We also learned about the two basic network classifications of networks: the peer-to-peer network and the server-based network. go back and review the chapter again. star. . and ring. The three main types of topology are bus. If you are having trouble with any of these concepts. Topology is a term we use to describe the logical shape of the connection of computers in a network. A WAN is not geographically limited and typically has greater speed of communication than a WAN. and the Internet is the world's largest WAN.Network + Training & Test Preparation Guide Summary In this chapter we learned that the main reason for networking (as it relates to computers) is the sharing of resources. A LAN is the smallest form and is the basic building block for larger networks. It is important to know the differences between these two classifications and the advantages and disadvantages of each. 30 Specialized Solutions.
31 . Inc. Keyword Active Hub Application Application Server Bus Topology Client Data Fax Server File Server Hub Hybrid Topology LAN Mail Server MAN Media Mesh Topology Network Network Administrator Passive Hub Peer-to-peer Peripheral Print Server Definition Specialized Solutions. Hint: There's a glossary in the back of this book.Chapter 1 – Networking Fundamentals KEYWORDS Exercise Define each of the following keywords.
Network + Training & Test Preparation Guide Keyword Resources Ring Topology Security Server Server-based Sharing Star Topology Token Passing User WAN Wireless Topology Definition 32 Specialized Solutions. Inc. .
Specialized Solutions. What does MAN stand for and why is it no longer in use? 6. What is the main reason for networking computers? 3. Name some disadvantages of a Server-based network. Name some advantages of a Peer-to-Peer network.Chapter 1 – Networking Fundamentals Review Questions . What are the key differences between a local area network (LAN) and a wide area network (WAN)? 2. What is a "sneaker net"? 4. What is the difference between a physical and logical topology? 12.Chapter 1 1. 33 . Name some advantages of a Server-based network. Name two media access methods. Name some disadvantages of a Peer-to-Peer network. Name the three basic topologies. 8. Name some advantages of having centralized documents. 7. 11. 9. 5. 10. Inc.
network operating systems were designed to operate on top of an existing operating system. What is an Operating System? Not that long ago. it is just a pile of metal and plastic. When we are talking about operating systems. if you don't have the software to run it. The main objective is to make sure that the hardware and the applications are all compatible with each other. Specialized Solutions. spreadsheet. it will just sit there. word-processing. Today. Most of today's client and server operating systems have a built-in network operating system. 35 . The operating system is also responsible for the running of applications (e. In this chapter we will explore the features and benefits of the more popular network operating systems. Inc. We will also discuss their minimum requirements and interoperability capabilities. processor time. most networked computers run software that was specifically designed to run both the computer's stand-alone functions as well as its networking functions. hard disk space. The differences between server and client operating systems as well as preemptive and non-preemptive multitasking will be covered as well.g. This chapter is all about the various operating systems with which a networking professional needs to be familiar. Even if you have the best network design composed of the best hardware in the universe. and database programs). and peripherals are all controlled by the operating system (the software).Chapter 2 – Network Operating Systems (NOS) Chapter 2 . A computer needed two sets of software in order to function in a networking environment. but without an operating system. You can get it all set up and turn on the power. When we refer to the operating system in this chapter. what we are really talking about are network operating systems. as well as the operating system. Network operating systems (NOS) are specialized operating systems designed to integrate computers in a networking environment. we are referencing the built-in network operating system component. Hardware resources such as RAM.Network Operating Systems (NOS) Up to this point we have focused on the design aspects of networking.
Most operating systems appear to be performing multiple tasks by alternating between tasks until they are all completed. In non-preemptive multitasking. Non-preemptive multitasking is when the task decides when it is done with the processor. It is used on all of the latest operating systems. Preemptive multitasking began with Windows 95 and the Intel Pentium processor. Non-preemptive Multitasking Multitasking.Network + Training & Test Preparation Guide Preemptive vs. Preemptive multitasking means that the operating system can take control of the processor without a task's permission. 36 Specialized Solutions. . means that an operating system has the ability to perform more than one task at a time. put simply. the processor is never taken away from a task. A true multitasking (multi-processing) operating system is able to process as many tasks as it has processors. Inc.
such as BSD UNIX. It protects critical files and will allow you to revert your system back to normal if anything goes wrong. Help and support is improved from Windows 98 and home networking is made easier than ever. Windows 95/98 also performs very well as a client with both the NetWare and Windows NT operating systems. Peer-to-peer LANs are an excellent choice for the network that has less than ten computers and no need of security (such as a small office environment). Instead. Peer-to-Peer LANs Many smaller networking environments utilize the peer-to-peer network configuration. turning on the computer and answering questions. Then. each workstation may act as either a client or a server depending upon whether it is accessing resources on another workstation or if another workstation is accessing its resources. all you have to do is share any directories and peripherals to the network. Most of the operating systems in use today are already capable of managing this type of network. Microsoft Client. Usually this type of network only shares files and peripheral devices. They use an icon called the Network Neighborhood for desktop access of the network. 37 . or a similar program. Plug-n-Play technology has also made installing a NIC much easier. Windows 95/98 is also able to better identify NICs. Novell NetWare. to communicate with other computers over a network. Specialized Solutions. Usually only NICs and cabling will need to be purchased to implement this kind of network. A peer-to-peer LAN is not a client/server-based network. It is certainly the most economical of the networking choices. Windows 95/98 Windows 95 and Windows 98 are operating systems that include a network operating system. moving photos to the Web. To install a NIC with Windows 95/98 is as simple as installing the card. With NT the only drawback is that you will not be able to utilize NT's advanced security features because Windows 95 is not compatible with the NTFS file system. All shared resources are arranged on a hierarchical basis and displayed in Network Neighborhood. Inc. and archiving music. Windows ME Windows ME is the client operating system that has followed the Windows 9x operating systems. and you have a working network. It is necessary to install the requester software (NetWare Client32 for Windows 95) with NetWare.Chapter 2 – Network Operating Systems (NOS) What is a Network Operating System (NOS)? A NOS is an operating system that includes other software. Their new graphical interface and networking capabilities make them a vast improvement over their predecessors. It is well-suited for editing home movies.
EFS (Encrypting File System). It features file protection. It also uses System Restore. which allows for safety when installing additional software or making changes to the computer's configuration. driver certification. is equipped to be networked easily. Other Peer-to-Peer LANs The following table lists other peer-to-peer LAN software and their manufacturers that the networking professional may come across in real life but are unlikely to be on the test: 38 Specialized Solutions. It also supports Microsoft Management Console (MMC) and group policies. like the rest of the client OS software mentioned here. peer-topeer support for Windows 9x and NT. like ME. IPsec and Kerberos support. a simplified visual design. Inc. multilingual support.Network + Training & Test Preparation Guide Windows 2000 Professional Windows 2000 Professional is the client counterpart to Windows 2000 server. Windows XP Home Windows XP Home edition is the newest edition of Microsoft's OS for home users. It. . remote OS installation. It allows for faster user switching.
the purpose of a network operating system is to connect all devices on a network (computers and peripherals) and to coordinate their usability. Specialized Solutions. This can also provide accessibility and security for all devices on a network. In a Serverbased network. However. Some network operating systems require that different versions are installed depending on whether a computer is the server (provides resources remotely over a network) or a client (uses resources locally). 39 . Apple Computer LanMark Grapevine LAN Products D-Link Systems ACCTon Technology Hayes Microcomputer Products Artisoft Invisible Software Peachtree IBM Corporation Novell Performance Technology Compex WebCorp Server/Client Software In a peer-to-peer network.Chapter 2 – Network Operating Systems (NOS) Software Name 10NetPlus AppleTalk Easy Net GV LAN OS LANsmark LANsoft LANStep LANtastic NET/30 Network OSCBIS OS/2 Warp Personal NetWare POWERLan ReadyLink WEB Manufacturer Digital Communications Associates. the computers act as both a client and a server. it is necessary to have an operating system that can perform in this environment. Inc. Inc.
Servers exist to serve. Administrators set up and manage user accounts and passwords. This 40 Specialized Solutions. Inc.Network + Training & Test Preparation Guide There are two types of networking software that must be considered: • • Client Software Server Software Client Software If you type a command for your stand-alone computer to perform a task. Some networks even cluster server so that more that one server can share a database of information. the operating system has to have the capability to redirect (forward) the request away from the local bus. However. . The server keeps track of who is logged onto a network and what resources have been (or are being) accessed. the command is processed over the computer's internal CPU via the computer's local bus. They are the storage facility for the bulk of the data in a network environment and as such are an excellent point from which to centrally manage a network. Users are required to enter a password before they can log on and gain access. Unlike most client software. server software includes services for the following: • • • Managing User Accounts Security Data Protection Managing User Accounts Servers make it possible to manage users from a central location. Most network administrators provide some sort of fault-tolerance system on the server. the server should be attached to an uninterruptible power supply (UPS). At the very least. Security Administrators can set up the accounts to determine who gets privileges to what resources and change them as needed (including denying access). out onto the network. if you were requesting resources or services that exist on a remote server. This makes it an excellent point from which to perform regular backups. most of the data is stored on the server. and to the server. Server Software As their name implies. Data Protection As we already discussed. The component that handles these requests is called the redirector. They process requests from clients for resources such as files and peripherals. Network security is discussed in greater detail in Chapter 10.
It does not need to know anything about networks. This makes the application program believe that it is simply working with a very large hard drive or with a local printer. etc. If it is a local designator (drive C: for example) the request is passed on to the local bus. which opens the file or transfers the print job to the network printer. called drive designators. It does this by assigning drive letters. or if they need to be redirected to the server. Inc. to resources.Chapter 2 – Network Operating Systems (NOS) provides for load balancing of the server resources as well as fault tolerance if one server were to fail. it is a section of code located in the network operating system that intercepts requests and determines if they are local requests. Specialized Solutions. The Redirector (Requester) The redirector (in Novell NetWare this is called the requester) is responsible for forwarding requests away from the local bus and redirecting them to the server. If it is a network designator the request is forwarded to the server. The purpose of the redirector is to make network resources look like local resources to application programs. 41 . Basically.
It is a reliable operating system that provides performance and security. Directory and file attributes are used to set the types of access for a file or directory such as viewed. NetWare is administered through NetADMIN. NetWare is based upon the industry standard X500 directory architecture. copied. deleted. or changed. With NDS' single point logon. The earliest version (2. It is Novell's push to gain market share and is a way of creating an Intranet. login security provides authentication and verification of user name. and volumes is also handled with NDS. non-shareable. 42 Specialized Solutions. .2) was designed to operate on 286 machines. and account restrictions. a user may logon from anywhere on the network and gain access with all of their assigned rights and privileges intact. Each of them has its own advantages and disadvantages. • NetWare's popularity is due largely to its ability to provide services across multioperating system environments.EXE. Versions 3. It is a hierarchically organized database that provides security. It may be installed in either the client or server format. NetWare provides more than adequate network security by using a combination of approaches. or through NWADMIN. In the past. management. we will take a closer look a some of the more popular ones. NetWare File Services The NetWare file server hard drive may be mapped to a client and the client machine will recognize the drive as a logical drive and be able to access it as it would any other drive in the computer. First.11 operate on 386. 486. which is like the Internet but within a network or company. Version 6. or Pentium machines. web-publishing. In this section.12 and 4.11 is called IntranetWare. name service. routing. Trustee rights regulate which directories and files a user can access. time. NetWare Directory Services (NDS) NDS (NetWare Directory Services) is the core of the NetWare operating system. Version 4. NetWare Security The purpose of a network may be to share resources. Novell NetWare The NetWare operating system has been around for a long time. which is a DOS-based utility. but there will always be data in any network to which access must be restricted. but it is losing market share to Microsoft servers every year.Network + Training & Test Preparation Guide NOS Packages There are a multitude of network operating systems available for use. shared. groups. password. servers. as well as what kind of access they have.5 is now on the market. messaging. and file and print services. it was the most popular server operating system. which is a Windows-based utility. Organization of network resources such as users. Inc. See Chapter 10 for more information on network security.
It is compatible with E-mail programs such as Novell's GroupWise and Microsoft Mail. Inc. or directly to the network. 43 . except an individual workstation. a workstation. NetWare Message Handling Service (MHS) MHS may be installed on any server and configured to be a network wide E-mail system. The file server and the print server can be the same computer. You can send messages to individuals or to groups very easily. You can even send messages to everyone in a group. NetWare Minimum Requirements The following are the minimum installation requirements as specified by Novell for installing their server software: Specialized Solutions.Chapter 2 – Network Operating Systems (NOS) NetWare Print Services NetWare Print Services can support up to 256 printers. Printers may be attached to the server. and finally to the printer. next to the print server. Print requests are first routed to the file server. NetWare also provides a method of using simple commands to send messages to other users on the network. as well as others.
0 or later and the NetWare Client32 for Macintosh OS Specialized Solutions.5 MB 20 MB Client Software The client software may be installed on any computer running any of the following: • • • • • 44 DOS 3.1 or later (Standard or Extended Edition) and the NetWare Client32 for OS/2 OS/2 2.X: CPU RAM Free Hard Drive Space Version 3. Inc. .X: CPU RAM Free Hard Drive Space Version 4.1 or later and the NetWare Client32 for DOS MS Windows 3.11 or OS/2 Warp and the NetWare Client32 for OS/2 Macintosh 6.0 or later and the NetWare Client32 for DOS OS/2 1.Network + Training & Test Preparation Guide Version 2.X: CPU RAM Free Hard Drive Space Version 5: CPU RAM Free Hard Drive Space Pentium Class or higher 64 MB 550 MB 386 or higher 16 MB 105 MB 386 or higher 6 MB 30 MB 286 or higher 2.
interoperability simply means the ability of an operating system to operate with other systems. You must have administrative privileges in order to share anything on a Windows network. Today. The NT Kernel. the Windows servers may be configured to store each workstation's directories in order to provide centralized data management and backups. Windows combines the operating system and the network operating system into one. you may assign directory and filelevel permissions to the data. its popularity is being replaced by Microsoft Windows Servers. or No Access may be set on the directory.File Allocation Table) during installation. Unlike NetWare. which as at the base of all Microsoft's servers. Files in Windows may be shared by using a simple file sharing method similar to sharing files on a peer-to-peer network. The services provided by the server are more powerful and it is easier for programmers to develop software that takes advantage of Microsoft's server/workstation technology. Server is much more powerful so that it may provide network management. but it does have several advantages. The NetWare client can be installed with almost any other operating system. The advanced security features of Windows are not available if you choose the DOS file system (FAT . With this method. Problems do occur when trying to operate within the Windows NT domain. and is limited to the publicly shared files mentioned earlier. offer even more advantages and stronger security than their predecessors. A disadvantage of this is that anyone not using NTFS cannot recognize NTFS directories. Windows NT Advanced Server in 1993. Change. Microsoft released the Windows NT operating system and a network operating system version. Windows 2000 Server and Windows Server 2003. This makes it more difficult to work in multi-operating system environments. As we've already discussed. In order to take maximum advantage of the security features in Windows . The attributes such as Read. Inc. allowing restricted access to individuals or groups. another security method must be utilized. It is possible to use both the NTFS and FAT file systems as long as they are in different partitions on the hard drive. Windows NT has two versions: Server (the server software) and Workstation (the client software). Specialized Solutions. but Windows NT contains services such as NWLink and Gateway Service for NetWare (GSNW) that allow them to work together effectively. This type is performed by each workstation or server publicly sharing a directory on the network. Full Control. Microsoft Windows NT Network Operating System While NetWare was the network operating system of the 80s and early 90s. 45 . Although Server and Workstation can both operate as either stand-alone or network systems. NetWare is extremely efficient at operating with other systems. The NT file system (NTFS) must be utilized in order to take full advantage of Windows security features.Chapter 2 – Network Operating Systems (NOS) NetWare Interoperability As the word implies. The newest of these server operating systems. Windows File Services Like NetWare. actually evolved from a project that was jointly developed by IBM and Microsoft (OS/2).
Rights must be assigned to users in order for them to use any resources or perform any tasks in the domain. Windows Network Services There are many services available in Windows to manage network flow: Messenger Service monitors the network and provides pop-up messages for the user. A printer need only be shared to the network to be accessible to anyone on the network. The following is a list of services included with Windows Server software to ensure NetWare compatibility: NWLink is actually a clone of Novell's IPX/SPX protocol and is used for communication between Microsoft and NetWare.Network + Training & Test Preparation Guide Windows Server Security Security was a major concern in the development of Windows Servers. A domain controller is a server that maintains and manages all accounts. computers. 46 Specialized Solutions. At least one domain controller is assigned to each domain. and resources with a shared security database. Remember.. Windows Print Servers Any workstation or server may perform as a print server in a Windows network. more than one printer can be installed to any machine.) Installing a network printer is just like installing a local printer. Workstation Service is the redirector service. especially with the latest Windows Server 2003 family. Browser Service provides a list of all available domain and workgroup servers. See Chapter 10 for more information on network security. (Of course a user still has to be assigned the permission to access a resource. except that you are asked if it is to be a network or local printer. Inc. Microsoft uses domains to control access and authenticate users and computers. Server Service provides access to network resources. Even if you are installing a local printer. and user rights. you are given the option to share it to the network. Printing is as easy as selecting the printer that you want to use (assuming that you have the appropriate permissions). Microsoft wanted to make NT as compatible with NetWare as possible. Alerter Service sends the notifications that are monitored by the messenger service. permissions. . Interoperability As Novell NetWare was the "big kid on the block" when NT came on the scene. This trend continued with the latest Windows server operating systems (Windows 2000 Server and Windows Server 2003. A domain is simply a group of users..
Previous Microsoft server operating systems were built to serve and then had security features to protect them. 47 . when using Windows Server 2003 you typically must remove or configure security boundaries in order to get the server to. Installing GSNW automatically installs the NWLink protocol as well. it has more "locked down" security templates that make it less likely that users will try to go around the security. CSNW (Client Services for NetWare) is the Microsoft service that allows workstations to use file and print services on a NetWare server. DSMN (Directory Service Manager for NetWare) is another add-on utility that is used to integrate user and group account information between the two operating systems.0) than the previous version in Windows 2000 (IIS 5. Active Directory is a directory service that stores information about objects on a network and makes this information available to both users and administrators. In contrast. This is necessary because all Microsoft client workstations in a domain must connect to a NetWare server through a single contact point. Probably the biggest feature in Windows 2000 server is the addition of Active Directory. Windows 2000 Server Windows 2000 server is the server-side OS to Windows 2000 Professional. It also offers an improved version of NTFS and fault tolerant versions of RAID on dynamic drives. Group policies can be utilized with server 2000. UNIX Operating Systems UNIX stands for UNiplexed Information and Computing System. Even though UNIX was not designed as a network operating system it can be.. but it adds many features that are designed exclusively for security. which govern what users can see and do on the network. Windows Server 2003 is the first Windows server that was built primarily with security in mind. This software is not included with Netware but can be purchased separately. In addition..0). Migration Tool for NetWare is a tool used to convert from NetWare to Windows. Its purpose is to move (called migrating) NetWare account information to Microsoft's domain controller.well serve.Chapter 2 – Network Operating Systems (NOS) GSNW (Gateway Services for NetWare) provides the gateway between an Microsoft domain and the NetWare server. Windows Server 2003 offers a more secure Web Server (IIS 6. It can be installed on the Microsoft client to allow it to connect the Netware server directly. FPNW (File and Print Service for NetWare) is a utility that enables NetWare clients to access Microsoft file and print services. In fact. Inc. It allows Novell NDS computers to be managed just as Microsoft domain controllers. Installing CSNW automatically installs the NWLink protocol as well. Network performance will decrease as the number of computers accessing the gateway increases. used as such. Windows Server 2003 Windows Server 2003 is the latest in the line of Microsoft server operating systems. and is. It provides all of the advantages of Windows 2000 Server. UNIX is a Specialized Solutions. It allows for a single logon to access resources anywhere on the network.
but rely solely on the UNIX host for resources. which means that it can be changed by a software programmer. . The UNIX-based workstation can run DOS. Like Novell NetWare. but has lost market share since the arrival of NetWare. many variations of Linux have been created over the years such as Caldera and Red Hat. StreetTalk provides directory. as well as others. It is available on both Intel (PC) and PowerPC (Mac) platforms. in fact the software is available for a free download. and messaging services. however.Network + Training & Test Preparation Guide bulky operating system. These terminals are not stand-alone computers. At one time. A UNIX system consists of a host (a central computer) with terminals for the users. Because of its open source nature. as well as file and printer sharing. The multi-tasking UNIX host will run this software as just another application. OS/2. Banyan VINES (Virtual Integrated Network Service) Like Windows. 48 Specialized Solutions. Inc. TCP/IP. UNIX is a multi-tasking. Banyan VINES is a client/server-based network operating system. Linux is open source. VINES was originally based on UNIX and has a directory services application called StreetTalk layered on top. It is primarily used on minicomputers and has many features that are favored in the engineering and scientific environments. It uses a GUI (graphical user interface). VINES is a great performer in multi-operating system environments. A file redirector is used to allow the workstation to store and retrieve UNIX files as if they were in the original format. multi-user. UNIX. Linux is another operating system similar to UNIX. Software is available. and many other features associated with an OS. or Macintosh System 7 for its operating system. At its inception. It is a publicly open system that has made it popular among enthusiasts already familiar with a UNIX interface. Linux was designed to be less expensive than UNIX. it was an extremely popular network operating system. security. to convert the UNIX host into a file server. general-purpose operating system.
In conjunction with Xerox. Macs are known for being used primarily in video or graphic production. and the processor used in Apples today is called PowerPC.Chapter 2 – Network Operating Systems (NOS) The Macintosh ("Mac") was developed by Apple Computer in 1984. they developed what later became known as the mouse and the first GUI display. but users also use them personally. Inc. 49 . both at home and on the go. The Mac OS X is the most current operating system used in conjunction with the Apple computer (at the time of the writing of this book). Specialized Solutions.
A key component in a network operating system is the Redirector (called the Requester in Novell NetWare). In a server-based network. It is important for the networking professional to know the major network operating systems used today. centralization of administration. Study through the chapter again if you need to. Windows NT has Server software for the server and Workstation software for client machines. . (UNIX. Banyan VINES. Without an operating system a computer is just another pile of metal and plastic. and data backups. There still are numerous LANs that use a network operating system over a conventional operating system. the computers may function as either a server (when sharing resources to others on the network) or a client (when sharing the resources of another computer on the network). The main advantages of the server-based network are increased security. the most popular network operating systems also function as the network operating system. Server and client machines typically use different operating systems.). and at least be familiar with others. the client computers rely on the server for their resources. Novell's NetWare allows for client machines to use a variety of operating systems. In a peer-to-peer network. Today. The redirector then routes the request to the proper bus accordingly. such as Novell NetWare and Windows server operating systems. With the redirector.Network + Training & Test Preparation Guide Summary Operating systems are the lifeblood of the computer. etc. Inc. an application is unaware that it is working from a network. 50 Specialized Solutions. Network operating systems allow a computer to function in a network environment. Be sure to complete the following exercises and review questions. The function of the redirector is to determine whether a requested resource is located locally (on the client computer) or exists on the server (remotely).
Chapter 2 – Network Operating Systems (NOS)
KEYWORDS Exercise
Keyword Client Software CSNW DSMN FAT File Server GSNW Interoperability MHS Linux Macintosh Multitasking NDS Non-Preemptive Multitasking NOS NTFS NWLink Preemptive Multitasking Print Server Redirector/Requester Security Server Software UNIX Definition
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Network + Training & Test Preparation Guide
Review Questions
1. What is the difference between an operating system and a network operating system?
What is the difference between preemptive and non-preemptive multitasking?
What is the purpose of the redirector?
NetWare is designed as an operating system that will overlay _____________ environments.
What is NDS?
What are the minimum hardware requirements for installing Novell NetWare version 5?
Define interoperability.
Unlike NetWare, Windows NT combines the _____________ and the ___________________ into one.
What is NTFS?
What is a domain?
What are the minimum hardware requirements for Windows NT Server?
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Chapter 2 – Network Operating Systems (NOS) 12. Name some of the services and protocols that Microsoft included with Windows NT to ensure interoperability with NetWare.
What OS is similar to UNIX and is a publicly open system?
What type of computer was developed by Apple computer in 1984?
What type of network would utilize Windows for Workgroups as an operating system?
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Network + Training & Test Preparation Guide
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Chapter 3 – The OSI Model and Communication Standards
Chapter 3- The OSI Model and Communication Standards
In this chapter you will learn about the OSI (Open System Interconnection) model, what it is and its primary function. You will learn about which layer of the OSI model handles each function, and which devices function at each layer. We will also discuss the IEEE 802 standards as well as touch on various protocols and how they relate to the OSI Model. The OSI model and IEEE 802 Standards are a big part of the Network+ exam.
The Seven Layers of Network Communication
The Open Systems Interface (OSI) model is the most commonly referenced standard in the networking industry today. The International Standards Organization (ISO) released a set of specifications for connecting devices on a network in 1978. These specifications were updated in 1984 to what we know today as the OSI model. The purpose of these specifications is to describe how network hardware and software communicate with one another. These specifications allow hardware and software manufacturers to develop products that are compatible with each other. The OSI model is designed as a framework that allows communication between similar and dissimilar computer systems across a network. The OSI Model was created after many of the protocols it represents were already in use. As a result, some of the information regarding these protocols may appear to be inconsistent with the OSI Model. There are seven steps required to prepare data for transmission between the sending application and the receiving application. The OSI model represents these seven steps as seven layers. These layers are used extensively in network environments and it is imperative that the networking professional understand the different layers and their functions. The OSI model defines the rules involving how network devices will contact each other, and how they will communicate if they are using different languages. The OSI model also defines how a device knows when to transmit; when not to transmit; and how to make sure that transmissions are received correctly by the recipient. Even how the physical media is arranged and connected; how the data will flow (at what speed); and how bits are represented on the medium are defined within these specifications.
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Network + Training & Test Preparation Guide
The Seven Layers of OSI The first thing you should notice is we've listed the layers from the top down. This model is usually represented in this way because we refer to the layers as upper and lower layers, depending upon their functions.
Seven Layers of the OSI Model
The following is a summary of the seven layers of the OSI model starting with the top layer: Application Layer This layer of the OSI Model defines how network services or applications interact with the network. These services include file, print, and messaging services. Error recovery may also be a function of the Application layer. The Application layer is responsible for communication between a user's application and the network. This is not the actual application or program, simply a support layer that allows an application to use the network by acting as a translator. This is the layer that allows users to send E-mail, transfer files across the network, or access a
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without duplication. (so that an IBM compatible computer may communicate with a Macintosh. and data encryption. etc. Transport Layer The Transport layer is responsible for the errorfree delivery of the transmitted data. 57 . or receive. protocol conversion. As its name implies. The Transport layer is responsible for delivering data that is in sequence. This layer enables computer applications to communicate with applications on remote machines as if they were local.) character set conversion. The presentation layer acts as a translator between an application's native format and the network. bit ordering. This layer is responsible for establishing. For example. It translates data into a format that is compatible with the network. Only the data after the last transmission will have to be retransmitted after a failure. and prepare it for its journey. or full-duplex communication. The Transport layer is also responsible for packaging. and then the Presentation layer of the receiving computer translates the data back into a format that is compatible with the computer. and un-packaging the data for transport. This layer is also responsible for data compression. and when. Each connection is called a session. If Specialized Solutions. add any addressing information and error correction information. The Transport layer accepts packets from the Session layer and repackages them. they will be combined. These checkpoints ensure that all data is sent (or received) and make it possible to limit retransmissions in the event of a network failure during transmission. managing. It is responsible for resizing them before being sent to the destination computer. Sessions may be established using simplex. half-duplex. The redirector is responsible for making network services appear to be local services to a computer. The Session layer controls the communication between the two computers and determines who can transmit. it presents data to the application layer. It is also responsible for security and other functions that allow two applications to communicate over the network. interpreting graphics commands. Presentation Layer The Presentation layer is the translator for the network. In short. if the packets are too small.Chapter 3 – The OSI Model and Communication Standards network database. and ending connections. Session Layer The Session layer organizes the flow of data between devices. It provides a logical connection between the two devices. it will break the data into packets. The network redirector operates at this layer. The Session layer organizes data synchronization and also inserts checkpoints in the data. Inc. The Session layer uses a name lookup service such as NetBIOS to identify and establish sessions between two computers. and error free.
it will be un-packed. the Transport layer will sort out the problems and request that missing packets be retransmitted. The Transport layer of the destination computer reassembles the data (returns it to its original state) and checks for errors and duplications. Connectionless protocols are faster. Should an error occur. however. segmentation information and routing information. The Network layer is responsible for communication between computers via their IP addresses. Its header includes the hardware address of the sending and destination NIC cards. If the sending computer does not receive an acknowledgement. error free manner. It translates logical network addresses into physical machine addresses and determines the best route to the destination computer. When the data is received. (These addresses are hardwired onto the NIC by the manufacturers. This is accomplished through various error control and other protocol-dependent features. UDP is a connectionless protocol. This layer also reassembles the data before passing it up to the Transport layer on the receiving side. the destination computer will send an acknowledgement that the data was received. It receives a packet from the Network layer and packages it into what is called a frame. In an ideal world. The network layer handles all the routing information as packets travel from one network to another. TCP and UDP are Transport layer protocols. especially on large intranetworks where there may be more than one way to reach a destination. 58 Specialized Solutions. Data Link Layer The Data Link layer is the second lowest layer in the OSI model. . This controls network congestion. TCP is a connection-oriented protocol. Once the data is reassembled. they will be broken into smaller packets. This layer makes routing decisions for transmissions that are further away than a single link. For example. Network Layer The hardware that is used to construct the network plays an important role at this layer.Network + Training & Test Preparation Guide they are too large. the Transport layer is responsible for the guaranteed delivery of packets. IP and IPX are Network layer protocols. Routers and NICs function on this layer. and then assembled and sent up to the Session layer. but connection-oriented protocols are more reliable. it will retransmit after a specified amount of time. This layer is also responsible for breaking packets into smaller chunks.) It also includes control information such as frame type. delivery of packets is not guaranteed. the largest frame size on an Ethernet is 1.518 bytes and the smallest is 64 bytes. Inc. The sending computer does not send any more data until it receives the acknowledgement for the previous transmission. if they are larger than the largest acceptable frame size on a network. checked for errors. stripped of its addressing information. all data packets will be sent and retrieved in an orderly. When you are using a connection-oriented protocol. When you are using a connectionless protocol.
They accomplished this by splitting the Data Link layer into two sub-layers. the data is sent out on the wire to all computers. The IEEE Committee thought that the Data Link layer needed to be further defined. The MAC address is another name for the 12-digit (6 byte or 48 bits) hexadecimal address that is hardwired on the NIC by the manufacturer. The IEEE 802.Chapter 3 – The OSI Model and Communication Standards In addition. The LLC sub-layer provides SAPs (Service Access Points) that are used by other computers to transfer information to the upper OSI layers. it accepts the data and passes it up to the next layer. TCP/IP is somewhat "self healing". If the calculation does not check out. it will automatically resend the packet. then it discards the data. If it is. This sub-layer communicates directly with NICs using the MAC address. If it is not. The way that a network shares the channel is called its carrier access method. Logical Link Control (LLC) The Logical Link Control (LLC) sub-layer of the Data Link layer is the upper of the two sub-layers. it is not unheard of for these addresses to be duplicated even with these precautions having been taken. It adds a trailer to the frame that includes the CRC (Cyclic Redundancy Check). 59 . NetBIOS or NetWare and may also assign sequence numbers to frames and track acknowledgements. Media Access Control (MAC) The Media Access Control (MAC) sub-layer of the Data Link layer controls the way that multiple computers share the same media channel. The Logical Link Control layer is concerned with managing traffic over the physical medium. The frame is accepted by the Physical layer of all of the computers on the network and passed up to the Data Link layer. Token Passing. and Demand Priority. it assumes the data was not damaged in transmission and sends an acknowledgement to the sending computer.2 standard defines how this takes place. It is the Data Link layer that determines whether the message is for an individual computer or not. the destination computer will not send an acknowledgement. It is responsible for connecting two computers on a network and maintaining that link. the Data Link layer is responsible for error-free transmissions. It identifies a line protocol. If the Data Link layer in the destination computer comes up with the same value when it receives the frame. such as SDLC. In this way. (they are the vendor code that is assigned to a manufacturer by the IEEE Committee) and the last 6-digits identify the NIC (host). MAC addresses are copied to RAM when a NIC is initialized. The manufacturer is assigned blocks of numbers to assign to NIC cards. The first 3 bytes (6-digits) identify the manufacturer. Inc. It uniquely identifies devices on the same medium. The following is an example of a MAC address: Specialized Solutions. Although quite rare. The combination of these numbers assures that each NIC that is manufactured (by any vendor) will have a unique MAC address. When the sending computer does not receive and acknowledgement. The CRC is simply a calculation that assigns a value to the frame. In a broadcast network such as Ethernet. The three main types of access methods are Contention (CSMA/CD & CSMA/CA).
Bridges operate at the Data Link layer. Repeaters. . Inc. Point to point communication is often used between switches and routers on a network. Note: For more information on the OSI Model. The physical characteristics of a network will affect the specifications of the Physical layer.iso. It identifies the NIC. It is responsible for the mechanical and electrical functions of transmitting data over a network. and determines when and how data may be transmitted. Physical Layer The Physical layer is the bottom layer of the OSI model. Multipoint communication is the process of one device communicating with multiple devices on a network. and what each one will do. an Ethernet network using UTP would have different specifications than an Ethernet network using Fiber Optic cable. Point-topoint communication is the process of one device communicating with one other device .Network + Training & Test Preparation Guide 00-00-13-35-FD-AB The first 3 bytes (00-00-13) identify the manufacturer of the card. all operate at the Physical layer of the OSI model. The Physical layer is not concerned with the contents of the packets. visit www. 60 Specialized Solutions. Switches. data work at the Data Link layer of the OSI model. Point-to-point and multipoint connections are addressed at the Physical layer. The last 3 bytes (35FD-AB) are the Device ID that is unique to the associated Vendor ID. Bridges are devices that connect network segments and filter data using MAC addresses. synchronizes the data. The Physical layer of the receiving computer converts the bits back into frames. which are intelligent hubs that use MAC addresses to send packets. It converts the data into the raw bits and signals (1's and 0's) that are actually transmitted over the network medium. it is only concerned with the physical elements of the network and the transmission and reception of signals. hubs and transceivers. It specifies such things as how many pins a network connector will have. It is the only layer of the OSI model that communicates directly with its peer on another computer.ch/. For example.
Chapter 3 – The OSI Model and Communication Standards Specialized Solutions. 61 . Inc.
Each protocol will communicate with its peer or equivalent on the other computer. The Presentation layer passes the modified packet down to the Session layer. The affect of this layering is that communication is seemingly only taking place between the associated layers of the two computers. In addition to reading the headers and performing the instructions. When the destination computer receives the data. This is accomplished by each layer (with the exception of the top and bottom layers) adding a header to the message (or removing it on the receiving end) before passing it down (or up) to the next layer. The request is then passed to the Presentation layer where a header is added to the message. When it arrives at the Application layer of the destination computer. or suite. and provides services to the layer directly above it. As the packet travels up through the layers. each layer is also responsible for adding or removing headers so that the data is ready to be interpreted by the next layer. These subtasks are stacked in such a way that together they complete a whole task. in effect there is a logical or virtual connection made directly between the two associated layers.Network + Training & Test Preparation Guide Protocol Stacks When more than one protocol is necessary to accomplish a task. TCP/IP is a common example of a protocol stack. In order for computers to communicate with each other they need to be using the same protocol stacks. Each protocol receives services from the layer directly below it. For example: You send a request for services to the server. the process of moving through the layers is reversed. This process continues until the packet reaches the Physical layer.) The request is in the form of a packet. each layer reads and performs the tasks specified in its peer's header before passing the packet up to the next layer. Even though the data is passed down through the sending computer's layers. simply a support layer to allow applications to perform network functions. the Application layer is not the actual application. 62 Specialized Solutions. Inc. Communication Between Peer Layers Most network models utilize this layered architecture. . over the network medium. You are communicating directly with the Application layer. This is called a protocol stack. protocols can be layered so that specific protocols handle their appropriate subtasks at specific layers of the OSI model. and up through the receiving computer's layers. Headers contain instructions for tasks that need to be performed at that level. which also adds a header and passes the packet down to the Transport layer. the data is back in its original form so that it may be interpreted by you and the request is considered processed. In this way even completely dissimilar systems running different operating systems will be able to communicate. (Remember. it simply converts the packet into a bit stream and sends it out onto the network medium. The Physical layer does not add a header.
The term packet is appropriate to all of the layers. Inc. they are sometimes referred to by different names at different layers.Chapter 3 – The OSI Model and Communication Standards Note: Packets (also called service data units) are made up of data and headers acquired from upper layers. but the following table lists the other names that might be associated with them at the various layers: Physical Layer Data Link Layer Network Layer Transport Layer Session Layer Presentation Layer Application Layer Signals or Bits or Data Stream into Frames Frames into Packets Frames or Datagrams into Segments Segments into data Data Data Data into Data Files or Messages Specialized Solutions. Because of this. 63 .
The following mnemonics are commonly used to help remember the layers: 64 Specialized Solutions. as in the case of the TCP/IP protocol. By relating various protocols to the OSI model. Flow of Data As part of the Network+ Certification program. The various layers of the protocol are communicating as though they have virtual connections. we can better understand how they communicate across the layers. some of the components or layers may actually do the work of several layers of the OSI Model. you must keep in mind that it was created after many popular protocols had already been developed. the OSI Model is not a protocol. This means that if you were to attempt to map a protocol or a standard directly to the OSI model.Network + Training & Test Preparation Guide OSI and the Real World When working with the OSI model. This communication will take place as long as both computers are using the same protocols. Inc. . Data will travel from one computer to another on a network from the Application layer to the Physical layer on the sending computer. Also. In fact. Its purpose is to provide a graphical image of how network protocols work together to provide communication between two computers. it would not match. you will need to know the seven layers of the OSI model. then to the Physical layer on the receiving computer and back up to the Application layer.
Without them we would not have as many software or hardware packages available to us. Specialized Solutions. Keep in mind that it isn't actually the layer that performs the task. you do need to remember the different layers and the tasks for which each layer is responsible. The specifications describe how components are supposed to function. etc. The OSI model simply defines which functions need to be completed at each layer and which protocols are to be used at each layer. Inc. This is so that different types of computers with different types of hardware and software can communicate.Chapter 3 – The OSI Model and Communication Standards Mnemonic Away Pizza Sausage Throw Not Do Please OSI Layer Application Presentation Session Transport Network Data Link Physical All People Seem To Need Data Processing Mnemonic No matter how you memorize the layers. because each product would have to be specialized towards each type of computer or operating system. it is the appropriate hardware or software that does the work. 65 . These specifications make it possible for hardware and software manufacturers to create products that will function in different computing environments.
Repeaters A repeater operates at the Physical layer of the OSI model. Inc. as well as where in the OSI model they operate. A repeater amplifies these signals so that they can travel further or across LANs. Routers Routers operate at the Network layer of the OSI model. bridges. Routers are responsible for using logical addresses to move packets from one network to another and deliver them to a host. It regenerates or amplifies a signal across LANs. . This weakening is known as attenuation. you will usually be working in the first three layers of the OSI model: The Physical layer. routers.Network + Training & Test Preparation Guide Devices and the OSI Model As a networking professional. are going to be used when they write a program. They rely on MAC addressing to forward messages to their destination. Most routers today support multiple protocols such as: TCP/IP SNA SLIP X. etc. The networking professional needs to be familiar with these devices. Bridges A bridge operates at the Data Link layer of the OSI model. Data Link layer and the Network layer. Bridges connect two separate networks to form one logical network. and gateways are the most common devices that are used to expand a network. As electrical signals travel across a network medium the signal weakens as a result of resistance from the cabling itself. Programmers usually deal with the upper layers and decide what protocols. These are the layers that have the most to do with hardware devices and other components that you can change. Repeaters.25 IPX/SPX SNAP PPP PPTP XNS Protocols DECnet The following is a list of NON-ROUTABLE protocols: • • • NetBEUI DLC LAT 66 Specialized Solutions.
A computer with special software serves as a gateway and allows for communication between completely dissimilar networks. Inc.Chapter 3 – The OSI Model and Communication Standards Each router has its own table that defines all routes connected to it. Gateways Gateways operate in the upper layers of the OSI model (from the Transport to Application layers. Router tables can be entered manually by a network administrator or they can be dynamically updated using routing protocols such as RIP and OSPF. 67 . A gateway connects two computer networks that use different protocols or even different technologies. A popular example is an SNA Gateway. the brouter will bridge the packet based on its MAC addressing. The gateway translates between the two networks so that they may communicate. Specialized Solutions. If a routable packet is received the brouter will route it using a routing table (make intelligent decisions of how best to route the data). Brouters A brouter operates at both the Data Link and Network layers of the OSI model. but usually in the Application layer). It is a device that combines the functions of the bridge and router. However. if a packet is received from a computer using a nonroutable protocol such as NetBEUI. which can be used to connect an IBM mainframe computer to a Microsoft network.
visit IEEE's web-site at http://www. and if you would like more information on them.3 802.7 802. This project is known as the 802 project (named for the year and month the project started. Inc.Network + Training & Test Preparation Guide IEEE 802 Standards In 1980 the Institute for Electrical and Electronic Engineers.8 802. The following table lists the 802 standards by category: (The ones you need to know are the ones in bold!) Number 802.standards.12 Defines Internetworking Logical Link Control (LLC) Carrier Sense with Multiple Access and Collision Detection (CSMA/CD) Token Bus LAN Token Ring LAN Metropolitan Area Network (MAN) Broadband Technical Advisory Group Fiber Optic Technical Advisory Group Integrated Voice/Data Networks Network Security Wireless Networks Demand Priority Access LAN.6 802. Inc. .1 802. a little surfing might be in order. 100BaseVG AnyLAN If you would like more information on these standards.9 802.4 802.org There are also many other web sites that discuss these standards. but the two sets of standards were designed to be compatible. These standards were prepared before the OSI standards. 68 Specialized Solutions.5 802.10 802. (IEEE) formed a committee to create standards for LANs.ieee.11 802. February 1980).2 802.
69 . Inc.Chapter 3 – The OSI Model and Communication Standards Specialized Solutions.
Protocols and OSI Protocols are the rules that govern communication between computers. but is designed for use with Novell NetWare and Macintosh environments. which will allow a NIC to support multiple protocols. The NIC driver operates at the Media Access Control (MAC) sub-layer of the Data Link layer of the OSI model. The purpose of these standards is to allow operating system vendors (such as Microsoft and Novell) to write multiple drivers for the same NIC. which allows any NDIS-compatible protocol stack to function with any NDIS-compatible driver. and it defines the interface between the Data Link layer NIC driver and the network transport protocol. The driver allows communication between the operating system and the NIC. the network. This is because of the way they work within the OSI layers (on top of one another). This vendor-neutral interface provides a boundary between a protocol and the driver. Network 70 Specialized Solutions. Inc. ODI (Open Data Link Interface) ODI was co-developed by Novell and Apple and serves the same purpose as NDIS.Network + Training & Test Preparation Guide Network Drivers and the OSI Model Just like every other device in a computer. Two sets of standards have been developed to define the interfaces between the NIC and the driver. . NDIS and ODI are incompatible with one another. It defines a way to bind more than one protocol to a single driver. the NIC also needs a device driver to function. The protocols used to communicate in a network environment are called protocol suites or stacks. However. and hence. This way more than one protocol stack can be bound to a single NIC. NDIS (Network Driver Interface Specification) NDIS was co-developed by Microsoft and 3Com Corp.
This binding process is what links the protocol stacks to the NIC driver. but connection-oriented is more reliable. You speak directly to your friend who either agrees or disagrees to come. Protocols that are able to route messages across these devices are called Routable. You have no confirmation (unless he calls you back) that he received the message. There is no guarantee that the message was delivered. In a connectionless communication. Connectionless Communication between computers may be connection-oriented or connectionless. Inc. (This is useful if your network communicates with another entirely dissimilar network. Network protocols reside in the lower layers of the OSI model and handle the addressing and routing functions of network communication. In a connectionless scenario. It is the protocol operating at a certain OSI layer that defines that layer's function. a protocol must be bound to the NIC. Network protocols work at various layers of the OSI model. it is not uncommon for more than one LAN to be connected using a router. Non-Routable Protocols In the early days of networking. Transport layer protocols reside in the middle layers of the OSI model and are responsible for establishing sessions and ensuring that data is sent and received error free. it would be like calling your friend and simply leaving a message on his answering machine. the data is simply sent and assumed to be received. LANs were usually just one network that served a single company or department. In connection-oriented communication. This form of communication protocol guarantees the delivery of data. and in full. if TCP/IP is bound first. Specialized Solutions. For example. it will then attempt to communicate with the second protocol.Chapter 3 – The OSI Model and Communication Standards protocols are responsible for addressing and routing communication over a network. Connection-Oriented vs. Application layer protocols provide support for application-to-application functions in the upper layers of the OSI Model. Protocols that are unable to send messages across routers are called Non-Routable. It is possible to bind two protocols to one NIC (such as TCP/IP and IPX/SPX) or to have two NICs with one protocol bound to each one. If that fails. Routable vs. 71 . Connection-oriented would be like dialing up your friend to ask them to come to a party. Connectionless communication is faster. Protocol Binding In order to function. the sending and receiving computers actually establish a connection to communicate. The network layer protocols also are responsible for error checking (CRC) functions.) The order in which these protocols are bound to the NIC determines which one the network operating system will attempt to use first. The receiving computer acknowledges that it received the data that was sent. They also handle error checking and acknowledgments of transmitted data. In today's LANs however. the operating system will attempt to communicate using TCP/IP first.
Network + Training & Test Preparation Guide The following is a list (in alphabetical order) of some routable protocols: • • • • • • • • • • • • AppleTalk DECnet IPX/ SPX PPP PPTP SLIP SMB SNA TCP/IP UDP X. Inc. Networking Protocols and Stacks The following are common routable networking protocol stacks. It is important that the networking professional know the difference between routable and non-routable protocols and which protocols are routable. . 72 Specialized Solutions. you should be familiar with these protocol stacks and you should know the OSI layer in which their components function.25 XNS Protocols The following is a list of NON-ROUTABLE protocols: • • • DLC LAT NetBEUI Non-routable protocols cannot be used in routed environments (such as the Internet). As a networking professional.
It resides in the Network layer. It has been modified over the years and now contains the following components: • IPX (Internetwork Packet Exchange) – Works on the Network layer of the OSI model and provides connectionless service. At the Application layer it handles application interfaces. MLID (Multiple Link Interface Driver) – Resides in the Data Link layer in the MAC sub-layer. This is the NIC driver in the IPX/SPX suite. It resides in the Network layer. regardless of speed. It chooses the route with the fewest hops. 73 • • • • • • . DECnet This is Digital Equipment Corporation's protocol stack. Datagram Delivery Protocol (DDP) – Provides transmission of packets across a network. At the Presentation Specialized Solutions. RIP (Routing Information Protocol) – This is a simple routing protocol that counts the hops needed to reach a destination. NCP (NetWare Control Protocol) – This control protocol resides at four different layers of the OSI model. IPX/ SPX This protocol is the proprietary protocol that was developed by Novell for Netware servers and clients.) SPX (Sequenced Packet Exchange) – Is a Transport layer protocol and is a connection-oriented protocol. and handles file and print services. It is a routable protocol that can also use TCP/IP and OSI protocols. AppleTalk Filing Protocol (AFP) – Manages file sharing at the Application layer AppleTalk Transaction Protocol (ATP) – Provides connection between two computers at the Transport layer. This stack consists of: • • • • AppleShare – Provides Application layer services for Macintosh. (If data must cross a router SPX is used. It uses the MAC address and is non-routable. It is a routable protocol. Inc.Chapter 3 – The OSI Model and Communication Standards AppleTalk This proprietary protocol stack allows Macintosh systems to operate in a network environment. NLSP (NetWare Link Services Protocol) – This Network layer protocol is also a routing protocol. this protocol takes into consideration link speed and network traffic to make more efficient routing decisions than RIP. In addition to hop count. LSL (Link Support Layer) – Also resides at the Data Link layer and provides the interface between the MLID and the upper layers.
• SAP (Service Access Protocol) – This Application layer protocol is used on servers to broadcast (at specified intervals) the location and services that are available from that server. while APPN provides Network and Transport layer connections. Inc. At the Transport layer it handles sequencing. TCP (Transmission Control Protocol) The TCP/IP suite contains two major protocols. UDP (User Datagram Protocol) UDP provides the datagram service in TCP/IP. NWLink – This Transport layer protocol is Microsoft's version of IPX/SPX. TCP functions at the Transport layer of the OSI model and is a connection-oriented protocol. SMB (Server Message Block) This Microsoft protocol operates at the Presentation layer and is used for communication between the server and the redirector. APPC supports Transport and Session layer services. TCP is responsible for adding header information that contains error checking and flow control information. At the Session layer it establishes and controls sessions. and connection-oriented error control services. It is also layered on IP like TCP. TCP and IP. It also contains several others that the networking professional needs to be familiar with. It is routable and provides support for NetBIOS names. FTP (File Transfer Protocol) This protocol is used for file sharing between computers on a TCP/IP network. so the application must do the error checking and retransmission if necessary. 74 Specialized Solutions. It is used to upload and download files on the Internet and between two computers. It is faster than TCP because it is connectionless. IP (Internet Protocol) IP is a connectionless protocol. A datagram is a kind of packet that has minimum overhead. Missing packets and out-of-sequence data is not checked and no acknowledgements are sent. • Many companies use Netware with the TCP/IP protocol stack. SNA (Systems Network Architecture) This protocol suite is used with IBM mainframes and AS/400 systems. FTP is an Application layer protocol and is available for nearly every operating system. Novell Netware 5. No error checking exists and delivery is not guaranteed. .Network + Training & Test Preparation Guide layer it handles data translation. It operates at the Network layer of the OSI model and is responsible for addressing packets and routing them over the network. We will cover TCP/IP extensively in Chapters 8 & 9. The two main protocols in this stack are APPC (Advanced Peer-to-Peer Communications) and APPN (Advanced Peer-to-Peer Networking). flow control.1 and later installs TCP/IP by default.
ARP (Address Resolution Protocol) ARP is responsible for resolving IP addresses to MAC addresses. It is designed to be reliable and allows for scalability. NTP (Network Time Protocol) Network Time Protocol (NTP) is used in a networked environment to synchronize computer clock times. If you do not need to use passwords. Inc. It is less capable than FTP because it uses UDP rather than TCP. this is also a Network layer protocol. but in reverse. but in addition. RARP (Reverse Address Resolution Protocol) is a related protocol that performs the same function. 75 . It resides in the Network layer. ARP keeps a table of corresponding IP and MAC addresses that have been resolved in the previous 10 minutes. OSPF counts the number of hops to the destination computer. instead of only the number of hops. Telnet This Application layer protocol allows a user to log on and run applications remotely. NFS (Network File System) Sun Microsystems developed NFS as a file and drive sharing system. it will broadcast on the local subnet to determine the MAC address of the computer with the associated IP address. it also takes into consideration the network speed and traffic and makes routing decisions based on the best route. RIP (Routing Information Protocol) RIP (Routing Information Protocol) – This is a simple routing protocol that counts the hops that will be needed to reach a destination. It is an Application layer protocol. It operates like a combination of Telnet and FTP and allows users to access files and drives on remote computers as if they were local resources. without regard to speed.Chapter 3 – The OSI Model and Communication Standards TFTP (Trivial File Transfer Protocol) Trivial File Transfer Protocol (TFTP) is used for transferring files quickly and more simply than the File Transfer Protocol (FTP). OSPF (Open Shortest Path First) Like RIP. then TFTP would be advisable over FTP. Telnet can also be used for remote configuration of servers and network devices such as routers and switches. The local computer acts as a display only and all processing occurs remotely. ARP will add the information to its table for future use. ARP will first check its table and if a matching address is not found. It uses Coordinated Universal Time (UTC) to synchronize computer clock times to a millisecond. It chooses the route with the fewest hops. Specialized Solutions. The computer that has the corresponding IP address will respond to the broadcast by sending its MAC address. making it connectionless. SMTP (Simple Mail Transfer Protocol) SMTP is an Application layer protocol that is responsible for sending E-mail from the sender's server to the recipient's E-mail server.
Because of this. This means that routes change as conditions change. LAT (Local Area Transport) LAT does not have a Network layer. It is bulky and slow and has largely been replaced by TCP/IP. XNS (Xerox Network System) XNS is a proprietary protocol developed by Xerox for their Ethernet LANs. it is out of the administrator's control. This is the host on an X. At each stop. asynchronous terminal traffic over a LAN. 76 Specialized Solutions.25 is also an equipment specification.Network + Training & Test Preparation Guide X. It is typically used between a DECserver and a VAX minicomputer. DLC (Data Link Control) DLC operates at the Data Link layer of the OSI model.25 network is sometimes referred to as a cloud. This is an older packet switching network that uses switches and circuits. . X. making X. but in between. It is a DEC protocol used for interactive. The DTE acts as an endpoint for communications and the DCE acts as an entry point for the DTEs. This is really a type of network that is owned by telephone companies who charge organizations for use. This is not an actual protocol and is not used to perform networking functions. Packets from the same transmission are routed via the best route (and don't necessarily follow the same route) and are reassembled at the receiving end. It uses standard telephone lines and switches. This means that they may not be used with networks that use routers to connect multiple LANs.25 a very slow but very reliable protocol. In addition. Inc. The second part of the specification is the DCE (Data Communications Equipment). This also means that they may not be used to connect to the Internet. Data is routed via the best connection at a given time. Instead. which can be unreliable due to the quality of phone lines.25 X. Data goes in and comes out. X. Non-Routable Protocols The following protocols are non-routable.25 is a packet switching protocol that is sometimes referred to as a public data network (PDN) because it is sometimes used by more than one organization.25 functions take place at the Physical and Network layers and normally interface with a protocol called LAPB (Link Access Procedures-Balanced). The first specification refers to the DTE (Data Terminal Equipment). It was originally used to connect IBM mainframes to HP network printers. the X. only printing functions. it is installed only on the print server and communicates directly with the printer. This protocol is not used for data communication. packets are re-examined to determine whether they are damaged.25 network. which is the main reason that it is non-routable.
Specialized Solutions. but is primarily used today for backward compatibility with existing networks. It is fast.Chapter 3 – The OSI Model and Communication Standards NetBEUI (NetBIOS Extended User Interface) This non-routable protocol works at the Transport layer of the OSI model. which is an advantage if using older MS-DOS-based systems. easy to configure and small. 77 . It may be used with bridges. Inc.
ICMP (Internet Control Message Protocol) ICMP is used in error-handling and control procedures. PPP supports IPX. and notifies upper layers to route around them. . It does not support IPX. and connection release. or DHCP. NetBEUI. DHCP. The main improvement is that it allows clients to connect remotely over the Internet. but it can also be modified manually by the network administrator. RPC is used by the redirector to 78 Specialized Solutions. NWLink and NetBEUI. It provides machineindependent data translations that may include encryption and data descriptions. file transfers. ISO/OSI Standard This is a complete standard with each layer having a protocol (or protocols) mapped directly to it. It provides full networking functions at every layer of the OSI model. PPTP (Point-to-Point Tunneling Protocol) This is an extension to the PPP protocol. PPTP encapsulates TCP/IP.Network + Training & Test Preparation Guide Other Protocols The following are other protocols with which you should be familiar: SLIP (Serial Line Internet Protocol) SLIP supports TCP/IP connections made over serial lines. NetBEUI. It also supports data encryption. SNMP is used extensively with intelligent hubs. SNMP (Simple Network Management Protocol) Devices using TCP/IP use SNMP for controlling network communications. It operates at the Network layer of the OSI model and performs connection services and flow control services. It maintains a database and provides hostname to IP address resolution. Users can establish secure encrypted access to their corporate networks via Virtual Private Networks (VPNs) that PPTP establishes. This database is typically dynamic in today's modern networks. SLIP is not used as much as PPP. This management protocol interfaces with network analyzer software making it easier to manage complex networks. SLIP requires static IP addressing and doesn't support data encryption. RPC (Remote Procedure Call) RPC operates at the Session layer of the OSI model. and other protocols as well as TCP/IP. DNS (Domain Name System) DNS translates names that humans understand into names that the computer understands. XDR (External Data Representation) XDR handles translation and operates at the Presentation layer. Like a traffic report on your radio. PPP (Point-to-Point Protocol) This protocol was developed to replace the SLIP protocol and alleviate some of its limitations. administration. it detects congested areas and links that are down. It handles session establishment. enabling it to use the Internet as a backbone for NWLink and NetBEUI. Inc.
Chapter 3 – The OSI Model and Communication Standards determine if a resource is local or on the network. Specialized Solutions. Inc. 79 . Note: TCP/IP is such an important protocol that we will be covering it in depth later in the text. It makes the remote resources appear local to the computer.
The OSI model is an invaluable tool to the networking professional. . We also learned what type of devices function at various levels of the OSI model and how these devices interact with each other. For example. but also help you to narrow down problems when troubleshooting a network. we learned about the OSI model and its importance in networking. Inc. 80 Specialized Solutions. It is important to note that memorizing the OSI model will not only help you pass the test. you know that networking is taking place and that you have functionality up to layer three. if you can get to the server through a router.Network + Training & Test Preparation Guide Summary In this chapter.
Hint: There's a glossary in the back of this book. 81 . Inc. Keyword 802.Chapter 3 – The OSI Model and Communication Standards KEYWORDS Exercise Define each of the following keywords.x Standards Application Layer Bridge Brouter Data Link Layer Gateway LLC (Logical Link Control) MAC (Media Access Control) Network Layer Non-Routable Protocol OSI Physical Layer Presentation Layer Protocol Stack Repeater Routable Protocol Router Session Layer Transport Layer Definition Specialized Solutions.
What is the function of the Presentation Layer? 11. and ending connections? 12. Inc. What is the function of the Application Layer? 9. Who developed the OSI model? 2. 6. Which OSI layer is responsible for the MAC address? 8. Which OSI layer is responsible for establishing. managing. The ____________ layer is responsible for the mechanical and electrical functions of transmitting data over a network. 5. Which part of this MAC address is the Device ID? 00-01-A5-D3-B4-01 82 Specialized Solutions. What is a MAC address? 13. 3. A router operates at the _________layer of the OSI model. A bridge operates at the ________ layer of the OSI model. 7. 4. A network adapter card operates at the _____ layer of the OSI Model. Name the seven layers of the OSI model.Network + Training & Test Preparation Guide Review Questions – Chapter 3 1. . 10. Data compression takes place at the __________ layer of the OSI.
Chapter 3 – The OSI Model and Communication Standards 14. What is the function of a Gateway? 18. Which is faster. 21. Will this work? Why or Why not? Specialized Solutions. without duplication and error free? 16. Inc. What are NDIS and ODI? 20. You have expanded your NetBEUI network into two segments and are using an intelligent router to optimize network traffic. The Data Link layer has been split into two sub-layers. Which OSI layer is responsible for delivering data in sequence. 83 . 23. What are they? 17. connection-oriented communication or connectionless communication? 22. Which IEEE standard defines the Logical Link Control (LLC) sub-layer? 19. Name as many routable protocols as you can remember. Which OSI layer makes routing decisions? 15. Describe protocol binding.
most networks utilize some type of cable to carry transmissions on the network. or DIX (Digital. and other hardware and peripherals. It also has a transmission speed of 10 Mbps. It is not often used in today's networks. Intel. Inc. Coaxial Cable Coaxial cable consists of a copper core (either solid or stranded) surrounded by plastic foam insulation. The effect of hardware on network performance will be key to your networking operation. 10Base2 (Thinnet) and 10Base5 (Thicknet) in a Bus topology. 85 . and data over longer distances that UTP or STP. Thinnet Thinnet is about ¼-inch thick and is flexible and easy to install. It can transmit voice. network adapter cards. it is less susceptible to EMI than UTP. video. but fortunately for the networking professional there are only three major types that you need to understand. There are numerous kinds of cable. It uses a BNC (British Naval Connector) "T" connector to connect directly to the NIC. and how wireless networks function are among the topics we will cover in this chapter. which is more commonly known as a DB-15 connector. Xerox). How to properly configure and use network adapter cards. but may still be used in some temporary installations such as a construction trailer (although wireless would be a much more likely alternative). The drop cable is connected to the NIC's AUI (Attachment Unit Interface) port connector. Its copper core is thicker than Thinnet and can carry signals farther (maximum segment length is 500 meters or about 1650 feet). It has a maximum segment length of 185 meters (about 606 feet) and a transmission speed of 10 Mbps. Coaxial cable is used in Ethernet Networks.Hardware Media and Peripherals This chapter explores network media. and the hardware aspect of network operations. (and we'll cover them later in this chapter). It uses a device called a transceiver to connect the Thicknet cable to the NIC via a drop cable. along with connectors.Chapter 4 – Hardware Media and Peripherals Chapter 4 . which we will address here. Specialized Solutions. Thicknet Thicknet is about ½-inch thick and fairly rigid. Understanding how different network topologies interact with different types of cable is essential. Network Cabling Although wireless networks do exist. There are several cabling options. Because it is shielded. a braided metallic shield called the ground as well as an outer cover.
It is attached directly to the NIC but allows network signal to flow straight through it as well as to the NIC. it is not as easy to install. all electronic components must operate at the same impedance. They are specified based on their impedance. It is expressed in ohms. In the past. Uses 10Base5 Thicknet 10Base5 Thicknet 10Base2 Thinnet Cable TV ARCnet Type RG-8 RG-11 RG-58 RG-59 RG-62 Impedance – Ohms 50 50 50 75 93 Coaxial Connectors British Naval Connectors (BNC) are used in both Thinnet and Thicknet networks to connect the cable to the computers. In today's networks. BNC Cable Connectors BNC T Connector The BNC T connector is used to connect the network interface card to the cable. as well as how they are attached to the cables. As a networking professional you will need to be familiar with the different types and their uses. Summary of Coaxial Cables Not all coaxial cables are the same. In order for the network to operate at peak performance. Using the wrong cable will cause poor performance and/or failure of the network. . Inc. Impedance is a unit of measurement for resistance to AC voltages. 86 Specialized Solutions.Network + Training & Test Preparation Guide Because it is thicker than Thinnet. Thicknet was used as a backbone to connect several Thinnet networks. it has been replaced by twisted-pair cable and fiber optic cable.
Thicknet uses a device called a transceiver. Both ends of the cable need to be terminated with one end grounded. Inc. The BNC terminator is a connector that has a resistor built in that performs this function.Chapter 4 – Hardware Media and Peripherals BNC Barrel Connector The BNC barrel connector is used to connect two lengths of Thinnet cable together. The transceiver has a port for an AUI connector (AUI port connectors are also called DIX connectors or DB-15 connectors). Specialized Solutions. It is common to connect a Thinnet LAN to a Thicknet backbone using a transceiver. and an AUI cable. It is soldered or crimped onto the cable to make the connection. A transceiver is a device that transmits and receives signals on a network medium. BNC Connectors N Connectors Thicknet uses N connectors that screw on. N Connector Transceivers The computers in a Thicknet network do not connect directly to the cable as with Thinnet. One of the terminators must be grounded. 87 . and is used to connect the device to the network. This cable is called a drop cable or a transceiver cable. BNC Terminator Both ends of the cable must be terminated to absorb signals and eliminate signal bounce.
Vampire Tap Twisted-Pair Cable Twisted-pair cable has become the most popular type of cable used in networks today. most networking professionals used a clamp-on transceiver. It is flexible and easy to install and is the least expensive of all the cable types. This types of connections have been largely replaced by newer cable methods such as twisted-pair and fiber optic cable. . this was time-consuming and it absorbed signal so it was not the common approach. This cable type consists of insulated pair strands of copper wire that are twisted around one another. There are four pair strands in most twisted-pair cables.Network + Training & Test Preparation Guide Transceiver Vampire Taps Although transceivers can be connected by cutting a cable and splicing N connectors and T connectors on the transceiver. The twist helps 88 Specialized Solutions. Instead. Inc. These clamp-on transceivers were often referred to as vampire taps because they utilized sharp teeth that punctured the cable to make the connection.
the faster the signal can be sent through the wires without crosstalk. Currently. Since it is unshielded. There are two types of twisted-pair cables: Unshielded Twisted-Pair (UTP) and Shielded Twisted-Pair (STP).Chapter 4 – Hardware Media and Peripherals prevent crosstalk and sensitivity to EMI. Category 1 2 3 4 5 5e 6 Maximum Data Rate Less than 1 Mbps 4 Mbps 16 Mbps 20 Mbps 100 Mbps 1000 Mbps 1000 Mbps Uses Doorbell Wiring Token Ring and Voice 10BaseT and Token Ring Token Ring ATM and Gigabit Ethernet ATM and Gigabit Ethernet Extremely fast broadband STP Shielded Twisted-Pair (STP) cabling is insulated with a foil mesh between the wire pairs. It has a maximum segment length of 100 meters. Category 5 UTP has a transmission speed of up to 100 Mbps. Twisted Pair Cabling Specialized Solutions. The following is a summary of UTP cables. The tighter the twist. Category 3 cabling has a transmission speed of 10 Mbps. The quality of UTP is based on the number of twists per meter in each pair of wires. 89 . UTP wire typically consists of eight wires or four pairs. it is more sensitive to EMI. Inc. The telephone wire we have all seen in our homes is an example of twisted-pair cabling. there are six categories. This results in less sensitivity to EMI. UTP Unshielded Twisted-Pair (UTP) cabling is the less expensive of the twisted-pair cable types and hence the most popular.
RJ-45 Connector AppleTalk AppleTalk networks utilizing STP cabling uses a DIN-type (DB-9) connector. This is an excellent way to organize network cables. Wall Plates for RJ-45 90 Specialized Solutions. An RJ-11 jack has four connection points where an RJ-45 jack has eight. An RJ-45 connector looks just like a common telephone jack (RJ-11) only larger. The RJ-45 jack's position can therefore be changed from patch panel to patch panel to use a different set of cables for the same connection. Inc. Distribution Panels Distribution racks and shelves are sometimes used to create more room for cables when floor space is at a premium.Network + Training & Test Preparation Guide Twisted-Pair Connectors UTP and STP are usually connected with RJ-45 connectors. The front of the patch panel contains RJ-45 ports (a port is a female counterpart for the RJ-45 jack). These patch panels act like a switchboard where cables are connected and organized. The pin location is a color-coded slot into which the wire is punched down using a special tool punch down tool to make the proper connection by stripping the insulation from the wire without breaking the wire. This gives the network administrator a greater degree of flexibility and provides fault tolerance for the network cabling system. Expandable patch panels (sometimes called punch down blocks) are also used with UTP installations. The wire is assembled in the back of the patch panel in what is called the pin location. . They come in various sizes up to 96 ports and support transmission speeds of up to 10 Gbps . Wall plates are typically used to make the connection to the computers themselves.
IBM Cabling IBM has its own special cabling for use on their Token Ring networks. which reduces signal loss. They do not conform to the same specification as used with standard UTP. This cladding reflects the signal back into the fiber. Because of this feature. Inc. the data cannot be tapped or stolen. IBM cabling is based on its Type. but plastic core fiber-optic cannot carry the signals as far as glass. 91 . . as it is the most expensive and most difficult to install of all the cabling types. However. which is easier to install. One strand transmits and one receives. It also supports much longer segment lengths (several miles). it consists of two separate strands enclosed in a plastic jacket for strength. Fiber-optic cable consists of a glass core surrounded by a coating of cladding (layer of glass or plastic). it is therefore not as common as UTP. SC Connector (for Fiber Optic Cable) ST Connector (for Fiber Optic Cable) Because data is transmitted as light and not as electrical impulses. The following is a summary of IBM Types: Specialized Solutions.) Because data only passes in one direction over fiber-optic cable. (The core can also be made up of plastic.Chapter 4 – Hardware Media and Peripherals Fiber-Optic Cable Fiber-optic cable is the ideal cabling for networking. It supports extremely high bandwidths and is not subject to EMI. fiber-optic is used in networks that need a secure media that transmits at high speeds over long distances.. Signals are sent along the cable as pulses of light.
Two STP – 26 AWG Wire Not Defined Two STP – 26 AWG Wire Two STP –26 AWG Wire Uses Connect between terminals and distribution boxes or between different wiring closets. . Contains a shield for use under carpets. IBM has developed its own cabling complete with its own standards and specifications. two STP and four UTP – maximum length 100 meters (328 feet). 2 3 4 5 6 7 8 9 Fiber Optic Data patch cables.5/125-micron multimode fibers.Network + Training & Test Preparation Guide Type 1 Wire Specs Two STP solid core 22 AWG wires – maximum length 101 meters (331 feet). These are very rarely used in today's modern networks. Six twisted pairs. Same as type 1 but adds voice capability along with data. Lower cost alternative to type 1 or 2. An IBM connector is sometimes called a hermaphrodite. Four UTP with two twists per inch – 22 or 24 AWG wire – maximum cable length is 45 meters (148 feet). Not Defined Two 62. IBM Connector 92 Specialized Solutions. Inc. Cannot be used for 16 Mbps Token Ring. The connector that they developed is unique in that any connector can connect to another as opposed to having "male" and "female" connectors as with other types of connectors. Plenum grade.
Chapter 4 – Hardware Media and Peripherals Summary of Cabling The following table summarizes the specifications for network media: Media Bandwidth (Mbps) Nodes/ Segment 1 Varies 100 30 1 NA Maximum Nodes per Network 1024 260 300 90 1024 Varies Maximum Cable Length (meters) 100 100 500 185 2000 32 UTP STP Coaxial Thicknet Coaxial Thinnet Fiber Optic Infrared 4-100 16-155 10 10 2000 1-10 Note: We will discuss Infrared later in this chapter. Specialized Solutions. 93 . Inc.
The signal flow is bidirectional. Full-Duplex allows for two-way simultaneous transmissions. 10-gauge wire is heavier than 14-gauge wire. An example would be a CB radio transmission where only one person can talk at a time. It is used with digital and utilizes TDM (Time Division Multiplexing). Bandwidth is measured in megabits per seconds (Mbps) or gigabits per second (Gbps). . Bandwidth Bandwidth is a term used to measure the ability of a network medium to transmit data.Baseband vs. Half-Duplex can send transmissions both ways. Broadband allows two or more channels to share the bandwidth of the cable or medium. these fumes would circulate throughout a building in the event of a fire. The signal flow is uni-directional. As the AWG wire number decreases. Both you and the party you are talking to can talk and listen at the same time. PVC is used for the outer cover and the insulation in Polyvinyl Chloride grade cabling. If this type of cable were used in the plenum.Network + Training & Test Preparation Guide Cabling Terms The following are terms that you will encounter when working with network cabling: AWG (American Wire Gauge) AWG is the standard that describes wire thickness. (send and receive) but only one at a time. • Plenum Grade Cabling A plenum is the space between the ceiling and the floor above. Coaxial cable comes in two grades: Polyvinyl Chloride (PVC) and Plenum. a pager can receive a message. Duplex • • Simplex refers to one-way communication only. but cannot send a message. For example. It is used with analog and utilizes TDM (Frequency Division Multiplexing). the telephone utilizes full-duplex transmissions. PVC grade cable is less expensive than Plenum grade cable but it gives off poisonous smoke and gas when burned. Broadband There are two techniques that are used to transmit signals over cable: • Baseband uses the entire capacity of the cable as a single channel. Typical STP and UTP wires are 24-gauge. the wire thickness increases. Inc. 94 Specialized Solutions. fire codes are very specific about what types of cabling can be run in this space. • Simplex vs. For example. For example. This space is used to circulate air through a building. Because this space does circulate air through a building.
) Specialized Solutions. There are many factors that you must consider if you are to meet your networking objectives. Plenum Grade Cables Selecting Cables As a networking professional you will need to determine which kind of cabling medium to use for a given network.) Will plenum grade cable need to be purchased? (If installing cabling in the plenum. local fire codes will need to be addressed. It is therefore specifically designed to be used in these circulation areas. Inc. the flexibility of the medium should be considered. For example. how will the cable need to be installed? (If there are tight corners.Chapter 4 – Hardware Media and Peripherals In contrast. Plenum grade cable is insulated and jacketed in special materials that give off a minimum amount of smoke and fumes. such as: • • • • • Budget Network Traffic Security Needs Size/Distance Environment The installation parameters need to be considered as well. A networking professional must be aware of local fire codes regarding plenum cabling.) Will the cable be installed in "noisy" areas where EMI will be a factor? (If installing the cable near equipment or fluorescent lighting. 95 . shielded cable or fiber optic cable might be more appropriate.
there is no need to use heavy duty cabling when another type would be more cost-effective.) Transmission speeds and. On the other hand.) If security is an issue on the network and the data to be transmitted needs to be secure. Is future growth of the network expected? (Expandability for future growth is easier to achieve if it is planned for in advance. Building a low-cost network that doesn't do the job won't win you any brownie points in the long run! 96 Specialized Solutions. attenuation could have an affect on network performance if you use cabling on a large network where long cable runs are a factor. Inc. cost are issues that will need to be addressed when planning your network.Network + Training & Test Preparation Guide How long will the cable runs need to be? (If the network will be small. . fiber-optic cabling might be appropriate to avoid any tapping. last but not least.
NICs are used to connect the computer to the network. Preparing the Data Computers carry data internally via data pathways called buses. Signals There are two types of signals: Analog: Signals or waveforms that frequently take the form of sine waves. It makes the physical connection to the network. Signals are sent in a continuous flow that represents the start and stop of a data frame. or 0's (off). which constantly vary in one or more values. This is known as serial communication. handles network addressing. most buses are 16-bit or 32-bit. Analog data has an infinite number of possible states. Data traveling via a computer's bus is traveling in parallel because the bits are traveling along side-by-side. This is known as parallel communication. Clocking Clocking is the method used by the NIC to count and pace the number of signals that it sends and receives. This is how the NIC keeps track of how much data has been sent or received.Chapter 4 – Hardware Media and Peripherals Network Interface Cards (NICs) Network Interface Cards or NICs. Signals and Clocking In order to understand how a NIC works. 97 . Specialized Solutions. Digital: Signals that are simple 1's (on). Network cabling moves data in a single data stream. Today. and controls the flow of data on the network. data is moved along in groups. you need to have a basic understanding of signals and clocking. (And of course to translate it back again. The NIC takes data coming from the computer in parallel form and converts it into serial data so that it can be sent along the network cable. Because these paths are side-by-side. We'll discuss the different data bus architectures a little later. are also known as Network Adapter Cards. The purpose of this card is to translate the data that the computer can understand into signals that can be transmitted over the network medium.) This card is installed into an expansion slot on every computer on the network and the cable is connected to the card's port. Inc. Older computers had 8-bit buses which meant that data could be sent 8-bits at a time.
The amount of data that will be sent before a confirmation. How much data each card can hold before overflow occurs. Controlling the Data Flow Before transmitting. The NIC signals the computer to send the data that it wants to transmit and the computer's bus moves the data from memory to the NIC. Once all of these parameters are agreed upon. This makes transferring data much faster. the data is sent to the card's RAM (buffer) until it can be processed. Configurable Options In order for the computer to communicate with the NIC. This informs the other computers on the network of its location. This communication takes place so that both the sending and receiving cards can agree on data flow and confirmation parameters. . If one card is faster or more sophisticated than another card. Each NIC has a unique address that is hardwired onto it by the manufacturer. the NIC may need to be configured. Most computers utilize Direct Memory Access (DMA) and the computer assigns some of its memory space for use by the NIC. The time intervals between data chunks. The IEEE (Institute of Electrical and Electronics Engineers) committee assigns blocks of these unique numbers to each manufacturer. The amount of time between confirmations. DMA (Direct Memory Channel) The NIC must be able to communicate with the computer in order to prepare data for transmission on a network medium. the two cards start sending and receiving data. When this occurs. The speed of the transmission. Before transmission actually takes place the NICs agree on the following points: • • • • • • The maximum size of the groups of data to be sent.Network + Training & Test Preparation Guide Network Addressing/MAC Address The NIC is also responsible for encoding the signals it sends out on the network medium with its unique MAC address. they agree on common parameters so that the data is sent at a speed that can be handled by the slowest card. DMA allows the NIC to access the computer directly without having to go through the CPU. Plug-and-Play cards configure themselves to be compatible with the 98 Specialized Solutions. Data often moves faster than a NIC can process it. Inc. a NIC will send data over the network to the receiving card.
In practice. The main difference is that there are only eight DMA channels available. Base Memory Address The base memory address marks the location in a computer's RAM of the beginning of the buffer area that is reserved for use by a device. Having an IRQ conflict (more than one device sharing an IRQ) can cause problems. Check your system's documentation for assignment and availability of base I/O port addresses.Chapter 4 – Hardware Media and Peripherals operating system so that they may utilize the system's resources. Inc. certain IRQs are almost always used for specific devices. 99 . while others do not use RAM addresses at all. The operating system and the NIC need to have compatible resource settings. This buffer area is used to store incoming and outgoing data frames. not all devices need one. Specialized Solutions. This is sometimes referred to as the RAM start address. Some NICs have settings that allow you to specify the size of the buffer. The most important thing to remember about IRQs is that typically no two devices can use the same interrupt. Typically IRQ5 is used for the network adapter card. and some are set using software. These IRQ lines are part of the system hardware and each device needs its own line. Other cards will need to be configured manually. such as: IRQ (Interrupt Request) The Interrupt Request (IRQ) line is used by the NIC (and other devices) to contact the CPU. Check your system's documentation to determine its current IRQ settings. Each device must have a unique base I/O port number. Some of these settings are configured by using DIP switches or jumper settings. Only devices like NIC cards that need this type of memory access are assigned DMA channels. See Appendix A for common address assignments. in this case the NIC. The good news is that unlike an IRQ. IRQ3 and IRQ15 may also be used if IRQ5 is already assigned. Base I/O Port Address This is the channel through which data flows between a computer's hardware (like a NIC) and the CPU. The device is constantly listening to this channel for commands from the processor. See Appendix A for common IRQ assignments. With a DMA channel. DMA Channel Configuration of Direct Memory Access (DMA) channels is similar to IRQs. these devices can access the memory that they need without interrupting the processor. DMA channels are used by devices that frequently need access to large amounts of memory. These hexadecimal port numbers define a channel between a device and the processor. The main concept to understand is that the NIC is set up to use an IRQ that is not already assigned to another device.
Special software is usually needed to connect a wireless NIC. Connector Type Your NIC may automatically adjust to use the kind of connector that you are using (BNC. 100 Specialized Solutions. or you may have to configure it manually. Wireless NICs Wireless NICs are used to connect wireless network systems to the computer. RJ-45.Network + Training & Test Preparation Guide Ring Speed In Token-Ring networks the ring speed must be set on the NIC. The two speeds available are 4 Mbps or 16 Mbps. They usually use a type of antenna (omnidirectional) and an antenna cable. or both). . If the correct ring speed is not set a computer will not be able to connect to the network and may even cause the network to fail. Wireless LANs are discussed later in this chapter. Inc. they are usually only used in special cases where high-speed direct computer to fiber-optic cable connections are required. Fiber-Optic NICs Due to the high-cost of fiber-optic adapter cards.
Inc. They are also called PC-Card Buses. With this card comes the same expandability enjoyed by desktop PCs. Standard Bus Types There are six data bus architectures found in Intel-based computers: The Industry Standard Architecture (ISA) is an 16-bit bus. including network connectivity. Today most buses are either EISA or PCI. 101 .Chapter 4 – Hardware Media and Peripherals Data Bus Architecture A data bus is a group of parallel conductors (circuit traces) found on the motherboard that is used by the CPU to send and receive data from all the devices in the computer. They are generally 32-bit buses. The Peripheral Component Interconnect (PCI) is a 32-bit bus. Specialized Solutions. The Extended Industry Standard Architecture (EISA) is a 32-bit bus. Laptops PCMCIA (Personal Computer Memory Card International Association) are credit card sized expansion buses that are used in portable computers. Micro Channel (MCA) is a 32 bit bus. but can be a 64-bit bus. Micro Channel is a data bus developed by IBM that requires licensing to be used by manufacturers and isn't used much.
Network + Training & Test Preparation Guide Network Performance Because of the effect that the NIC can have on network performance. Without this feature. 102 Specialized Solutions. Most cards offer features that are designed to improve network performance: Utilizing Direct Memory Access (DMA) improves network performance by allowing the computer to move data directly to the NIC's buffer without going through the CPU. thereby improving network performance. . RAM Buffering holds data in RAM chips that are located on the NIC until it can be processed. it is important that it is configured correctly and optimally. The data would then move directly to system memory leaving the CPU free to process other tasks. Some NICs have onboard microprocessors that eliminate the need of the computer's CPU to process data. Shared Adapter Memory is a method by which a NIC contains RAM that it shares with the computer as if it were actually installed in the computer. Network traffic travels faster than most NICs can process data. This type of card is expensive. Inc. This is a method by which the NIC takes temporary control over a computer's bus. but investing in one can increase network performance by 20 to 70 percent. Both EISA and MCA NICs offer Bus Mastering. thereby bypassing the CPU. Shared System Memory is a method by which the NIC utilizes a portion of the computer's memory to process data. the NIC would be a bottleneck.
This would include historical buildings where local codes would not allow renovations. or open reception areas where the cables would be visible. 103 . or on the road. Wireless networks are more portable than cabled systems. Sometimes wireless systems are used to connect to remote locations such as ocean dwelling oil platforms.Chapter 4 – Hardware Media and Peripherals Wireless Networks The term wireless network implies that it is a network that doesn't use any cabling. Outdoor installations often utilize wireless systems.Wireless networks are frequently used to connect two LANs. – hubs). They are also useful to create a backup system for an existing network. Wireless is also an option for areas where installing cabling would be impossible or unsightly. For example. but through the use of an infrared or radio medium. Wireless networks can be classified into three basic categories: • • Local Area Networks (LANs) – There are fully wireless systems. making them ideal for uses that require frequent moving. but usually the wireless components are members of a wire-based LAN. the office. Mobile Computing . • Why Wireless? Wireless networks are useful if you need to provide a temporary network where running cabling would not be cost effective. Mobility is another reason wireless networks are created. Doctors make rounds all over the hospital and are often not at their desks when they need to access their computers.e. Inc. a company needs to connect two networks located in two nearby buildings. Wireless networks use wireless access points (WAPs) to "connect" the network devices to each other. Extended Local Area Networks . Specialized Solutions. A wireless system can help ensure that the network will still function even in the event of cable breaks. With some applications it is crucial that the network never goes down. People who are constantly on the move are able to access their networks whether they are at home. This is misleading as most wireless networks utilize a system that consists of both cabling and wireless components. They function just like other access points (i.Cellular and satellite technologies are increasing the popularity of wireless networking. a user can access the network from anywhere in the building. With wireless systems.
they are also fairly immune to eavesdropping. Infrared is not sensitive to radio-frequency interference. Infrared transmits very fast because of its high bandwidths. Infrared Networks There are four types of infrared networks: • • • • 104 Reflective Infrared Line-of-Sight Infrared Scatter Infrared Broadband Optical Telepoint Specialized Solutions. and because the transmissions are tightly focused. such as windows. The effective distance between a transmitter and a receiver is limited to about 100 feet.Network + Training & Test Preparation Guide Wireless Antennae Wireless Transmission Methods There are four basic methods of wireless transmissions: • • • • Laser Radio Microwave Infrared You use infrared transmissions every time you use your TV's remote control. These signals need to be rather strong because they can be affected by light sources. . This involves using infrared (below Red) light to carry signals to a receiver. Infrared networks typically broadcast at about 10 Mbps. Inc.
the signal is beamed towards a central unit. Specialized Solutions. uses broadband technology.Chapter 4 – Hardware Media and Peripherals Reflective Infrared With reflective infrared. which are then transmitted over separate frequencies. or direct sequence modulation. Scatter Infrared Transmission rates are slower with this type as the signal is designed to bounce off of walls. ceilings. Transmission speeds with this high-end type are competitive with cable-based systems. until it reaches the receiver. It does. the available frequencies are divided into hops and the transmitters and receivers "hop" from frequency to frequency for a predetermined length of time. The signals can be broadcast via two methods: hopping. This type of transmission is commonly used to connect multiple LAN segments together. Narrow-Band Radio Transmission This is sometimes called single-frequency radio and is similar to broadcasting from a radio station. there must be a direct line-of-sight path between the transmitter and receiver. Spread-Spectrum Radio Transmissions Because spread-spectrum broadcasts over a range of frequencies. require an FCC license and is subject to eavesdropping. it is less susceptible to eavesdropping. 105 . but unblocked it can enable mobile computing over a limited range. Line-of-Sight Infrared With this type of infrared system. The signal can be blocked by heavy concrete or metal walls. etc. The effective distance of the signal is limited to about 100 feet. however. the message is broken into parts (called chips). Radio Transmission Radio transmission wireless is popular with a high bandwidth at 10 Mbps. The transmitter and receiver are tuned into the same frequency and thus it does not require line-of-sight transmission. Inc. In the direct sequence modulation method. as the name implies. Broadband Optical Telepoint Broadband Optical Telepoint. which then routes the signal appropriately. In the hopping method.
These network-style packets are encoded with source and destination address information. This form of microwave communication is used to transmit over shorter distances. There are three forms of mobile computing: • • • Packet-Radio Networking Cellular Networking Satellite Station Networking Packet-Radio Networking Packets are sent via a satellite. mobile computing is a growing technology that provides a nearly limitless range for traveling users of this type of network.Network + Training & Test Preparation Guide Microwave Due to microwave transmission capabilities. The packets sent are called Cellular Digital Packet Data (CDPD) and this form provides very fast communication. Terrestrial Microwave This is used for earth-based communication such as between two buildings. Satellite Station Networking Microwave is currently the most common of the long distance transmission methods in the US. Satellite Microwave This is a very expensive technology and is utilized by very large corporations who pool the billions of dollars required to develop and launch a satellite. 106 Specialized Solutions. Signals are beamed up to the satellite and then sent back down to the appropriate receiver. It is used for line-of-sight communication. . This form of microwave communication is used to transmit globally. Inc. and only the destination device can receive and read the packet. Cellular Networking Cellular networking is achieved via the cellular phone network. or across large flat open areas like bodies of water or deserts.
Chapter 4 – Hardware Media and Peripherals Specialized Solutions. Inc. 107 .
AUI. You should know the types of connectors used for each cable type: BNC. Fiber-Optic cable uses pulses of light to carry signals. As a networking professional. This device is called the network interface card (NIC) and provides the physical connection to the network. you should know the maximum segment lengths for each cable type. Coaxial comes in two types: Thinnet and Thicknet. receives. RJ-45. Inc. and Fiber-Optic.Network + Training & Test Preparation Guide Summary The first part of this chapter covers the various aspects of network media or cables. Twisted Pair can be Unshielded (UTP) or Shielded (STP). Twisted Pair. Radio. and Microwave. 108 Specialized Solutions. There are three primary types of cabling: Coaxial. . Wireless networking is the trend of the future. As a network professional. it is important to understand the concepts associated with wireless networks. In addition. After discussing at network cabling we then took a look at the hardware that acts as the intermediary between the cabling and the computer itself. The four basic wireless types are: Infrared. etc. Finally. it is important for you to be able to configure the network card for optimum performance. transmits. Laser. and controls data flow over the network. It prepares. we took a look at the future.
109 . Inc. Keyword Analog Signals AWG Bandwidth Base I/O Port Address Base Memory Address Baseband BNC Connector Broadband Buffer Cellular Networking Clocking Coaxial Cable Digital Signals DMA (Direct Memory Channel) EISA Bus Fiber-Optic Cable Full-Duplex Half-Duplex IRQ ISA Bus Laser Transmissions Definition Specialized Solutions. Hint: There's a glossary in the back of this book.Chapter 4 – Hardware Media and Peripherals KEYWORDS Exercise Define each of the following keywords.
Network + Training & Test Preparation Guide Keyword MCA Bus Microwave Transmissions Narrow-Band Radio Network Adapter Card Network Interface Card PCI Bus PCMCIA Card Plenum Reflective Infrared Ring Speed RJ-11 Connector RJ-45 Connector Satellite Microwave Scatter Infrared Shielded Twisted Pair Simplex Single-Frequency Radio Spread-Spectrum Radio Terminator Terrestrial Microwave Thicknet Thinnet Transceiver Unshielded Twisted Pair 110 Specialized Solutions. Definition . Inc.
Inc. 111 .Chapter 4 – Hardware Media and Peripherals Keyword Vampire Tap Definition Specialized Solutions.
What type of connectors are used with Coaxial cable? 4. What is the purpose of a transceiver? 5. What is the transmission speed of category 5 cabling? 9. How is a vampire tap connected? 6. Inc. What is the least expensive of the cable types? 112 Specialized Solutions. What is the most expensive cable type? 13. What is the maximum segment length of Thicknet? 3. What type of connector is used with twisted pair cable? 12. . Which twisted pair cabling is less sensitive to EMI? 11. What is the purpose of plenum cabling? 7.Network + Training & Test Preparation Guide Review Questions Chapter 4 1. What is the maximum segment length of UTP? 8. What is the most popular of the cable types? 10. What is the maximum segment length of Thinnet? 2.
Chapter 4 – Hardware Media and Peripherals 14. List some advantages of fiber-optic cable.
15. What does AWG stand for and what is it?
16. Describe baseband.
17. Describe broadband.
18. What is the difference between simplex, half-duplex, and full-duplex communication?
19. What is the function of a network adapter card?
20. In Token Ring networks, what are the two ring speeds available?
21. Where would you expect to find a PCMCIA card?
22. What are some of the reasons you would need to install a wireless network?
23. What are the four basic wireless transmission types?
24. Which is the most secure type of radio wireless network?
25. Which microwave transmission type is used to transmit globally?
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Network + Training & Test Preparation Guide
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Chapter 5 – Network Protocols & Standards
Chapter 5 – Network Protocols & Standards
In previous chapters, we laid the groundwork for understanding networking and we looked at the different networking topologies and cabling options. This chapter explores the various protocols used in network communication. Access methods used by various network protocols will also be discussed, along with the way data is transmitted over a network in packets, or frames. Ethernet is one of the most popular networking architectures. In this chapter, we will discover how Ethernet works, as well as how Token-ring networks function. AppleTalk and ARCNet networks are also included in this chapter. After completing this chapter, you will have a working knowledge of the different network architectures and the access methods that they use. You will also understand how networks send data and what information is included in the frames that are transmitted across the network medium. You will develop an understanding of Ethernet networks and the IEEE standards for Ethernet. You will also know how Token Ring networks function and what hardware is required to make them function. AppleTalk and ARCNet architecture, while not as popular as Ethernet, are still important technologies that the networking professional needs to comprehend. A protocol is a language that computers use to communicate with other computers, in this case, over a network. In Chapter 3, you saw how each layer of the OSI Model has different protocols that define how the information travels. The way these protocols interact is called a protocol stack. The following main protocol stacks are the most important: • • • • • Internet Protocol Suite TCP/IP Novell NetWare's Protocol Suite, IPX/SPX IBM's Systems Network Architecture, SNA Digital's DECnet Apple's AppleTalk
The OSI Model was created at a later date than some of the aforementioned protocols; thus, they do not map directly to the OSI Model. Protocols function at three basic levels: • • Application protocols provide support for application-to-application interaction and data exchange. Transport protocols ensure that data is sent to the correct destination without errors. Specialized Solutions, Inc. 115
Network + Training & Test Preparation Guide • Network protocols route information, handle addressing, and check for errors. Network protocols also set the standard for communicating in different network environments.
A protocol must be bound to the network adapter card, also known as the network interface card (NIC), in order for it to be used with a network computer. In some instances, as in the case of TCP/IP or IPX/SPX, two protocols may be bound to one card. The order in which the operating system will use the protocol is determined by the order in which the protocols are bound to the NIC.
Access Methods
In a network, multiple computers are contending with each other for access to the network media. The rules for determining how a computer may send or receive data on the network is called the access method. The access method that a system uses is designed to prevent simultaneous sending of data along the cable. If two or more computers were to send data at the same time, the data may collide and be destroyed (or partially destroyed). The access method organizes the sending and receiving of data. All computers on the network need to utilize the same access method in order to be consistent in the way that the data is handled. This will ensure that a dominant access method being used by one computer doesn't override access to the cable causing the network to fail. There are three primary access methods: • • CSMA/CD (Carrier-Sense Multiple Access with Collision Detection) or CSMA/CA (Carrier-Sense Multiple Access with Collision Avoidance) Token Passing
• Demand Priority CSMA/CD (Carrier-Sense Multiple Access with Collision Detection) CSMA/CD is known as a contention method. This is because computers on the network compete with each other for the chance to transmit data on the cable. With CSMA/CD each computer on the network checks the network cable for traffic. If it "senses" (carriersense) that the cable is free, it will send data. While there is data traveling on the cable, no computer will transmit data. Occasionally, however, two computers will transmit data at the same time and the data will collide. The Collision Detection aspect of CSMA/CD causes the two computers to stop transmitting and then attempt to retransmit after a specified period of time. Naturally, the more users who are connected to a network, the denser network traffic becomes. Greater network traffic can dramatically slow down the CSMA/CD access method.
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Chapter 5 – Network Protocols & Standards CSMA/CA (Carrier-Sense Multiple Access with Collision Avoidance) This access method is not as popular as CSMA/CD because the sending computer will transmit its intent to transmit before sending out data. Sending out messages that it is about to transmit increases network traffic and slows down network performance. It is, however, the access method that works best with wireless connections; since the wireless channel can be verified before the data is sent. Token Passing The token passing access method is used on networks that utilize the ring topology. A token (a special type of packet) is circulated around the ring from computer to computer. If a computer needs to transmit data on the network, it must wait until it possesses the token. A computer that is waiting to transmit will take control of a free token. It will add additional header and trailer information to the token as well as the data that it wishes to transmit. Data is transmitted in frames. The header information that is added to the token includes sending and receiving addressing information. The trailer includes error control information. When the computer is ready, the token is released back out onto the network and continues around the ring until it reaches the destination computer. The destination computer grabs the token and receives the data. It then adds some data to the token indicating that it received the data and releases the token back out onto the ring. The token continues around the ring until it arrives back at the source computer. The source computer takes the token and confirms that the data it transmitted was received. It then creates a new "free" token and releases it back out on the network to be used by any computer that needs to transmit. If either the source (sending) or destination (receiving) computer detect errors in the data that was transmitted, the frame would be resent. A computer in a Token Ring network must possess a token in order to transmit. Because only one computer at a time may transmit, this is not a contention method and there are no data collisions. (Some more recent versions of the Token Ring network have the capability to pass two tokens around the ring.) Demand Priority The demand priority access method is designed for the 100 Mbps Ethernet standard 100VG-AnyLAN. It has been addressed in the IEEE 802.12 standard and is based on the hubs and end-nodes being the two components that make up a 100VG-AnyLAN network. An end node in a 100VG-AnyLAN could be a computer, router, switch, or bridge. The hub manages network traffic by searching for requests to transmit from all the nodes connected to the network. The hub is responsible for verifying that all end-nodes, addresses, and links are functioning. Demand priority is more efficient than CSMA/CD because there is only traffic between the sending computer, hub, and destination computer, instead of broadcasts over the entire network. Because of the cabling method used with this access method, (four pairs Specialized Solutions, Inc. 117
Network + Training & Test Preparation Guide of wires are used, which enables quartet signaling) computers can send and receive at the same time. Contention can occur with demand priority if two computers transmit at exactly the same time, but it is possible to configure so that certain types of data receive priority when there is contention. If the hub receives two transmissions simultaneously, the one with the highest priority is serviced first. If the two transmissions have the same priority level, they are serviced at the same time by alternating between the requests.
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Data is broken down into small chunks called frames or packets.Chapter 5 – Network Protocols & Standards Network Communications (Frames and Packets) As we've discussed previously. 119 . Data files tend to be quite large. data needs to be processed into a form that can be transmitted across a network medium. and if they were sent out onto the network medium in this form they would overload the network cabling and slow the network dramatically. Error checking information such as Cyclic Redundancy Check (CRC) information. or messages. Instructions for the network indicating how to transmit the data. The destination address of the receiving computer. Specialized Solutions. Session control codes to indicate the need of a retransmission. Another reason for not transmitting data in such large chunks is error detection. The destination computer receives the packets and reassembles them in the correct order to translate it back into the original message. Inc. All packets contain: • • • • • • The source address of the sending computer. This information allows for error checking after the data has been reassembled. Also.) Data is converted to packets in order for it to be moved across the network medium more quickly. The data to be transmitted. only a small portion of the data is affected (and needs to be re-transmitted). (The terms frames and packets are often used interchangeably. but we will use the term packets. Instructions that tell the receiving computer how to reassemble the data. Computer control data such as service requests and commands. if there is a transmission error. Packet Structure Packets may contain: • • • Files. information. The sending computer breaks the data into packets and adds information to each packet in order to make it possible for the receiving computer to reassemble them in the correct order.
. If the results are the same. the source and destination addresses. the trailer contains the error checking information. When the packets are reassembled at the destination computer. the CRC asks the source computer to retransmit. Usually. CRC (Cyclic Redundancy Check) is a mathematical calculation that is calculated at the source computer and attached to the packet. packets can be various sizes. Most files are much larger than this so many packets will be made up to complete the transmission.Network + Training & Test Preparation Guide Packet Components Headers Headers are attached to each packet. the computer assumes that the packets all arrived intact. usually from 512 bytes to 4Kilobytes. If there is a discrepancy. The header contains information such as an alert signal to announce that a packet is being transmitted. Data This part of the packet contains the actual data that is to be transmitted. the calculation is run again. Inc. A Packet 120 Specialized Solutions. Trailer The information in the trailer can vary depending upon the communication method or protocol used in a network. Depending upon the network. and clocking information.
121 .Chapter 5 – Network Protocols & Standards Specialized Solutions. Inc.
or Twisted Pair cable (10BaseT and 100BaseT). Inc. These provide the standards for the railroads. some are wide gauge. but its primary function is maintaining the network link by identifying a line protocol. Logical Link Control (802. Ethernet uses a bus or star topology (10BaseT and 100BaseT use the star topology and 10Base2 and 10Base5 use a bus topology).2) The Logical Link Control layer. as addressed previously. Ethernet is defined in the IEEE 802. Standards work in the Physical and Data Link layers of the OSI model. like NetBIOS (Windows) or NetWare (Novell). There are a number of Ethernet IEEE standards. Not all railroads are the same (some are electric. it is the rails and switches that govern the actual movement of the trains (data). but all railroads that are built to the same standards can exchange cars (data). The standards define the means of communications. Protocols that are used with the OSI model define the rules of communication. Ethernet (802.3) Ethernet is a non-propriety network architecture that was originally developed at the Xerox Palo Alto Research Center (PARC) by Robert Metcalfe and David Boggs.94 Mbps network system that would connect over 100 computers on a one-kilometer cable. and typically transmits at 10 Mbps. It is a baseband system and utilizes the CSMA/CD access method. Thicknet coaxial (10Base5). The original version was a 2. we are going to look at different standards for networks. . For example. The LLC has the ability to track acknowledgements.3 standard and is a method for computers and data systems to connect over shared cabling. some are diesel. is one of two sublayers of the Data-Link layer and is concerned with managing traffic over the physical medium. In this section. in a railroad. It is probably the most popular network architecture used today. data (in this case passengers and freight) is moved in various cars.Network + Training & Test Preparation Guide Network Standards Network standards can best be described as the physical and functional characteristic of a network. The following are the four that transmit at 10 Mbps: • • • • 10BaseT 10Base2 10Base5 10BaseFL 122 Specialized Solutions. There are rules or protocols that govern how the cars are loaded and the origination and destination points. and some are narrow gauge). It can be installed with Thinnet coaxial (10Base2). However.
meaning 10Base5 has a maximum segment length of 500 meters. The minimum distance between nodes is . While 10BaseT can and does work with STP cabling. The maximum number of nodes per network 90. The "2" stands for 2 times 100 meters. (There may be five segments but only three may be populated. 10BaseT has a maximum segment length of 100 meters (Twisted Pair wiring maximum segment length) and it is connected using RJ-45 connectors. and computer aided design. It transmits at 10 Mbps using baseband technology in a bus topology. is 185 meters. to name a few. it is most commonly created with UTP cable. The maximum number of nodes per network 100. Inc. and the maximum number of segments is 5 with 3 being populated. If the segment must exceed this limitation. however. repeaters can be used for longer distances. 10Base5 (Thicknet) 10Base5 uses Thicknet (coaxial) cable. As its name implies.) This is referred to as the "5-4-3 Rule". These applications include video. 100 Mbps IEEE Ethernet Standards The IEEE committee has introduced new specifications for 100 Mbps Ethernet standards that can meet the demands of today's high-bandwidth applications.5 meters. 123 . it transmits at 10 Mbps using baseband technology. 10BaseFL (Fiber Optic) 10BaseFL is the specification for running Ethernet over fiber-optic cable.5 meters. The actual maximum segment length.Chapter 5 – Network Protocols & Standards 10BaseT (Twisted Pair) The "10" in 10BaseT indicates that it transmits at 10 Mbps. The "5" stands for 5 times 100 meters. It transmits at 10 Mbps using baseband technology.5 meters. The minimum distance between nodes is 2. The maximum number of segments containing nodes per network is 3. The "Base" indicates that it uses Baseband technology (single channel). The maximum number of nodes per network is 1024 and the minimum distance between nodes is 2. And the "T" indicates that it uses Twisted Pair cabling. BNC connectors and a transceiver. The maximum number of nodes per segment is 100 in a 10Base5 system. 10Base2 (Thinnet) 10Base2 uses Thinnet (coaxial) cable with BNC connectors in a Bus topology. 10BaseT uses the star topology. The main use for this specification is for long cable runs. The maximum segment length for 10BaseFL is 2000 meters. The two Ethernet standards for 100 Mbps are: • 100BaseVG-AnyLAN Ethernet Specialized Solutions. indicating its maximum segment length. The maximum number of nodes per segment is 30. document and image storage.
124 Specialized Solutions. ATM competes. with Gigabit Ethernet. When you see any of these terms. 10-Gigabit Ethernet is also on the horizon. Gigabit Ethernet is currently being used as the backbone in many larger networks. Gigabit Ethernet is carried primarily on fiber optic cable. The IEEE specification 802.) 100BaseX ("Fast Ethernet") Fast Ethernet (as 100BaseX is sometimes called) is simply an extension to the existing Ethernet 10Base Ethernet standard. they are referring to the same thing.Network + Training & Test Preparation Guide • 100BaseX Ethernet (Fast Ethernet) 100VG-AnyLAN In 100VG-AnyLAN the VG stands for Voice Grade. Gigabit Ethernet Gigabit Ethernet is a transmission technology based on the Ethernet frame format and protocol used in local area networks (LANs). The T4 means that it uses four-pair twisted pair cable. using the CSMA/CD access method. It uses Category 5 twisted pair cable or fiber-optic cable in a Star Bus topology. Because of its intense speed. VG. It is basically a way of transmitting Ethernet frames and Token Ring packets. There are three different specifications: 100BaseT4 (this uses UTP four-pair Category 5) 100BaseTX (this uses UTP or STP two-pair Category 5) 100BaseFX (this uses two-strand fiber-optic) As you know. the 100 means that it transmits at 100 Mbps and the Base means it uses baseband technology. 100BaseVG requires its own hub and cards. It can support the demand priority access method as well as an option for filtering address frames at the hub for added privacy. the TX means it uses two-pair twisted pair cable. although copper can be used with much shorter distances. . It is known by at least four names: 100VG-AnyLAN. This uses a star topology over fiber-optic and Category 4 and 5 twisted pair cable at a data transmission rate of 100 Mbps. and the longest cable length is 250 meters. 100BaseVG. to some degree. Inc. and the FX means fiber-optic cable is used.12 is the standard that defines this technology. (It can be extended longer but it requires special equipment. and provides a data rate of 1 billion bits per second (one gigabit). and AnyLAN. but that will be referred to later in this book.
Inc. 125 . It is also compatible with operating systems such as: • • • • • • • • • Microsoft Windows 2000 Microsoft Windows NT Server Microsoft Windows NT Workstation Microsoft Windows 95 and Windows 98 Microsoft Windows for Workgroups Microsoft LAN Manager IBM LAN Server AppleShare Novell NetWare Ethernet networks may be segmented in order to improve performance.Chapter 5 – Network Protocols & Standards Other Ethernet Considerations Many communication protocols are compatible with Ethernet including TCP/IP. by joining with either a router or a bridge. Specialized Solutions. Ethernet also works in the UNIX environment.
Network + Training & Test Preparation Guide Token Ring (802. The physical ring is in the hub and the logical ring represents the data's path between the nodes. IBM introduced Token Ring around 1984. Inc. The Token Ring access method. it is a star ring with each node connected to a central hub. 126 Specialized Solutions. The computer that wants to transmit takes possession of the token. but is still used today. It is not as popular as Ethernet. Data collisions are avoided because only one computer is transmitting at a time and no other computer is allowed to transmit unless it possesses the token (which won't be released until the previous computer is finished). How it Works Basically. This is so that no other network computer will try to possess it to transmit data. The token is actually a stream of data that allows a computer to transmit data on the cable. Each computer on the network acts as a repeater and regenerates the signal as the token/data frame passes through it. A computer cannot transmit data in a Token Ring environment unless it possesses the token. Actually. Frame Control The information here determines whether the frame is being transmitted to all computers on the network or one specific "end station" computer. and it has a transmission speed of 4 or 16 Mbps. it is known as a data frame. Like Ethernet. Destination Address This is the address of the receiving computer. more than the cable design. and 3). 2.5 standard. While the token is in use by a computer to send data. is what sets Token Ring apart. The name Token Ring implies that the physical layout is that of a ring. This token will travel around the ring until a computer signals that it needs to send data. The data frame is a different type of frame than the token. it uses the baseband technology. The sending computer encodes the data frame with information such as: Start Delimiter This marks the start of the frame.5) The Token Ring architecture is defined in the IEEE 802. . primarily in IBM mini and mainframe systems. The cable used is STP and UTP (IBM types 1. Access Control This sets the frame priority and is also where it is encoded to let the network computers know whether the frame is a token or a data frame. the network creates a token when the first computer comes online.
The beacon is passed from node to node around the ring. If a computer doesn't receive a beacon when expected. Every seven seconds the active monitor will send out a beacon. if there were errors. while IBM says counter-clockwise. The IEEE 802. The active monitor investigates any frames that have traveled the ring more than once and ensures that only one token is traveling the ring at any one time. The frame is then released back out onto the cable where it travels back to the sending computer. it will notify the monitor that it didn't receive an expected signal. This computer. as well as its own address. After encoding the data frame. Message This is the data or file to be transmitted.Chapter 5 – Network Protocols & Standards Source Address This is the address of the sending computer. has the responsibility of making sure that frames are being sent and received accurately. It then encodes the frame with information indicating that it received the data and there were no errors detected. called the active monitor. Inc. Note: Data travels in only one direction on a Token Ring network. the first computer to come online is assigned to monitor network activity. Its address is checked to confirm that there are no duplicate addresses on the network and the other computers on the ring are notified of the new computer's active status. Cyclic Redundancy Check (CRC) This is information for error detection. it would indicate that the data needed to be retransmitted.5 standards say it travels clockwise. the sending computer releases it out onto the network where it travels around the ring until it reaches the destination address. Whether it travels clockwise or counter-clockwise is a matter of convention. Beaconing In a Token Ring environment. Assuming that the frame acknowledges that the transmission was successful. . Or. the active monitor performs a process known as beaconing. The receiving computer copies the data into its buffer. 127 Specialized Solutions. As each new computer comes online. This signal contains the address of its upstream neighbor. the Token Ring network initializes it so that it may join the ring. The network will then attempt to diagnose and repair the problem without disrupting the entire network. To accomplish this task. the old frame is removed and the computer creates a new token and releases it back out onto the ring.
Using STP. When a computer is connected. Using UTP. Media filters convert cable connectors between the adapter card and the telephone jack (RJ-45/RJ-11) and reduce line noise. Using the RJ connectors allows for one cable run to connect both data and telephone equipment. MAUs can sense when one of the connected computers fails.Network + Training & Test Preparation Guide Multistation Access Unit (The Hub) The actual ring in a Token Ring network is in the hub. There is some contention as to the maximum distance from the computer to the hub using Type 3 cable. the failure of one computer will bring down the rest of the network. Instead the connectors can be flipped over to connect to one another. as there are no male and female ends. each ring can connect up to 260 computers. but some vendors state that it is as much as 152 meters. Each node is connected to the hub via a cable. This is known as a hermaphroditic connector. The Type 128 Specialized Solutions. These patch cables extend the connection between the computer and the hub or between two hubs. Token Ring Patch Cables IBM Type 6 cable is used for patch cables in a Token Ring network. the internal ring converts to an external ring at each connection point. The minimum distance using either STP or UTP is 2. Token Ring Cabling STP or UTP is used to connect each node to the hub. such as: • • • MAU (Multistation Access Unit) MSAU (Multistation Access Unit) SMAU (Smart Multistation Access Unit) A Token Ring network can be expanded to have as many as 33 hubs. This hub is known by a few names. IBM states that it is only 46 meters. Using UTP. each ring can connect up to 72 computers. Type 1 has a maximum distance from the computer to the hub of 101 meters. Using STP. . Token Ring Connectors Token Ring networks use MIC (Media Interface Connectors) connectors for Type 1 and Type 2 cable. Type 3 cable is connected with RJ-45 (8-pin) connectors if using four-pair or RJ-11 (4-pin) if using two-pair. just as in other networks that use a hub. Inc. In a pure token passing environment. Most Token Ring networks use IBM Type 3 UTP cabling.5 meters. the maximum distance from the computer to the hub is 100 meters. it is only about 45 meters. but types 1 and 2 may also be used. The faulty node is then disconnected from the ring so as not to affect the rest of the network. The maximum distance between two MAUs is 152 meters.
AppleTalk AppleTalk is the network architecture used in a Macintosh environment. The 16 Mbps card allows for a larger frame length. therefore network capabilities are built into all Macintosh computers. Token Ring Fiber-Optic Using fiber-optic cabling in a Token Ring network can increase the range up to ten times that of copper. thereby decreasing the number of transmissions needed for data transfers. Inc. 129 . care must be taken that all cards on the network are compatible. AppleTalk is included with the Macintosh operating system software. All cards on the network need to be set at the same speed. Token Ring Adapter Cards A Token Ring has two transmission speeds: 4 Mbps and 16 Mbps. it is still an environment that you may be dealing with as a networking professional. Token ring networks are well suited to fiber-optic cable. Although it is not nearly as popular as the Ethernet or Token Ring architectures. Using a pair of repeaters. Token Ring Repeaters Just as in other network environments. A 16 Mbps card can slow to 4 Mbps. hubs may be up to 730 meters apart with Type 1 or Type 2 cable and up to 365 meters apart using Type 3 cable. Type 6 may also be used to increase the length of Type 3 cable or for connecting computers directly to the hub. Patch panels are used to organize patch cables. Specialized Solutions. Token ring cable lengths may be increased by using repeaters. Therefore. but a 4 Mbps card cannot speed up to 16 Mbps.Chapter 5 – Network Protocols & Standards 6 cable has a maximum distance of 46 meters between the computer and the hub.
Since Macintosh builds-in the hardware for LocalTalk in every computer. Apple has always been open to third-party development. Digital Equipment Corporation's VAX™ computers. AppleShare The file server on an AppleTalk network is called AppleShare. A zone is a named Subnetwork that users may access simply by selecting it. mainframe computers. This is useful for expanding the LocalTalk network or for relieving traffic on a larger network. As such. by using zones. Zones LocalTalk networks may be joined together using zones. It will then broadcast the chosen address to determine if any other computer online is using the address. TokenTalk TokenTalk is simply a way to run AppleTalk in a Token Ring (IEEE 802. EtherTalk may be implemented on Thinnet or Thicknet coaxial cable. . The TokenTalk NB card is used to attach to a Token Ring network. so it is not used as often as Ethernet or Token Ring. If it is not being used by another computer.5 Standard) environment. and even some UNIX computers. Inc. LocalTalk performance is rather limited.Network + Training & Test Preparation Guide AppleTalk networks are usually called LocalTalk. the device assigns itself an address. EtherTalk EtherTalk is simply a way to run AppleTalk on coaxial cable using an EtherTalk NB NIC. AppleTalk can incorporate other types of networks such as Token Rings. it is very inexpensive to initiate. it will store it to use each time it goes online. The client software for AppleShare is also included in the Apple operating system. UTP. LocalTalk LocalTalk uses STP. 130 Specialized Solutions. It uses the CSMA/CD access method and can connect a maximum of 32 devices. This address is chosen at random from a range of available addresses. When a computer goes online in a LocalTalk network. AppleShare also provides a print server. or Fiber-Optic cable in a Bus topology. AppleTalk can be used by non-Macintosh computers such as IBM compatible computers.
Inc. These hubs may be passive. ARCNet can use twisted-pair or fiber-optic cabling. It is a simple and inexpensive network architecture that may use a Bus or Star Bus topology. If using either the Star or Bus topology with UTP and RJ-45 or RJ-11 connectors. These packets contain the destination address. or smart. If using an active hub in a Star topology. Specialized Solutions. but it can be adequately charted to the 802.Chapter 5 – Network Protocols & Standards ARCNet ( Attached Resource Computer Network) In 1977 Datapoint Corporation developed the ARCNet technology. ARCNet was developed before the IEEE 802 specifications. The ARCNet Plus architecture can hold up to 4096 bytes of data. but is normally installed using RG-62 A/U coaxial cable. called ARCNet Plus. a token is needed in order for a computer to transmit data. If computer #1 is at one end of the network and Computer #2 is at the other. the source address and up to 508 bytes of data.5 Mbps.4 standards (Token Bus LAN). the maximum cable distance is 244 meters. the maximum cable distance between the computer and the hub is 610 meters. ARCNet utilizes hubs. Obviously. This distance drops to only 305 meters if using the Bus topology. 131 . Instead of the token traveling around a ring. Just like other token-passing access method architectures. the token is passed in numerical order. active. the token still passes in numerical order. has a data transmission rate of 20 Mbps. with coaxial cable and BNC connectors. this can really slow a network down if the computers are not in order. It uses a token-passing access method that transmits at 2. A later version. ARCNet transmits data in packets.
Interference can be lessened by their ability to function in their own band (in the GHz range.11 is the latest generation of enterprise-class wireless LAN technology. .Network + Training & Test Preparation Guide Wireless (802. The capacity to use wireless technology is there for large-scale deployments as well. 132 Specialized Solutions. generally). Inc. Wireless technology is discussed in further detail in chapter four.11) IEEE 802. Speeds up to 54 Mbps will be available within wireless networks (LANs to be more specific).
Packets consist of three components: the Header. Most packets also include error checking or CRC (Cyclical Redundancy Check) methods to check the reliability of the packets received. The 100 Mbps and Gigabit Ethernet architectures will be even more prevalent in the future. the source and destination addresses. and the Trailer. It is extremely important that you understand the different cabling schemes and their connectors as well as the maximum segment lengths for all of these different architectures. Be sure that you understand how this architecture works. but as a networking professional you will encounter them. If it were sent out in one continuous stream it would quickly bring network traffic to a halt due to the large size of the data. Packets will include information to identify the source address. If you are having trouble with any of these concepts. which includes an alert signal that a computer is transmitting. it is still a common architecture and is said to be increasing its market share by as much as 20% per year. Token Passing and Demand Priority) is the governor of how traffic is controlled on a network. Be sure to complete the following exercises and review questions. and clocking information.3 standards. and the access method (such as CSMA/CD. Data is sent out on the network in smaller chunks of data called packets (or frames). It is important for the networking professional to understand the characteristics of each access method. etc. 10Base5. Although Token Ring is not as popular as Ethernet. Therefore. It is important that you understand their specifications and access methods as well. go back and review the chapter again.Chapter 5 – Network Protocols & Standards Summary This has been another information intensive chapter and we covered a lot of information on the different networking architectures. Specialized Solutions. which is where the error checking calculation is located. it is important that you are knowledgeable about the different types of Ethernet such as 10Base2. 133 . the Data. CSMA/CA. AppleTalk and ARCNet architectures may be used less than Ethernet or Token Ring. The popular Ethernet architecture is defined in the IEEE 802. as well as the different cabling schemes and cable distances. destination address and the actual data that is being transmitted. As a networking professional you will encounter this type of network most often. and 10BaseT. Inc. Managing network data is all about traffic control.
Hint: There's a glossary in the back of this book. Keyword Access Method AppleShare AppleTalk ARCNet Beaconing CRC CSMA/CA CSMA/CD Demand Priority Ethernet EtherTalk Frames Header Hub LocalTalk Multistation Access Unit Packets Patch Cable Smart Multistation Access Unit Token Passing Definition 134 Specialized Solutions.Network + Training & Test Preparation Guide KEYWORDS Exercise Define each of the following keywords. . Inc.
Inc. 135 .Chapter 5 – Network Protocols & Standards Keyword Token Ring TokenTalk Trailer Zones Definition Specialized Solutions.
. 5. CSMA/CD and CSMA/CA. What is the maximum segment length in 10Base2? 11.Network + Training & Test Preparation Guide Review Questions Chapter 5 1. Describe the difference between the two different contention methods. 3. Inc. What happens if two computers using the demand priority access method transmit at exactly the same time? 6. What sort of information do packet headers contain? 9. What is CRC and what part of the packet is it usually located in? 8. Describe how data is transmitted in the Token Ring architecture. What type of cable is used in 10BaseFL? 136 Specialized Solutions. What type of connectors are used in 10Base5? 12. How is data transmitted over the network cable? 7. What does the "T" in 10BaseT indicate? 10. Why isn't token passing considered a contention method? 4. What are the three primary access methods? 2.
Name the two main 100 Mbps Ethernet Standards. How are data collisions avoided in the Token Ring architecture? 18. What are the two transmission speeds of Token Ring? 17. How does data flow in an ARCNet network? Specialized Solutions. 137 . 14. What type of access method does an ARCNet network utilize? 25. What is a SMAU? 21. Inc. What is the purpose of AppleShare? 24. Which IEEE Specification defines Ethernet? 15. Which IEEE Specification defines Token Ring? 16.Chapter 5 – Network Protocols & Standards 13. Which way does data travel in a Token Ring network? 20. How does a computer on a LocalTalk network obtain its address? 23. 19. 22. Describe beaconing as it applies to Token Ring architecture. Describe a MIC connector.
.Network + Training & Test Preparation Guide 138 Specialized Solutions. Inc.
in many cases. Starting a Network Project A unique opportunity for any network professional is to design a network from beginning to end. The place to start a new network is with a pad of paper and a pencil or two. The facility – how big is the building(s) and what is the layout of the various offices? Current level of technology – how many computers do they have. Most importantly. Finally. rather than a client's. There are two things that you will need to know. Hardware compatibility is a major consideration in network design and is often the source of troubles when expanding or upgrading networks. For most of us this will be a rare event since most companies already have a network and are working with expanding or increasing the performance of what they already have. This is especially true if you will be maintaining or upgrading this network in the future. However. As a network professional. you need to approach the project as if it were for someone else. for example. this is a Macintosh-based company.Chapter 6 – Network Design Chapter 6 – Network Design In this chapter we are going to put to use many of the terms and concepts that we studied in earlier chapters of this training guide. (If not. who has them. but if your customer is a Macintosh user. you certainly don't want to design a network around Windows. and goals. Then we will study in more detail network adapter cards. This is well and good if you are designing a network for your own use. we will consider hardware compatibility. whoever is assigned the upgrade project will be forever indebted to you. The most important aspect of creating a new network is to document everything that you do. This will give you the discipline to ask yourself the right questions and to begin the process of documentation. We will start by looking at what it takes to layout a network from scratch. Inc. The size of the company and the portion of the network affected. pay attention to details. (demographics). are there any printers or scanners. The customer's likes. The product – this is very important as a graphic arts client will have different needs than an engineering firm or a law office. The following is some suggested information that you should gather about your customer: The basics – name. The Customer Obtaining a clear understanding of your customer and their needs is essential when designing a network. you will have a lot of knowledge and expertise with networks. etc. Specialized Solutions. you are not designing for yourself. how they are installed and how to troubleshoot them. your design will not work for them. etc? If. dislikes. address. You could design the best high-speed low-cost Windows system that was ever imagined. Even if this network is your own. 139 .
Once you collect this information. only documenting the facility and the requirements of the network. There are many intermediate drawing packages that are available. prepare a design document. This can be done using any word processor or spreadsheet program. You will need this information as you make decisions in the next few steps. a textonly MS Word file will be approximately 30 KB of data while a single page image file will average 50 KB. if the file is compressed. You may want to consider using a drawing program to create a layout of the facility. you are now ready to begin the designing of the network. or as large as 8 GB. or as complex and as expensive as AutoCAD.Network + Training & Test Preparation Guide The Network Goals In addition to the customer's needs. or as much as 8 MB for the same image scanned (black and white) at 300 dpi uncompressed (even more if color or grayscale). the same 1000 documents could be as little as 30 MB. etc. print services. For example. This can be a simple program like Microsoft Paint. Your document should include a summary of all the information you collected. at this time. . Is an Internet connection needed now or in the future? Will it be for all users or just a select few? What additional services will the network need to provide? Sharing of resources. 140 Specialized Solutions. With this information in hand. The following are some questions to consider: Will this be a simple LAN or a complex WAN with Internet and remote users? What are the future needs? Is this network to start small and expand later. files services. you are not documenting your network. or will it meet the requirements of the latest technology? How much traffic do you anticipate now and in the future? A business office moving 1000 documents and spreadsheets across a network will generate far less traffic than a graphic arts or engineering office moving 1000 large imaging files. Inc. Remember. A good intermediate program is Visio 2002. This program provides simple templates for both facilities and network components. you must get a clear definition of goals of the network. So.
Inc.Chapter 6 – Network Design Specialized Solutions. 141 .
They can provide services to the network and use services provided by others. The first is the type of network you will be designing. but most operating systems like Windows 95 and up and Macintosh OS X are "network ready. The following lists the information that you will need in order to choose your network type. Also. For example. The number of nodes (computers and other resources) on the network. you can share it to the network and anyone who has access to the network can send work to it. you will need to start making some decisions. The commitment of management and users. Are they able to handle a sophisticated network or must the network be transparent to them? The available budget (both now and in the future). Most personal computers today will have more than enough power to successfully operate in a peer-to-peer environment. You may have to add network cards and cabling. all computers are equal. Keep in mind that you may not be able to mix two different operating systems without additional software or upgrading to a client/server network. In a peer-to-peer network. if a colleague has a color printer and you don't. as generally it is not installed during a standard installation. Here you will have two choices: peer-to-peer or client/server. The level of security required. The type of business and how that will affect network traffic. not all nodes may need the same level of security." That is. Skill level of the network users. You may need to install the software. you will have no problem. Are they committed to the change or are they going to resist the change? When to Choose Peer-to-Peer There are many reasons why you would want to choose peer-to-peer. If you do not have this information go back and get it. The decision that you make at this time will have an affect on the hardware and software choices that you make in the future. This means that every 142 Specialized Solutions. The disadvantages of peer-to-peer networks are security and limited network size. Peerto-peer networks do provide some security in the form of allowing you to select what you want to share to the network. You will need to take careful consideration of the information collected in the first step to assist you with this decision. Peer-to-peer networks are economical to setup and implement. Inc. Likewise.Network + Training & Test Preparation Guide Determine Network Type Once you collect all the information described above. First. The wrong choice now. As long as you have the original software disk (CD). you can send work to it if you need color printing (assuming that they share the printer to the network). This sharing is on a directory level. This can range from none to very high. may cause problems in the future. . The most prominent are simplicity and cost. they do not require a high-power computer with lots of speed and processing power. if you have a printer connected to your computer. they include the necessary software and protocols for file and print sharing.
administration can be a Specialized Solutions. etc. Before you can use any resource. For these people. Remember. 143 . any user can log on to a workstation (with a new name and password) and gain access to the network. but what is often overlooked is the cost to administer the network. As for size. This will be especially true if your workstation is using an older. The most prominent disadvantage is the cost to install and operate the network. you must have both the authorization to use the network and permission to use the resource. You can connect more workstations. These server-based networks provide a central database that manages access to all the resources as well as the network itself. you will not need to worry if Mary is on vacation and her computer is turned off (since she is the only one in the company that has a color printer). In a server-based network. must less the workings of a network.Chapter 6 – Network Design file in the directory will be available to the network. The result will be a slow-down of performance on your workstation. In a small network where everybody knows each other and security is not an issue. Inc. you will also need to consider the disadvantages. In a peer-to-peer situation. While there are many advantages. but there will most likely be reductions in network performance as stations are added. they will also be using your processor to do their printing. Using a file server to maintain all of the company-wide files. and lots of memory. This means that one or more computers are designated as servers and provide the resources for the entire network. a client with a limited budget may consider this type of network as a starting point or entry-level network. such as your printer. server-based networks are scaleable. instead of backing up individual workstations. the more knowledgeable the administrator needs to be. if employees need remote access. Also. information can be made available to them through a RAS (Remote Access Server) connection. Since these computers are larger. a peer-to-peer network may be the perfect solution. When to Choose Client/Server On a client/server network (also known as server-based networks). In large networks. this will take part of their normal workday will be taken up to react to any problems and maintain existing accounts. The more sophisticated the network. Another advantage of server-based networks is that the servers are never turned off. and expand as your needs expand. Most employees have little or no knowledge of the workings of computers. slower processor and/or has limited memory (RAM). It is obvious that server-based networks will require better and higher-powered hardware. if anyone is using a resource on your workstation. only a network administrator can create a user name and assign permissions to that user. This means that if you need to use the color printer that is connected to the print server. Perhaps the most significant aspect of using server-based networks is security. This centralized file system also makes for easy transfers of files throughout the company. is another advantage of a server-based network. 24-hours per day. In a strict peer-topeer network. the network must operate transparent to them. Last but not least. the general rule is that peer-to-peer networks should be limited to about 10 workstations. This means that you can start small with one server and a few workstations. the performance of the network will be better than in a peer-to-peer network. all that is needed is one or two knowledgeable people to act as administrators. all network resources are usually centralized. Also. In small networks. have high-power processor.
For this reason. let us define the difference between the terms public and private network.0 -10.0 144 Specialized Solutions. it is highly recommended that you use these addresses for your private addressing. 10. Public and Private networks In addition.0.255. with open access to the global community.255 255. The only problem is that if your firewall were to come down.0 192. A private network would be a corporate network or an Intranet. The use of these addresses will completely prevent the address conflict issue. This decision will be the basis for the rest of your network design.255 172.0. When you are sitting on the fence. since your organization will more than likely need access to the Internet and networks outside of their LAN.255. Making the Choice Making that final decision is often difficult.0 255. .0 .255.192. you can use any address that you want to use inside of your own network and behind your firewalls.0 255. then you might have an address conflict with another entity on the Internet.0.0 -172. which would limit its access to those outside of the company.0. the answer will be very obvious. in others it could go either way. If you are not sure you have enough information. stick with it and move forward.16.168. Each network operating system supplier has their own certification program such as Microsoft's MCSE (Microsoft Certified System Engineer) and Novell's CNE (Certified Novell Engineer). Once you have made this decision. Inc. be sure to follow a disciplined procedure: Collect all your information. get more.Network + Training & Test Preparation Guide full-time job for one or more people and may even require the skills of a certified network professional. Actually. present each case to the client and let them make the final decision.32. Prepare a case (on paper) of the pros and cons of each.0. If all else fails.255. A public network would be the Internet.0. there are specific addresses that are filtered by the routers at the backbone of the Internet.0. In some cases. For this reason.255.0.255.168.
Chapter 6 – Network Design Specialized Solutions. 145 . Inc.
Remember. On the other hand. Inc. don't just simply ask someone what he or she has. You may also want to take an inventory as part of your initial evaluation. The documenting of existing equipment includes two components: hardware and software. you can skip this section. 146 Specialized Solutions.Network + Training & Test Preparation Guide Define the Starting Place If you are designing a network from the ground up and literally starting with a blank piece of paper. When taking this inventory. The best approach is to make an inventory sheet for each piece of equipment. The following is an example of an inventory sheet. use this sheet to define your proposed new equipment. That person is you! Be sure to take a small toolkit and a flashlight with you. whether hardware or software. Some of the information you need may be inside the machine and you will have to remove a case or two. if you are creating a new network and have no inventory to work with. Feel free to use this as a starting place for developing your own customized form. . if all or part of a network already exists. you must add new hardware. Use it as a starting place to build your own. this is a detailed inventory that requires someone that is knowledgeable in computers and networks. Also. you will need to make a detailed inventory of the materials you already have. This form should identify the equipment and its specifications. ask him or her to show you. The following page shows an example of what an inventory sheet might look like.
147 .) # of Free Slots Network Card Printer: Installed RAM Interface (Parallel or SCSI) Network Compliant (Yes/No) Peripheral: Type of Device Interface (Parallel or SCSI) Specialized Solutions. Inc. PCI. etc.Chapter 6 – Network Design Network Equipment Inventory Sheet Item Number: ___________ Type of Equipment: Computer Printer Telecommunication Other If Other: _______________________________________ Location: Identification: Make: Model: Serial #: ____________________________ ____________________________ _____________________________ ____________________ ____________________ ____________________ ____________________ ____________________ ____________________ ____________________ ____________________ ____________________ ____________________ ____________________ ____________________ ____________________ ____________________ ____________________ Computer: Processor (Type and Speed) RAM Hard Drive(s) Monitor Video Card Modem Connected Peripherals Bus Type (ISA.
148 Specialized Solutions. describe each program. Software: If this device uses software. Inc. . Name of Program:(Operating System) __________________ Version Number: Licensing Information: ____________________ ____________________ ____________________ Original Disk (CD) Available: ____________________ Name of Program: Version Number: Licensing Information: ____________________ ____________________ ____________________ ____________________ Original Disk (CD) Available: ____________________ Name of Program: Version Number: Licensing Information: ____________________ ____________________ ____________________ ____________________ Original Disk (CD) Available: ____________________ Use additional paper if necessary.Network + Training & Test Preparation Guide Telecommunication: Describe the device and its function.
149 . Inc.Chapter 6 – Network Design Specialized Solutions.
By assigning them a number now. it will make future documentation easier. This might be a good time to start identifying each node with a name and number. Inc. It is time to get out that pencil and paper. or the software drawing program that you used to create the layout of the facility. . make a drawing of the facility and each network node. Using the inventory sheets and the objectives of the network. and collect all of the documentation you have been working on.Network + Training & Test Preparation Guide Design the Network At last we should have enough information to start designing our network. Start with the location of existing equipment (if any) then draw the location of the new equipment. A Network Layout 150 Specialized Solutions.
but if this is a large facility. However. repeaters and nodes. In addition. However. It will cost a lot more to upgrade later. It may be more cost effective to purchase a large quantity of plenum grade rather than a mix of plenum and standard grade. or hub to computer) does not exceed 100 meters (328 feet). The most important aspect of media selection is to be sure that the media you choose will meet the performance criteria of the network. or just good common sense.Chapter 6 – Network Design Media Selection Media selection is an aspect of installing a network that should not be taken lightly. you will need to install CAT 5e or CAT 6 UTP to be able to take advantage of its 1000 Mbps speed. If you intend to use UTP or STP cables. hub location is critical for determining cable lengths. The following are several other factors that must be considered before making your final choice: Topology – If you use a physical star topology. 151 . such as in an imaging environment. you must comply with requirements of the 5-4-3 rule for number of segments. a small network with only a few workstations sharing files and printing will probably work fine with CAT 5 UTP cables. Therefore. On the high end. If economics are a major concern and you are designing a small temporary LAN. (up to 2 kilometers – 6562 feet) choose fiber optics. the cost of CAT 5 is not significantly more than CAT 3. For example. you might consider CAT 3. if you are not sure if expansion is in your future. you will need Thicknet coaxial cables. Cable lengths must be considered. if you are going to have hundreds of computers or transfer large quantities of large files. It is the most labor-intensive of all the processes and the most costly to replace. you will need to remember that all cables must originate from the hub. consider Thinnet coaxial cable. you must make sure that the longest connection (computer to computer. where money is no object and security is critical or you have long distances to cover. Inc. These cables are inexpensive and if all computers are in the same proximity. and the run from the server room to the maintenance shop is 400 meters (1312 feet). 5-4-3 – If your installation is coaxial Ethernet. Cable Grade – Local fire codes. Specialized Solutions. The 100 Mbps speed of this media will handle this workload without problems. it would be worthwhile to spend a little more now and install CAT 5e or CAT 6 than to replace it in 2 to 3 years. Realistically. CAT 6 is the UTP of choice. a simple bus topology with each computer in a series will save on the budget (don't forget to terminate each end). may require that you install plenum grade cables for part or all of your installation. In most environments this will be no problem. Cable Type – If your goal is to save money now and you don't need a high-speed network. for long term use and eventual upgrade to 100 MHz.
Fortunately. such as NetBEUI are simple and work well with peer-to-peer networks and small LANs. EMI. Protocol Selection The most important issue with selecting a protocol is to use the same protocol throughout the network. It is not strictly necessary to have a dedicated room for the equipment. which requires the use of routers. since they don't use electricity to transmit a signal. which can generate damaging ESD. Like us. you may need to install fiber optics at least in that area. The next choice is whether to use a routable or non-routable protocol. are usually what is found in the office environment where most networks are installed. the same conditions that are good for people are often ideal for computers. The non-routable protocols. or uses lots of electrical or electronic equipment that generates EMI (electromagnetic interference) or RFI (Radio Frequency Interference). but are not limited. and this is also the ultimate atmosphere for a computer. low-humidity. Environmental Concerns A major concern that is often overlooked when designing a network is the actual environment in which the computers will be operating. Most network operating systems today are robust and will operate transparent to the users. high-humidity. which is kept at the ideal temperature for the equipment. can all cause a computer to fail or behave erratically. Inc. and RFI. which can cause corrosion. Less than ideal conditions will also decrease the life expectancy of your equipment. such as a surge suppressor and an uninterruptible power supply. Fiber optics are also a good alternative when the manufacturing environment cannot allow for any possibility of even a small spark. . The equipment should be shielded from ESD.Network + Training & Test Preparation Guide Noise – If all or part of the installation is located in an industrial environment (vibration and noise). 152 Specialized Solutions. but it is important that the room be well ventilated and climate controlled. on the surface. it may not be prudent to recommend the change to Windows 2000/2003. and should have a method to ensure that clean power is available. Therefore. Environment – If all or part of the network is in a hostile environment (corrosive manufacturing) you should consider alternatives like fiber optics. Most larger companies will have a dedicated room for their server (the Server room). you need a routable protocol such as TCP/IP. As long as it is configured well and meets the needs of the customer. If the customer has always used Novell NetWare and is satisfied with the performance. Constant temperatures of around 70° F. if you intend to work with a larger network or WAN. it doesn't really matter. Variable temperatures. However. they are sensitive to temperature changes. NOS Selection Choosing the network operating system is a matter of user preference. with a relative humidity of 30 percent. sometimes the customer will make the choice for you. On the other hand. and fluctuating line-voltages from the incoming power source. it will work. These routable protocols are more difficult to configure.
Inc.Chapter 6 – Network Design Specialized Solutions. 153 .
This way you can identify each location. Connecting to a computer Cable to Hub The connection of the cables to the hub will usually take place in the "server room. This way. you will most likely need to install a wall outlet. the cables are connected to a patch panel. In most cases. The type of outlet will depend on the type of cable. To keep these organized. One thing to remember about these patch cables is that their length must be considered as part of the overall length of the cable. There are a few more components that need to be installed.Network + Training & Test Preparation Guide Putting it all together Installing the media is a task that is often best left to someone who specializes in cable installation. it will be a wall plate with an RJ-45 outlet. The hub will know that the cable is not connected and will simply ignore it. . Each cable is in turn connected to one of the outlets and a patch cable is then used to connect it to the hub. Inc. Cable to Computer Depending on the selection of cable. This is just a strip of RG-45 connectors. 154 Specialized Solutions. These outlets will make for a nice and neat installation and will make the room ready to connect a computer to the network. So let's assume that you or your specialist has run all the cables. One advantage of using CAT 5 or CAT 6 cable in a star topology from a hub. Make sure that either you or the specialist marks each cable at both ends. All the cables will be brought to one location. is that you do not have to install a computer on every outlet." This is a centrally located room or closet that will house the primary server and hub. you can install future or optional locations in preparation for expanding. if using CAT 5 or CAT 6. The next step will be a patch cable that runs between the network adapter card and the outlet.
Once that is done. there are three things to consider: • • • Network Compatibility Media Compatibility Computer Compatibility Connecting to a NIC Specialized Solutions. there is one more part of the Physical layer that must be installed. Because it must connect to both the computer and the media.Chapter 6 – Network Design Connecting to a Hub Network Adapter Cards Installing the cabling for a network is literally installing the Physical layer of the network. This card is a circuit board with all the electronic circuitry and components necessary to physically connect to the computer and the media. Therefore you must know the requirements of each. Actually. That part is the network adapter card. Inc. 155 . we must select a card that is compatible with both.
Network + Training & Test Preparation Guide 156 Specialized Solutions. . Inc.
but only at 10 Mbps. Note: Laptops and proprietary computers will have special cards designed to fit their architecture. Card to Network Network adapter card compatibility is simple. In addition to being compatible with the network. This bus is a group of parallel conductors that carry digital information to and from the CPU to all parts of the computer. and PCI). Making incompatible components work together is possible in most instances. also called PC Cards. will change. This section will look at compatibility issues.Chapter 6 – Network Design Network and Hardware Compatibility Network compatibility is a key consideration in network design. 157 . but requires some knowledge of the inside workings of a computer. but in the long run this will add significantly to the cost and time requirements of maintenance. Adapter Card Compatibility A network card acts as the interface between the computer and the network. If you are installing a Token Ring network. Some network cards provide diagnostic lights. The best way to find out is to remove the case and look. For example. the number of connectors. Some of the newer 100BaseTX cards will work on a 10BaseT network. These are little LEDs (one. Micro Channel. administration. there are compatibility issues on both sides of the interface. and therefore the speed at which data can be moved. the speed of the card is important. Before purchasing a network card. EISA. a Specialized Solutions. Network cards are designed to meet the standards of the bus. which can be a useful tool. so you will have to check the documentation to be sure of their meaning. In general. Inc. you must have Token Ring cards. Laptops generally use PCMCIA cards. The processor (CPU) in a computer will communicate with the expansion cards through the expansion bus. Also. you will have to know the type of expansion slots used in the computer and whether or not there are any free slots. An Ethernet card simply won't work on a Token Ring network. a 10 Mbps card (10BaseT) will work on a 100 Mbps network (100BaseTX). Resolving these issues is actually quite simple. and expansion projects. two. The adapter card (NIC) must be able to communicate on the network using the same standards and protocols as the other components. Depending on the vintage of the computer. Building across-theboard compatibility for hardware and software at the design stage will simplify future maintenance and troubleshooting. the card must be compatible with the computer. The different types of cards are designated by the orientation and number of these connections. There are four types of cards that you will encounter (ISA. Not all cards are the same. or three) that indicate the status of the card. On one side of the circuit card are a group of gold "fingers" that fit into the slot to provide the electrical connection. Therefore. The actual connection between the card and the bus is called an expansion slot because of the way the cards are installed. but only at 10 Mbps.
Note: Many computers that are designated as servers or gateways can have more than one network card installed. if you upgrade your operating system. Connect the network cabling. You need to configure the card to work with your network software. be sure that no other device has already been assigned the IRQ or I/O address. Inc. In addition. Understanding the installation process is the key to preventing conflicts. Hint: you may not want to put the case back on until you have confirmed that the card is working. 158 Specialized Solutions. If there are any conflicts. it only means that the proper connection has been established between the card and the network. In most cases with a new card. Now the network adapter card is installed. the computer may not boot or the conflicting devices might not be able to work simultaneously. The details of installation will vary depending on the type of computer and the operating system installed. Drivers are usually supplied with the network card. but you are not finished yet. Card and Computer Installing a network adapter card is not any different than installing any other expansion card in a computer. Install the appropriate drivers for the card. Note: If you must remove the case. be sure to follow ESD (electro-static discharge) procedures. the following is a generic procedure that defines the key points that you must follow: Purchase the card. You still need to bind the card to the network protocols that you are going to use. Finally. Each card must be configured for a different network. If your system is not Plug-n-Play. you can usually download them from the manufacturer's web site. If you must do this manually. Remove the case and install it into a free expansion slot. . Many operating systems already include drivers for most network cards. you may need to download a new driver in order to make it work or to increase its performance. you will need to check the documentation for the network operating system that you are using. Configure the IRQ and I/O address. you may still have to manually set some jumpers or switches.Network + Training & Test Preparation Guide green light indicates that a proper network connection exists and a flashing yellow light indicates that data is being transferred. If you don't have the driver or want to make sure that you have the latest driver. Keep in mind that a green light does not mean that the computer is properly configured and you can use the network. Since describing the installation of a network adapter card for every system is beyond the scope of this training course. Physically install the card. First ensure that it is compatible with your system (network and computer). this will be done with the installation software or by the operating system.
the decision may end up with the company's management and you will have to work with it. Inc. the card should have an RJ-45 connector. AppleTalk employs a DIN-type connector and IBM Token Ring uses a DB-9 connector. 159 . it is your responsibility to point out the strengths and weaknesses of each scenario. and the administrative department may just be thankful for having whatever they could get their hands on. In the case of UTP. To increase marketability of their cards. the graphics arts department may be Macintosh-based. some manufacturers will provide two. different connectors allowing for multiple installation scenarios. Many growing companies purchase their computers only as needed and will select the best buy of the day. A typical problem encountered with highly departmentalized companies is that each department has its own preferences. For example. The bottom line is to be sure to look before you buy. Computer Compatibility Computer compatibility is often a serious problem encountered when installing a network in an existing facility. If you encounter this type of situation. the engineering department may be PC-based. as well as possible solutions. the card must have a coaxial BNC connector. These types of problems can be more personal in nature. and possibly three. However.Chapter 6 – Network Design Media Compatibility Media compatibility is the ability of the cabling to physically connect to the card. For Thinnet or Thicknet. You may have to connect some older "legacy" hardware with some new high-speed high-tech machines. While this makes good sense to the accounting department. it can create havoc when you have to connect them and actually have them communicate. Some STP cards require special connectors. For example. Specialized Solutions. as some individuals will not want to change their way of doing things just to have a network.
and knowledge of the network operating system. You will also need to know the type of processor and the type and number of available expansion slots. hard work and standards.Network + Training & Test Preparation Guide Preventing Compatibility Problems There are really only two methods of resolving compatibility issues. As long as the system is designed to meet the same standards. . Your only recourse is to document every computer and piece of hardware that must be connected to the network. that were identically configured. each component will work with the others. With this information in hand. you will need to establish the standards for your network. and detail both its hardware and software. Inc. Standards Earlier in this training course. if installed. you are going to have your work cut out for you. with identical computers that were purchased from the same supplier. As the network designer or administrator. you will be assured that any new additions will function properly. Unless you are very lucky and are installing a new network. you should be able to predict potential hardware compatibility problems and take action to prevent them. boot up each computer and note the operating system and any installed software. 160 Specialized Solutions. Standards are one way in which hardware and software suppliers can develop a product and be assured that it will work with the products of other suppliers. we learned about network protocols and standards. By defining the standards to which the network must comply. This will most likely require that you remove covers and identify components such as the modem and the network card. Hard Work Hard work and attention to detail are your only allies when it comes to setting up a network from an existing system. With this done.
the system will not run. you will be able to locate and download them from the manufacturer's web site. but your proficiency will be very low. Also. Most manufacturers will also publish suggested minimum requirements.Chapter 6 – Network Design Resolving Compatibility Problems No matter how careful you are. Microsoft says that you do not need a mouse to run this operating system. In this case. If drivers exist. These requirements by no means indicate what you should purchase. A good example is Windows 95. These will be somewhat higher than the required minimum and are what you need to operate the system at a normal performance rate. Most hardware compatibility problems are resolved by installing the latest drivers. when upgrading from Windows 98 to Windows XP. you will need to check the manufacturer's recommendations for the minimum requirements to operate. More than likely. These are the bare minimum requirements to run the system. The networking industry is in a constant state of change and unless you want to be left behind. the Internet is the answer. Drivers for a particular device are not always available for all operating systems. If the operating system was released after you purchased the device. you find that your modem. Minimum Requirements When evaluating or considering an upgrade or change of an operating system. Specialized Solutions. all you need to do is install the Windows XP drivers for the offending hardware. The first thing you need to do is determine if the original disks/CD that came with the device has the drivers to match the new operating system. Some devices do not have drivers for all operating systems. 161 . you will need to upgrade. You should always confirm the availability of drivers before purchasing an unknown device. network card and/or printer no longer work. This is a true statement. Inc. there are several web sites that specialize in downloading drivers. only that if you don't meet these requirements. The later Windows operating systems require a mouse as one of the minimum requirements. you probably do not have the necessary drivers. have you ever tried it? You can run Windows 95 without a mouse by using only keystrokes. however. For example. sooner or later you will encounter compatibility problems.
microsoft.com/windows/catalog. Microsoft Windows Catalog Still another web site to check for compatibility of hardware and software. It is considered an advanced operating system and will not work with all hardware. This list will ship with the 2000 package (on the CD-ROM) and 2000 will make a check during installation. is the Microsoft Windows Catalog at www. You can also look for the corresponding logos on the boxes of hardware and software that you are considering purchasing for your network. If you were to purchase an econo-version of a computer or one that is highly proprietary.Network + Training & Test Preparation Guide The following table lists an example of the minimum requirements for three operating systems: HCL and Windows 2000 To help alleviate compatibility issues some manufacturers provide HCLs. . you will need to check the HCL for that product. or to confirm whether or not your existing hardware will work with Windows 2000. An operating system such as Microsoft Windows 2000 is hardware dependent. or hardware compatibility lists. 162 Specialized Solutions. To assist in making an informed purchasing decision. Here you will find the latest information about hardware and software that is Designed for Windows XP and Windows Server 2003 or at least tested to be compatible with these operating systems. you can get it from one of Microsoft's web sites. If you want the latest list. it most likely will not work with Windows 2000. especially with the newest operating systems such as Windows XP and Windows Server 2003. This is part of the Windows Logo program. Inc.
Inc.Chapter 6 – Network Design Specialized Solutions. 163 .
What are the two most prominent reasons to choose a peer-to-peer network? 4. Was this a good purchase? 9.Network + Training & Test Preparation Guide Review Questions Chapter 6 1. However. . Your accounting office found a really good deal on network cards. What are the two areas of concern when starting a network project? 3. but they are not all the same. 7. What is the number one reason for choosing a client/server network? 5. Your client is installing a small Ethernet network and trying to save money at the same time. How do you know if a new piece of hardware will work with Windows XP? 164 Specialized Solutions. Your company just bought ten new computers and all are guaranteed to meet the minimum requirements of Windows XP. You are expanding your network and will need to invest in 50 to 100 new network cards. Why should you refuse this offer? 8. What are the two tools required to initiate a network design? 2. Give one reason why you should recommend that he spend a little more now and install CAT 6 cabling instead of CAT 5. Is NetBEUI a good protocol to use with a large WAN? 6. he intends to expand the network in the future. Inc.
Specialized Solutions. An active hub will require power and will often provide some form of signal conditioning (amplifies weak signals). you cannot use an Ethernet hub on a Token Ring network. Inc. In addition to being called "hubs.Chapter 7 – Expanding a Network Chapter 7 . sooner or later. to larger hubs that can connect many more computers. This chapter will discuss several techniques for expanding a network. Passive hubs do not use external power and are used only to concentrate the cables in a common location. from simple five-connector hubs used to connect five devices. A hub is a device that acts like the central station for all computers on the network. Active hubs can be used to extend the length of network cabling by connecting them in a series. For example.Expanding a Network No matter how well you design a network. 165 . it may be too small. There are several different types of hubs. Expanding a LAN with Hubs A common method for expanding networks is to use a hub." you may also hear them referred to as: • • • • Concentrators MAU or MSAU– Multistation Access Unit (Token Ring) Patch Panel SMAU – a Smart MAU Hubs can be either active or passive.
They do not translate or filter any information. Each has its own unique advantages and disadvantages. thereby compensating for signal loss due to long cable lengths. 166 Specialized Solutions. Inc. the simple hub just won't do the job. such as databases. Depending on the objectives of the LAN. Repeaters A repeater is a device that is used to extend the cable length on a network. amplify the signal. When the time comes to make a serious expansion to a LAN. have increased response times. Fortunately. you will have to employ one or more different pieces of hardware. Repeaters work in the Physical Layer of the OSI model. A bridge can be used to isolate segments on a LAN. You are just plain tired of your old system and want to get your system updated. there are several other devices that can be used to expand a network. Traffic-generating applications. Repeater Bridges A bridge does the same things as a repeater. but has one additional feature. Long waits to access a printer or file. thus reducing the traffic for each segment.Network + Training & Test Preparation Guide When a LAN is Too Small There are several reasons to consider expanding a LAN: • • • • Too much network traffic. They do however. Bridges work in the Data Link Layer of the OSI model. .
It is an entrance to another network that controls traffic on your network.Chapter 7 – Expanding a Network Bridge Routers A router has all of the features of a bridge. Routers can also determine the best path for "routing" traffic and filter broadcast traffic on the local segment. 167 . but it can switch packets across multiple networks. Think of a gateway as a computer that acts as a translator between two networks that don't speak the same language. Inc. Router Gateway Gateways make it possible to connect different network architectures. Routers work at the Network layer of the OSI model. Not all network protocols will work with a router. the NetBEUI protocol is not routable. Specialized Solutions. For example.
but connecting at this rate is rare. and satellite connections. An example of such a system is the telephone company. These are our standard telephone connections. Be careful when choosing a carrier. They are providing the cabling. and the cost of the service. . Keep in mind that there are many carrier companies that provide many different services at a variety of rates. The first is public dial-up network lines. lines. there are two levels of service to consider. or dedicated. Carriers Carriers are the companies that we contract with to carry our data over long distances. When thinking of telephone lines. does not mean that it is the best value. Some of the newer digital services will claim to have a speed of 56 Kbps. we most commonly think of our local telephone company or one of the long distance carriers. microwave. When thinking of a carrier. each computer must use a modem and establish a direct connection. Typically. the distance the data must travel.Network + Training & Test Preparation Guide Gateway Connection Services When expanding a network beyond the local area cable boundaries. Be sure to compare them on an equal basis and look for hidden costs. When considering which connection service to use. these connections are slow and not very reliable. With dial-up networking. The second choice is leased. 168 Specialized Solutions. it is likely that you will need to connect to a third party's cabling system. Just because the cost looks good. Speed for leased lines can reach 45 Mbps. be sure to take into account your throughput. These powerful full-time dedicated connections do not use a series of switches to complete the connection. Inc.
and deals with timing issues. Inc. You can also use ISDN adapters if you are using ISDN PRI for WAN connectivity. The DSU is responsible for converting both the input and output between the frame types between the LAN and the WAN. Most WANs are a collection of LANs. It also changes the frame type back when frames are sent back. 169 .Chapter 7 – Expanding a Network WAN Overview When the physical capabilities and distance limits of a LAN need to be exceeded. It can regenerate the signal. as well as those transmitted to it. routers and communications services are used to create a WAN. There are two types of PSTN: dial-up lines and dedicated analog lines. if necessary. items such as bridges. The CSU is responsible for both the signals received from the WAN. Communication between LANs will involve one of the following technologies: • • • Analog Digital Packet Switching Analog Connectivity Analog communication is the one that we are most familiar with. A CSU/DSU (Channel Service Unit/Data Service Unit) is a hardware device responsible for changing the frame type from whatever the LAN is using into a frame that will work on the WAN. WAN links can include any of the following: • • • • • Cable Television Coaxial Systems Fiber-Optic Cable Microwave Transmitters Packet Switched Networks Satellite Links Those using a WAN link to connect LANs will need to use CSU/DSUs. It is based on PSTN (Public Switched Telephone Network). These physically larger networks will appear to function the same as a LAN. Specialized Solutions.
Voice and data over private lines.Network + Training & Test Preparation Guide Analog Signal The dial-up lines can be further classified as: Line Type Description 1 2 3 4 5 6 7 8 9 10 Basic voice. but if you have sufficient traffic. they can be justified. Voice with some quality control. more secure line than can be provided by an analog connection. Voice/radio with tone conditioning. Dedicated analog lines provide an instant connection. Digital Connectivity When you need a faster. . Voice and video. Voice and data over trunks between computers. Dedicated lines are far more expensive. Data applications below 1200 bps. The down-side of these lines is that you will have to pay for them 100% of the time instead of on an "as used" basis. you need DDS (Digital Data Service). 170 Specialized Solutions. The primary reason for using digital lines is that they are 99% error-free. This is because you lease the line 100% of the time and therefore do not have to dial-in. Application relays. Basic data. Inc. Voice and data over trunk circuits.
It can be used to transmit digital voice.8 Mbps 155.520 or 622.736 Mbps 2.544 Mbps transmissions.048 Mbps 34.52 Mbps Either 155. data. Inc. Specialized Solutions.Chapter 7 – Expanding a Network Digital Signal T1 is the most widely used type of digital line.368 Mbps Varies depending ISP.080 (can reach 10 Gbps) OC-1 OC-3 ATM 1 3 N/A N/A N/A N/A The T1 and the T3 standard are American. faster download than upload 51. and video signals. whereas the E1 and the E3 are the European standard. It is capable of 1. The following table lists the most common connection types: Connection Type T1 T3 E1 E3 XDSL T1/E1/OC1 Channels 1 28 1 16 N/A Voice Channels DATA RATE (MBPS) 24 672 32 512 N/A 1. 171 .544 Mbps 44.
This made for a very reliable and very slow connection. and reliable network messaging. convenient. each packet was examined at each step in the path to determine whether it was damaged. this particular type of network is not suited for most companies' business needs. A packet switched network provides multiple paths that packets could travel from source to destination. Standard PSTN lines have a very limited bandwidth of less than 56 Kbps. With Frame Relay. In older. Today's networks use a different technology referred to as Frame Relay. Frame Relay does not check the packet at each step in its route. X.Network + Training & Test Preparation Guide Circuit-switched Networks Circuit-switched networks set up a continuous direct connection between the individual calling and the one being called. since the infrastructure of the phone line we use today was created long before the advent of the personal computer and the Internet. These lines can. a packet may be sent over multiple permanent virtual circuits (PVCs). Inc. all of which are considered reliable. . 172 Specialized Solutions.25 based packet switched networks. For this reason. POTS (Plain Old Telephone Service) or the telephone lines are the most common example of this type of network. however. Circuit-switched Network Packet Switching Networks Packet switching is a means of providing fast. so it can be both reliable and fast. Obviously. be used for somewhat secure remote access by employing the use of virtual private networks (VPNs) and tunneling protocols.
Chapter 7 – Expanding a Network Packet Switching VLAN Virtual LANs (VLANs) can be viewed as a group of devices on different physical LAN segments that can communicate with each other as if they were all on the same physical LAN segment. or any other logical means. which lays out hosts (computers.) by another means apart from how they are connected physically and geographically. This type of network is most closely associated with a "campus environment. This allows the administrator the luxury of modifying the VLAN. It is best understood as a "logical" LAN." Specialized Solutions. without having to change the physical picture of the network. etc. Inc. printers. or by the specific use of the computers. 173 . adding computers or adjusting resources. An administrator might set up a VLAN based on certain departments within his company.
These cells can speed communication because the network always know exactly what to expect in regard the size of the next cell. however. Inc.Fiber Distributed Data Interface is the basis of fiber optic communication. it is a good choice for LANs that require large bandwidth and high speeds. in actuality. they currently operate at as high as 622 Mbps with most commercial boards operating at 155 Mbps. However. twisted pair. while using copper telephone wires. or fiber optic. ATM is not media dependent and will operate on coaxial.Asynchronous transfer mode uses fixed length (53 byte) cells instead of packets. ISDN BRI (Basic Rate Interface). which is intended for use in the home or small business. It was designed specifically for Token Ring networks and has a maximum ring length of 100 Kilometers (62 miles). As well as the common voice and data. These systems are designed to operate at a throughput rate of 1.2 Gbps. ISDN Integrated Services Digital Network was one of the early digital services. This means that the choice of media will limit the maximum speed of the network. . has two 64 Kbps 174 Specialized Solutions. It will support 500 computers and run at 100 Mbps. ATM is relatively new and will require special hardware and bandwidth to reach its full potential. ATM . Because it is fiber optic-based. ATM can be used with FAX. audio. While not a good choice for WANs. One of these may just provide you with the necessary bandwidth and speed that you need.Network + Training & Test Preparation Guide VLAN Advanced WAN Environments If the existing services available do not meet the needs of your WAN. video. you might consider some of the advanced WAN technologies. and imaging. FDDI . it will provide a secure network that is immune to interference. media limited. and focuses on the home and business market. It is.
It includes a set of signal rate multiples for transmitting digital signals on optical fiber (OCx). To be more precise. much like E1 is to T1.6). a call. It carries all the bits from say. Inc. It uses Synchronous Transport Modules (STM). it is the European equivalent of SONET. which is intended for use by large businesses.Switched Multimegabit Data Service offers high bandwidth at speeds of up to 34 Mbps.84 Mbps (OC-1) all the way up to 40 Gbps (OC-768). Internationally. has twentythree 64 Kbps B-channels for data or voice (1. SONET SONET (Synchronous Optical Network) is a fiber optic-based technology that specifies the speeds at which the equipment can multiplex signals from sources into high-speed carrier devices. This service is provided by some local companies and works well for MAN installations (compatible with IEEE 802. data and video at rates ranging from 51. ISDN PRI (Primary Rate Interface). Specialized Solutions. and one 64 Kbps D-channel for control.Chapter 7 – Expanding a Network B-channels for data or voice (128 Kbps).544 Mbps). The data-rate can vary anywhere from STM-1 (155 Mbps) up to STM-64 (10 Gbps). 175 . like OCx with SONET. SMDS SMDS . It is capable of transmitting voice. and one 16 Kbps D-channel for control. SDH SDH (Synchronous Digital Hierarchy) is a standard technology for synchronous data transmission on optical media. it is considered the equivalent of Synchronous Optical Network. within one transmission frame.
600 bps. As we have already learned. A modem is a device that makes it possible to communicate long distances over standard telephone lines or cable. Sometimes included with the purchase of a computer. network cards. Some of the basic functions of a modem are to: • • Convert digital signals used by computers into analog signals that can be transmitted via telephone lines.400 bps. times as fast as the Baud rate. FAX modems will send and receive data at speeds up to 14. a given Baud rate could transmit data at 2. This limit cannot be exceeded without encountering signal distortion.400 High-speed version of the V. the term Baud has disappeared and been replaced with bps. Originally modem speeds were measured in terms of Baud.32 V. With early modems. modems have reached a new technology limit of 56. The name is derived from the words MOdulate and DEModulate. due to the physical characteristics of copper wire and the effects of transmitting signals over long distances. Today. To increase our network beyond a few computers. connecting a few computers to form a local area network requires cabling and network cards. 176 Specialized Solutions. 14. Modems are classified by a "V" rating. To overcome this and increase the speeds of data transmission via modems.Network + Training & Test Preparation Guide Modems Expanding a network requires an understanding of the additional devices necessary to make the connections. Inc. The following is a list of common "V" ratings: Standard V. 4. . The problem with these devices is that they all have limitations that prevent long distance communication. the Baud rate was equal to the bps. Therefore. However. Modems are available in both internal (standard expansion card) and external (connected to a serial port and has its own power supply) versions. etc. designers learned how to place several signals within one cycle.22bis V. requires some additional hardware that will overcome the limitations of the cables. and media. The Baud rate equals the frequency in cycles per second that can be transmitted via telephone lines. or over long distances. Sometimes included with the purchase of a computer.600 bps. With this change. Speeds will range from very slow speeds of 300 bps to 56.32 standard.32bis bps 2400 9600 Notes An old standard. These speeds are measured as bits per second. there is a limit of 2400 Baud. Convert the parallel digital data into serial digital data. 8. Modems transmit data at various speeds.
600 Backwards compatible with earlier V.FastClass. 56. 177 . Specialized Solutions.34 V.800 Improved V.42 V.600 56K modem standard – resolved competition for standard between US Robotic X2 and Rockwell K56 Flex standards. modems – error correction standard.32terbo V.200 Not officially a standard yet. Inc. Will only communicate with another V.32terbo. 28. Backwards compatible with earlier V. modems.90 19. 57.Chapter 7 – Expanding a Network V.
The trick is that you cannot use just any cable with 9-pin female connectors. There are many off-the-shelf software packages that will perform this type of communication. In addition. By running Network Connections Wizard and following the simple 178 Specialized Solutions. the computer is acting as a server or gateway to a network and will receive calls via a modem from other computers. Any two computers can be connected. For example. Also. . or directly via COM ports and a cable. so this cable eliminates that part of a modem connection. On the other hand. Dial-up networking is the client-side of the connection. Inc. This is a specially wired cable that actually replaces the modem. while a true server like Windows Server 2003 will allow 256 inbound connections. You must use a Null-Modem cable. or RAS (pronounced RAZ) connection.Network + Training & Test Preparation Guide Remote Access Computing (RAS) One of the most common forms of expanding a network is through a Remote Access Server. The difference between a simple computer (Windows XP or Windows 95/98) and a RAS server (such as Windows Server 2003) is the number of inbound connections. Since the two computers are directly connected. You may be more familiar with the term dial-up network (DUN). when you access your Internet connection from your computer at home (via a modem connection) you are establishing a dial-up connection –you are the client. A system running Windows XP or Windows 95/98 will allow only one inbound connection. Both computers will have to run compatible software so that one will act as a server and the other as a client. there will be no need to connect to telephone wires or dial a number. RAS Connection Connecting Two Computers Establishing a remote connection can be either between two computers or between a remote computer and a network. both of these terms mean the same thing. Let's first look at connecting two computers. With RAS. the COM port provides the parallel to serial data conversion that is necessary to complete a connection. When connecting two computers in close proximity (same room or building). Actually. the server that you call (your Internet Service Provider) is providing a RAS connection to you – it is the server that is providing the connection to the Internet for you. The difference is how each computer is being utilized. Windows XP has an feature called a direct cable connection. all you need to do is connect a cable between a COM port on each computer. A COM port is a 9pin male connector (it can be 25-pin but this is not as common as the 9-pin) on the back of the computer. either via modems and telephone lines.
While this was the protocol of choice for a Specialized Solutions. you can set up the proper configuration for the connection and dial the appropriate number. but is still in use with some systems. RAS/DUN supports various connection protocols to ensure proper connections and security. you will use a modem to establish the connection. the server will answer the phone and allow the connection if you are an authorized user. From this accessory. Inc. RAS Protocols In order for any connection to work. you can connect any two Windows-based computers and share data with only a cable connection. On the server side. Windows (95/98 and NT) has an accessory called Dial-Up Networking. both computers must be using the same protocol. in this case. the RAS software must be installed and running. Direct Cable Connection Making a RAS connection to a server is similar to a direct connection but. On the client side. 179 .Chapter 7 – Expanding a Network instructions provided. These protocols are: • • • • • • • • • SLIP (Single Line Interface Protocol) PPP (Point-to-Point Protocol) PPTP (Point-to-Point Tunneling Protocol) IPsec (Internet Protocol Security) L2TP (Layer Two Tunneling Protocol) SSL (Secure Socket Layer) TLS (Transport Layer Security) Kerberos (Greek mythology – three-headed canine who guards Hades' gates) ICA (Independent Computing Architecture) SLIP (Single Line Interface Protocol) Serial Line Interface Protocol is a standard protocol for connections using TCP/IP (Transmission Control Protocol/Internet Protocol). Normally. With this in place. your computer will have to make the phone call and provide the necessary security authentication information to the server. the client computer will establish the connection via DUN software. The server you are contacting may be an individual computer or a server that provides access to a larger network. This is a relatively old standard (1984).
It cannot encrypt logon information. It provides security. Some of these disadvantages include: • • • • • It requires a static IP address for each node. It provides data compression and error control. Inc. .Network + Training & Test Preparation Guide long time. RAS and Security. such that only the sender and the receiver can accurately interpret the data that is being sent. and DECnet. IPX. Some of these improvements include: • • • • Support for TCP/IP. It is designed to protect IP packets as well as to provide defense against network attacks. It supports encrypted passwords. Many organizations are using tunnels. NetBEUI. PPP was intended to overcome these limitations and is very common today. It transmits in text only. It's only supported by RAS clients. It supports only TCP/IP. created by PPTP and other tunneling protocols. PPTP (Point-to-Point Tunneling Protocol) Point-to-Point Tunneling Protocol (PPTP) provides for a secure encrypted tunnel for communication through the Internet. It enables highly private network links over the public Internet. in today's networks it has several disadvantages. Encrypted Connections. the limits of SLIP caused many problems. as a less explensive alternative to costly leased lines. • • • • • IPsec IPsec (Internet Protocol Security) is a framework of open standards for security at the Network layer of the OSI model. VPN (Virtual Private Networks). With the rapid growth of the Internet and remote communications. It can be used in conjunction with VPNs (Virtual Private 180 Specialized Solutions. This is accomplished by encapsulating one protocol with another protocol. AppleTalk. Secure transmission over TCP/IP networks. PPP (Point-to-Point Protocol) The Point-to-Point Protocol was designed as an upgraded protocol to SLIP.
both sending and receiving. are the ones aware of the IPsec transmission. Inc. ESP. certificates (like X. It does not provide authorization. ICA (Independent Computing Architecture) ICA is a remote connection established using Citrix software (like WinFrame or MetaFrame) and a thin client environment. L2TP Layer Two Tunneling Protocol (L2TP) is the latest version of the tunneling protocol. It uses a key to encrypt the data. Specialized Solutions. discussed here in the next chapter. it only establishes the user's identity. or virtual proof-of-identity cards so the user can request a service from a server.. authenticates the sender of data and encrypts the data as well. as does Novell Directory Services (NDS). meaning that the computers.Chapter 7 – Expanding a Network Networks) and remote access for users who need access to resources on a private network. Kerberos V5. most relating to higher security. IPsec allows for either ESP (Encapsulating Security Payload) or AH (Authentication Header). . It is based on an end-to-end security model. It functions at the Data-link layer of the OSI model and is used in conjunction with VPNs.509) and preshared keys can be used for authentication in conjunction with IPsec. limited RAM. Linux. UNIX. it does not require IP connectivity. Kerberos Kerberos is a secure method for authenticating a request for a service in a computer network. and a processor in the range of 200 MHz to 300 MHz. and Macintosh computers. Unlike PPTP. TLS TLS (Transport Layer Security) is the evolution of SSL. Windows 2000 and Windows Server 2003 Active Directory use this type of security by default. Thin clients are computers with no hard drive. ICA can be used with Windows. It allows a user to request an encrypted ticket. usually a user's credit card number. L2TP offers many advantages over PPTP. It is transparent to the user. It combines Cisco's Layer 2 Forwarding (L2F) with PPTP. AH only authenticates the user. which is the highest security method. 181 . SSL The Secure Sockets Layer (SSL) is a protocol for addressing the security of an Internet transmission between a client and a server. It can work with SSL and uses Triple DES encryption (three 56-bit keys). a bare-bones operating system (such as Windows CE). It is included in both Microsoft's Internet Explorer and Netscape's Navigator and it is a complimentary addition to HTTPS.
you can restrict the numbers that RAS will call. and any other software that might use the modem. The type of communication port you intend to configure. Callback Security One method of providing both security and cost control is to require the server to callback anyone that attempts to logon. . This feature can also be used to ensure long distance charges are charged to the company rather than the caller. you will have to collect all the information from your operating system supplier to ensure that you have everything necessary. your new RAS system may not be able to gain access. you will need to collect data on the type of connection you intend to make and the specifics of the computer hardware and network.Network + Training & Test Preparation Guide In addition to providing remote sharing of information. Be sure to check everything including the RAS configuration. you must implement or enable them during configuration of the RAS server. Security Host (Bastion Host) A security host or bastion host is a separate server that works between the RAS server and the client. and thus more security. RAS provides several layers of security. If another software package has "control" of the modem. installing RAS can be frustrating. Installing and Configuring RAS Installing RAS on a server is dependent on the network operating system installed on the server. you will have to carefully go through all the configuration parameters and check every one. the modem configuration. In addition. As with all security measures. If it does not work the first time. Before installation. This provides for additional authentication. 182 Specialized Solutions. This audit can include who signed on and when they signed on. At a minimum you will need to know the following: • • • Your modem specifications including having the appropriate drivers for your network and/or computer operating system. Are there any client protocols that will have to be enabled? • What are the security requirements of the connection/network? Troubleshooting a RAS setup While not usually complicated. Here is a summary of RAS security functions: Auditing The server can create and maintain an audit trail of all connections. Inc. This is a great benefit for those who travel for business and need access to the network. therefore ensuring that the connection is legitimate. By requiring RAS to call back to the client that is requesting a connection. All it takes is one number or check mark out of place to prevent the connection from working properly.
you will need to understand both its strengths and weaknesses. Inc. As a networking professional. The latest Microsoft server operating systems such as Windows 2000 Server and Windows Server 2003 have wizards that make installing an RAS server much simpler. Specialized Solutions. it is not always the solution for every network. and you don't need a fulltime connection. 183 . You should consider RAS when your bandwidth is less than 128 Kbps. you want to keep the costs down.Chapter 7 – Expanding a Network Limitations of RAS As good as RAS is.
Hint: There's a glossary in the back of this book. Keyword Analog Signal Bridge Carrier Concentrator CSU/DSU Digital Signal DUN Frame Relay Gateway Hubs ICA Ipsec ISDN Kerberos L2TP MAU PPP PPTP RAS Repeater Router SDH 184 Specialized Solutions.Network + Training & Test Preparation Guide KEYWORDS Exercise Define each of the following keywords. Definition . Inc.
Inc.25 Definition Specialized Solutions.Chapter 7 – Expanding a Network Keyword SLIP SMAU SONET SSL T1 VLAN X. 185 .
9. Inc. 7. Name three advanced WAN environments. What is the difference between a hub and a MAU? 2. Name three RAS protocols. What are the two components of remote network accessing? 8.Network + Training & Test Preparation Guide Review Questions Chapter 7 1. and a gateway.544 Mbps transmissions is called? 6. a router. . What is analog communication? 5. Name four forms of RAS security. Describe the difference between BAUD and bps. What is the difference between an active hub and a passive hub? 3. 10. Define a repeater. a bridge. A form of digital line that is capable of 1. 186 Specialized Solutions. 4.
187 .Chapter 7 – Expanding a Network Specialized Solutions. Inc.
as well as Internet standards. The four layers are: Application. TCP is built on top of IP (Internet Protocol). and the Internet. Transmission Control Protocol (TCP) is the most common Transport layer protocol (based on the OSI Model). Specialized Solutions. These standards. Although RFCs are not true standards (they are documents that describe work in progress). 189 . Transport. such as SMTP. Inc. Full duplex means that data can travel in both directions at once. Internet and Network Interface. which will be discussed later in the chapter. these protocols were available on UNIX early on. This is the most common protocol suite with which a networking professional works. it has evolved into the protocol of the Internet. TCP/IP. are the responsibility of the IAB (Internet Activities Board). TCP/IP was developed by the Department of Defense agency (DARPA) in the 1960s as part of a military research project. some are considered to be Internet standards. TCP/IP was designed to accommodate a large internetworking environment comprising several different types of computers. SNMP. The TCP/IP suite consists of four layers. known as BSD UNIX. Each layer maps to one or more layers of the OSI model. the recognized standard for internetworking altogether. intranets. and is usually seen in the combination. TCP/IP is an open protocol and is considered to be an industry standard. Its popularity is largely attributed to the fact that it is not owned by a specific vendor. TCP/IP is now the standard on all versions of UNIX. and is in fact. Also. RFC (Request For Comments) A series of documents called RFCs (Request For Comments) serve as the standards that were used in the development of TCP/IP. It is also used with Ethernet networks. From this beginning.Chapter 8 – TCP/IP Essentials Chapter 8 – TCP/IP Essentials Introduction to TCP/IP TCP/IP is an internet (between network) protocol. and FTP. It is important for the networking professional to know that TCP/IP is used on the Internet and that it can be used with almost any network operating system. and were even built into the Berkeley Standard Distribution. TCP/IP is a routable protocol that provides full duplex connections. The TCP/IP protocol suite includes a number of protocols.
Network + Training & Test Preparation Guide TCP/IP and OSI The four layers that make up TCP/IP provide a guideline for this model.Transmission Control Protocol UDP – User Datagram Protocol IP – Internet Protocol ICMP – Internet Control Message Protocol ARP – Address Resolution Protocol 190 Specialized Solutions. These five protocols are: • • • • • TCP. . Inc. There are actually five protocols that work within these layers to provide network connections.
191 .Chapter 8 – TCP/IP Essentials Specialized Solutions. Inc.
It then routes the information to its destination. TCP operates by first establishing a connection-oriented session through the use of ports and sockets. Inc. The Top Five TCP/IP Protocols As mentioned earlier. they can be retransmitted in a timely manner.Network + Training & Test Preparation Guide TCP/IP Protocols As a network technician. Let's take a look at how this works. The following list provides a few examples: For: FTP TELNET SMTP HTTP POP3 Use Port 21 23 25 80 110 192 Specialized Solutions. the origination point and destination point of the computers between which data travels are called ports. It will then use the concept of sliding windows and acknowledgements to ensure fast and accurate data transmission. On a TCP/IP network. called packets. or into even smaller units of measurement called datagrams. However. Its job is to ensure that data transferred from one computer to another reaches its destination intact. there are five major protocols used within TCP/IP. and for the Network+ exam. you will need to know the various protocols and how they relate to the OSI model. TCP Transmission Control Protocol (TCP) functions at the Transport Layer of the OSI Model. Should lost or corrupted packets be detected. you will not have to be an expert on the workings of TCP/IP. Port numbers are generally predetermined and correspond to a specific service that is running on a machine. A port is a virtual outlet that can be opened on a network device. TCP breaks data into tiny chunks. Let's take a look at them. Port numbers for some protocols are better known than others. and reassembles the data. This data exchange can be verified at various checkpoints. .
The registered ports are associated with the range from 1024 through 49151.535. IP Internet Protocol (IP) is the Network layer part of TCP/IP. an acknowledgement of receipt is returned. The advantage of UDP over TCP is speed and is often used when transmitting streaming audio or video. 193 . nor does it check for errors. The IP header consists of the source and destination addresses. The private or dynamic ports are associated with the range from 49152 through 65535. The addresses. UDP transports data. The well-known ports are associated with the range of possible port numbers from 0 through 1023. Although the terms. consist of a unique 16-bit numeric address ranging from 0 to 65. which is responsible for moving the data from its origination point to its destination point. or port numbers. Sliding windows are used to increase the speed of data transfer. inserting its own header into the datagram when it is received from TCP. If the transmission has not been successful. TCP tells IP that the data has arrived at its destination. Think of it as a return receipt like the one you get from the Post Office when you want to be sure that a package has been delivered. UDP packets are delivered through ports and sockets and do not require the opening of a session. The port number identifies the application associated with the data. IP merely routes the data. Transmission speed is increased by sending a window of information at a time without having to get an acknowledgment back for each packet. Both machines keep track of the data so that any packets not received can be resent. This communication is called a session and is used to provide guaranteed delivery between the two machines. Telnet. i. etc. UDP User Datagram Protocol (UDP) is a connectionless protocol residing on the Transport layer of the OSI Model. meaning that it establishes an end-to-end connection and starts transmitting without swapping control information. you are automatically connected to the correct port for that particular data type. Inc. and a Specialized Solutions.Chapter 8 – TCP/IP Essentials The sending computer's address is called the source port number. and specify a certain protocol. When you open a dial-up connection to the Internet. This allows a receiving machine to collect packets out of order and hold them in a buffer until all packets in a specified group are received. FTP. IP is connectionless.. Connection-Oriented Communication means that direct communication is established between two machines.e. TCP will retransmit the data. HTTP. For each packet sent. a port is different from a socket. A socket is the combination of an IP address and a port number. Both machines have a sending and receiving window to buffer the data flow. but does not acknowledge delivery. Acknowledgements are used to ensure the reliability of the data being transmitted. "port" and "socket" are often used interchangeably. the protocol number. and the receiving computer's address is called the destination port number.
Network + Training & Test Preparation Guide checksum. The IP header is necessary so that gateways are able to determine where to route the datagram. Note: A checksum is simply a calculation that is performed on data by the sending computer. To be more specific, the checksum is the answer that is derived from this calculation. When the data arrives at the destination computer, the receiving computer performs the calculation. If the checksum is the same, the data is assumed to have arrived intact. The following are key elements of IP: Addressing – provides the address of both the sending and receiving machines. Broadcast – provides broadcast addressing within a network segment. Fragmenting and Reassembly – if data packets are too large for the underlying network, it will be broken down into a manageable packet size for transport. Routeability – provides routing information from one network to another. Time to Live – provides TTL data. This defines the number of hops a packet can make before it is discarded. ICMP Internet Control Message Protocol is part of the Internet layer. It is responsible for errors and messages regarding delivery of IP datagrams. ARP The Address Resolution Protocol is responsible for keeping track of the mapping of IP addresses to physical addresses. Each device on the network maintains an ARP cache. This cache contains a list of all the devices with which it is communicating. The contents of a cache can be displayed by using the ARP.exe command in Windows or the /sbin/arp command under UNIX. Other TCP/IP Protocols In addition to the top five, TCP/IP uses several other protocols: POP3 Post Office Protocol Version 3 (POP3) allows the client computer to retrieve E-mail from a POP3 server using a temporary connection. IMAP4 Internet Message Access Protocol (IMAP) is also a protocol for accessing email from your local server. Your Internet server holds your incoming email until users logon and download it. It is more advanced than POP3 because you can use folders and mailboxes on the server, run searches, or access multiple mail servers. 194 Specialized Solutions, Inc.
Chapter 8 – TCP/IP Essentials POP and IMAP allow a client to pull their mail from a server. Simple Mail Transfer Protocol (SMTP), a protocol for transferring e-mail between points on the Internet, which is what you use when you send out mail. SMTP is server to server, whereas POP or IMAP are client to server. SMTP Simple Mail Transfer Protocol (SMTP) is a server-to-server protocol that acts under the control of the message transport system. SMTP is used to transfer E-mail between computers, usually over the Internet. An easy way to think of it is SMTP stands for "Send Mail To People." SNMP Simple Network Management Protocol (SNMP) is the Internet protocol that manages nodes (individual computers) on an IP network. SNMP is not limited to TCP/IP. FTP File Transfer Protocol (FTP) is a client-server protocol that allows a user to transfer files from one computer to another over a TCP/IP network. The user accesses a special directory hierarchy containing public access files, by typing in a user name, or the word "anonymous." The password is the user's E-mail address. Files may then be uploaded or downloaded between the computers. HTTP HyperText Transfer Protocol (HTTP) is a client-server protocol that is used on the World Wide Web (www) to access HTML documents, such as web pages. HTTPS HTTPS (Secure Hypertext Transfer Protocol) is a Web protocol that encrypts and decrypts, using SSL as a sub layer underneath HTTP, allowing access to a secure Web server. It uses port 443, the secure SSL port instead of port 80, the HTTP port. HTTPS, as well as SSL, allow for the use of X.509 digital certificates for authentication of a user.
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Chapter 8 – TCP/IP Essentials
Naming Systems
Naming conventions and addressing is a large part of networking and TCP/IP. Remember, we are working in two worlds, the computer world of numbers and our world of user-friendly names. Understanding the difference between these two worlds and how to work in both of them is an important part of networking. DNS Domain Name Service (DNS) is a network service that translates hostnames to IP addresses over a TCP/IP network. The network administrator defines and configures the DNS settings using a standardized lookup table. DNS functions like a telephone directory. The network administrator need only remember the host and domain names. A domain name server is a computer that "remembers" the user-friendly names of the other computers and their IP address numbers. For example, the domain bigcompany.com may have an IP address of 188.8.131.52. This allows users to simply remember the userfriendly name while the domain name server remembers the numbers used by the network computers. A domain is a group of computers that share a common general purpose, such as government, education, commerce, or interest. Internet domains are established in a hierarchical order. A Fully Qualified Domain Name (FQDN) consists of a hostname and a domain name. The Internet Network Information Center (InterNIC, also known as Network Solutions) controls the top-level domains. These domains require suffixes such as .com for businesses or .edu for educational institutions. It is also common practice for various companies to register domain names for you.
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Network + Training & Test Preparation Guide The following table lists some Internet domains:
.com .net .edu .org .gov .mil .biz .pro .info .xx
Commercial Organizations Networks (The backbone of the Internet.) Educational Institutions Non-profit Organizations Non-military Government Organizations Military Government Organizations Businesses Professional Information services Two Letter Country Code For instance, Big Company Inc. in Italy might be http://www.Bigcompany.com.it or in Australia www.Bigcompany.com.au. Also, .tv is gaining in popularity. Tuvalu is a small country, which receives financial benefit from the registration fees.
WINS In a Windows-based network, the Windows Internet Name Service (WINS) is used to resolve NetBIOS computer names to their IP addresses. This is a dynamic service and requires that the workstation register with the WINS server each time it logs on to the network. NETBIOS NetBIOS defines a session-level interface and a session management/data transport protocol so computers can converse in session mode or send messages without connection in datagram mode, leaving the responsibility for error-checking up to the application. A NetBIOS name is a unique 16-byte address (only 15 can be used for the actual name) used to identify a NetBIOS resource on a network. There are four node types: B-node (broadcast), P-node (peer-peer), M-node (mixed – B and P) and H-node (hybrid – P and B). 198 Specialized Solutions, Inc.
Chapter 8 – TCP/IP Essentials HOSTS file HOSTS file is a static text file that maps host names to IP. It predates DNS. It must be manually created and changed. LMHOSTS file LMHOSTS is static text file that are used to look up and resolve NetBIOS names and IP addresses. It predates WINS and is rarely used today. It must be manually created and changed. IP Gateway A gateway is used to connect two networks with dissimilar protocols. For example, it could connect a LAN to the Internet. In order for a gateway to work with the Internet, it must be assigned a static IP address. This means that it is permanently assigned. It would be difficult to find if it were constantly changing. DHCP Assigning IP addresses is like assigning telephone numbers, sooner or later we will run out of numbers. In smaller isolated networks, IP address assignment is not a big problem and each workstation or device can have a static address. However, as the number of addresses required increases, you will sooner or later come up with a number shortage. To resolve this, IP addresses can be dynamically assigned. That is, assigned on an "as needed" basis. Each host will lease an address only for the period of time required. When not needed, the address can be leased to another host. To accomplish this, you will need to use Dynamic Host Control Protocol (DHCP). Upon logon a DHCP server will provide a client with an IP address, subnet mask, and a default gateway if needed. Notice that the IP addresses are leased. This means that they will expire after a specific amount of time. This is to prevent one user from monopolizing the connection. A lease can be renewed. When the term of the lease is at 50%, the client will send a request for renewal. If the demand for connections is low (there are spaces available), the lease will be renewed without interruption. If not renewed, the client will attempt to contact the DHCP server that issued it the IP address directly about every 5 minutes until it reaches 87.5% of the lease, at which time the client will broadcast a request to obtain an address from any available DHCP server. If all addresses are being used or a DHCP server does not respond, the lease will expire and the address will be assigned to another user. In this case, the original user will have to wait for an opening before getting another lease and a new IP address. BOOTP BOOTP (Bootstrap Protocol) is a protocol that is used by diskless workstations to obtain their IP addresses (as well as the server's address and its default gateway) from a BOOTP server. BOOTP was the foundation of the Dynamic Host Configuration Protocol (DHCP).
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we talked about the client/server relationship in terms of the roles of various users and servers. Proxy Server ICS ICS allows computers within a network. Compare this to a "he said-she said" scenario where an intermediary delivers the message between two parties who do not speak directly to each other. like a LAN.Network + Training & Test Preparation Guide Network Connection Utilities NAT NAT (Network Address Translation) is the translation of an IP address used within an organization internally (private IP address) to an IP seen by the Internet (public IP address). . The user is connecting to the Internet via a secondary source. In the case of a proxy server. it serves many clients through only one connection. Actually. i. The proxy server is actually making a connection to another network or to the Internet on behalf of the client. since it keeps the private IP addresses hidden from the outside world. The proxy server is a liaison between the two parties. It can also work in conjunction with Routing and Remote access. 200 Specialized Solutions. Inc. The proxy server may function in the role of the server or the client. the proxy server. to share a single connection to the Internet. but it is most often used between a private network and the networks public address or addresses. It contains DHCP. ICS allows multiple users to fully utilize that connection by performing different tasks at the same time. depending on the direction in which the communication is traveling at any given time. IP Proxy Servers Earlier. It allows for use of one public IP address for many private IP addresses. NAT. a NAT is just a device or program that translates one set of IP addresses to another set of IP addresses. NAT also acts as a type of firewall. who think they are communicating directly with one another.e. and DNS.
Chapter 8 – TCP/IP Essentials Specialized Solutions. 201 . Inc.
are assigned by the Internet Corporation for Assigned Names and Numbers (ICANN) and these IP addresses are further divided into classes. Internet IP addresses.194. 2nd octet: The value of the 2nd octet is 39.8. It is important that the networking professional have a basic understanding of these classes. 3rd octet: The value of the 3rd octet in our example is 8.00001000. The result is called a dotted decimal number.11000010 Each octet represents a number between 0-256: 1st octet: 0 0 1 0 0 0 0 1 ----------------------------------------------------------------16 8 2 1 128 64 32 4 1 0 0 1 1 1 0 0 ----------------------------------------------------------------128 64 32 16 8 4 2 1 0 0 0 0 1 0 0 0 ----------------------------------------------------------------32 16 8 4 2 1 128 64 1 1 0 0 0 0 1 0 -----------------------------------------------------------------128 64 32 16 8 4 2 1 Adding the values assigned to the "1" positions gives us a value of 33 for the first octet. Each of these octets represents a number from 0-256. A 32-bit binary number can represent (232) or 4.2 billion) different numbers. If a network is internal and does not access the Internet. This IP address is a 32-bit binary number.967. . So the dotted decimal address of our example is 33.00100111. the administrator may assign an IP address to each computer (as long as the number is unique). Imagine how difficult it would be to have to remember a combination of 32 1s and 0s for each address. let's now take a look at IP address numbers. Although that is easy for a computer. they are broken down into four octets.296 (4.294.Network + Training & Test Preparation Guide TCP/IP Addressing IPv4 Enough talk about IP address names. 4th octet: And finally the value of our 4th octet is 194.39. Inc. An octet is a group of eight binary digits and a period or "dot" separates these octets. A basic knowledge of the binary numbering system is required to understand network addressing: The 32-bit binary number: 00100001001001110000100011000010 Broken down into four octets: 00100001. To simplify these addresses. however. 202 Specialized Solutions. Network computers require a unique IP address so that the other computers on the network can identify them and be able to communicate with them. it is not easy for us.
39.194 where the Network ID would be 193. The leading bit in the binary representation of a Class B address is always 1 (10000000). The first octet (33) would identify the network (Network ID) and the rest of the octets would identify the host (Host ID) 39. Class A Class B Class C Class A Addresses If the network applying for Internet IP addresses is extremely large. 203 . The first octet of a Class C address is always a number between 192-223.39. The first two octets identify the network (Network ID) and the last two octets identify the host (Host ID).8. you should pay special attention the Classes A. For the Network+ exam. The example we used to define a dotted decimal address of 33. There are five common classes: A through E.Chapter 8 – TCP/IP Essentials IP Addresses The dotted decimal number is further broken down into two components. only the first octet is used for the Network ID and all three remaining octets identify the host (Host ID).194.39. Class C Addresses These are the most common and are used for smaller networks.39. the network is divided into classes.8.) The first octet in a Class A address is always a number between 1 and 126.8. The class can be determined by the value of the first octet.39 would be the Network ID and 8. The leading bits in the binary representation of a Class C address are always 11 (11000000).194 would be the Host ID. Inc.8. (A host may be any device on the network. An example of a Class B IP address would be 129. the first octet on the left is always part of the Network ID and the last octet on the right is always part of the Host ID. 01-126 128-191 192-223 (leading bit = 0) (leading bit = 1) (leading bits =11) Specialized Solutions. An example of a Class C IP address would be 193. Depending on the assignment. Class B Addresses This class is assigned to medium sized networks. The octet(s) on the left represents the Network ID (Network ID) and the octet(s) on the right represents the Host ID (Host ID). In this class the first three octets are used for the Network ID and only the last octet is used for the Host ID. Within classes. The first octet in a Class B address is always a number between 128 and 191.194 would be an example of a Class A address.194. In this case 129. Class D and Class E Addresses Class D cannot be used for networks (multicast) and Class E IP addresses are reserved for future use. The class of the IP address determines which octets identify the Network ID and which octets identify the Host ID. B and C. The leading bit in the binary representation of a Class A address is always 0 (00000000).8 and the Host ID would be 194. The two octets in the center can be either assigned to the Network ID or the Host ID.
(For example. All in use and no longer available. Class C . there are some IP addresses that are reserved for special purposes: Addresses that begin with 127 and 224 through 255 are used for testing purposes and for multicasting and are not available for normal host addresses. if a network is going to be connected to the Internet. you must petition the official Internet authorities for the assignment of a network address. B or C address. This is the loopback address. Class C IP addresses are still available. and they are responsible for the assignment and regulation of IP addresses.used by very large networks. there are only 65. Class C has a large number of Network IDs and only a few Host IDs.used for smaller networks that do not exceed 254 hosts. so there are only 254 addresses available for hosts. the Network ID of 127 designates the local node and allows that node to send a test packet to itself without generating network traffic.223 In addition. Inc.1) Class A .534 possible Host ID numbers. there are 16.0. You can see that Class A has the largest number of hosts. . Use the following table to memorize the different classes: CLASS A CLASS B CLASS C 1 . Class C uses three octets for the Network ID and only one for the Host ID. This organization is called InterNIC (Internet Network Information Center).0.214 possible Host ID numbers.777. Class B uses two octets for the Network ID and two octets for the Host ID. Note: The existing shortage of addresses has made it impossible to obtain a Class A address for a long time. As we mentioned earlier. Class B . specifically 127.used for medium-sized networks. Likewise.Network + Training & Test Preparation Guide Since a Class A Network ID uses the remaining three octets to assign numbers for the Host ID. with the least number of Network IDs.191 192 .126 128 . Also. 204 Specialized Solutions. Class B IP addresses are all in use and no longer available. Some IP Addresses are reserved for special purposes: If: All Zeros All Ones 127 Network ID This Network All Networks Local Node Host ID This Node All Nodes IP Address Default Route for RIP Broadcast It is important for the networking professional to be able to identify whether an IP address is a Class A.
Chapter 8 – TCP/IP Essentials Contact InterNIC at: Network Solutions InterNIC Registration Services 505 Huntmar Park Drive Herndon. IPv6 (IP Next Generation) IPv6 (IP Next Generation) is the latest IP technology. to define the address type. demand high bandwidth. Inc. The address types are Unicast. as compared to IPv4. Unicast is an address for a single host. For example. Anycast. The benefits of IPv6 include improved scalability. however. A double colon can be used to represent multiple contiguous fields of zeros. VA 22070 You can also E-mail to hostmaster@internic. It uses eight 16-bit pieces with colons as separators as opposed to the full stops used in IPv4. It uses 128-bit addressing. but at least one must be left in each 16-bit field. 205 . as well as ease of configuration and security built right in. the following address 0000:0000:0000:0000:0000:0000:0000:0000 0000:0000:0000:0000:0000:0000:0000:0005 can be represented in their compacted form by :: ::5 You cannot. This happens to supercede the rule about one zero having to be left in a field. and Multicast. IPv6 uses format prefixes (FP). which only uses 32-bit addressing. however.net. Rather than having "classes" like IPv4. You can compact multiple fields of zero beyond the previous example. which are variable-length fields that comprise the high-order bits. An example of IPv6 is as follows: AAAA:BBBB:0000:0000:0000:0081:FFFF:DDDD A shorthand version of the previous IPv6 address: AAAA:BBBB:0:0:0:81:FFFF:DDDD Leading zeros can be taken out. It does. Here is an example of a Unicast address: 1070:0:0:0:7:777:300F:754B Specialized Solutions. It would make it unclear as to what was represented. IPv6 uses hexadecimal numbers (0 to 9. use the double colon more than once in an IPv6 address. then A to F) instead of decimal because of the length of the new addressing scheme.
An aggregatable global address uses a fixed prefix of 2000::/3. Multicast. Finally. Link-local address and IPv4-compatible address. All in all. A Site-local address uses the prefix FEC0::/10 and can be regarded as private addresses. . is an address for a group of hosts within a scope and has a FF00::/8 prefix. just like 127. Link-Local addresses use the FE80::/10 prefix and are used by hosts on a local link. IPv6 allows for a multitude of IP address possibilities for the future of networking.Network + Training & Test Preparation Guide Unicast addresses can be broken down further into four sub-groups: Global aggregatable address. Inc. The Loopback address in IPv6 is 0:0:0:0:0:0:0:1 or ::1. since they can be used to limit traffic to a domain.0. IPv4-compatible IPv6 addresses have zeros in the section beyond the normal IPv4 32-bit address (0:0:0:0:0:0:A:B:C:D or ::A:B:C:D) Anycast is an address for a set of interfaces that typically belong to different hosts and is delivered to the closest one. 206 Specialized Solutions.0.1 with IPv4. Site-local address. which replaces broadcast.
0.0.00000000 or 255. you can reduce the overall network traffic.0. 255.Chapter 8 – TCP/IP Essentials Subnetting Subnetting is the process of creating more than one private network from one public network address by customizing your subnet mask. or 225. Inc. have all 1s to the left and all 0s to the right. For example: 11111111.00000000.0 (Class A). the results will be the actual network portion of that IP address (not necessarily the default network portion determined by its class). By using subnets. lets look at subnet masks. This is done with binary addition (anding). Specialized Solutions.255.0. A subnet mask is an IP address (dotted-decimal number) in which all ones represent the network portion of the IP address and all zeros represent the host portion of the IP address. Subnet masks with full octets (255) are the default subnet mask. separating it from the host portion of the address.255.0. a large university may have a network spread over several buildings and perhaps remote campuses. For example. a router can determine which addresses are local and which addresses are for other subnets within the network. In this example.777.0 Class A (16. By using a concept called anding. all the traffic within a building or campus will be kept locally except when it needs to go to another subnet.0 255.255. The purpose of a subnet mask is to determine the network portion of the IP address.216 hosts) Class B (65.0 In regard to classful addressing .11111111.0 255. only the traffic that is not local will pass through. Anding is the binary addition that the router uses to make this determination.255. You must however.0. Before looking at anding.255. Default Subnet Masks 255.255. You can use a subnet mask that does not completely use all the bits in an octet. The number of 0s determines the maximum number of available hosts within the sub-network.0. 207 .0 (Class C). If you "and" the IP address to the subnet mask.534 hosts) Class C (254 hosts) Note: You cannot use IP addresses with all 1s or all 0s. a subnet mask can be 255.255. Since a router connects each subnet.0 (Class B). which uses a certain logic to determine the network portion of the address.
00000000 (33. a router can determine if a message is for a destination on the local network or for a machine on a remote segment.32 and the Host ID is 7.0.8.00001000.0) equals 00100001. while the Host ID 0.32. By using this method.0) Noticing that all the places that have ones. and through leaving only the digits for the network portion or 33. The following tables summarize IP addresses and subnet masks: 208 Specialized Solutions.00100111.194.00000000 (255.11100000. thus reducing the traffic on the rest of the network. it recognizes the first 11 bits as the network portion of this address. using our previous example of 33. Any local addresses will not pass through. let's and it to the subnet mask of 255.0.32.8.00000000. Those 11 bits equal a network portion of 33. The network and host portions do not break down neatly into octets since the subnet mask does not take up a complete second octet.194.00000000.7.0. .0.0.39.00100000.32. The remaining 21 bits in the IP address is the host portion This equals 7.194 is determined by the zeros in the subnet mask.224.8.Network + Training & Test Preparation Guide Remember. Since the subnet mask only goes 3 bits into the second octet.224.11000010 (33. Therefore in our example the Network ID is 33.8. It is common in TCP/IP to omit the trailing octets in the Network ID and the leading octets in the Host ID.8.39. Inc. 00100001.194) 11111111.0.194. for binary addition: 1+1=1 1+0=0 0+0=0 Now.
255.b.0 255.b. Inc.0. Allows an unlimited number of hosts to communicate.a.216 65.b.0 255.c to 126. A unique host ID is required for each TCP/IP computer network interface card.b.a.c to 223.c 128. Connect a mix of network technologies (Ethernet and Token Ring).c to 191.c Default Subnet Mask 255.255.097.a. it will require an address for each subnet.534 254 How to Subdivide a Network The process of subdividing a network into logical units is called subnetting or subnetworking. If a router is connected to two subnets.0. There are several reasons to divide a network in this manner.0.777. Determine the number of Host IDs per subnet.b.a.0 Number of Networks 126 16.a.255.384 2.Chapter 8 – TCP/IP Essentials Default Subnet Mask and Network Classes Class A B C IP Address 001.0. 209 .0. • • • • Connect physically remote local networks.255.0 255.c 192.0 255.255. Reduce network traffic by limiting broadcast and local traffic to a single segment.152 Number of Hosts 16.0.a. Be sure to include some room for growth of the network.0 Maximum Networks and Hosts per Class Class A B C Default Subnet Mask 255.b. Specialized Solutions. There are steps to follow when subnetting: Determine the number of Network IDs required. A unique network ID is required for each subnet and each wide area network.255. each TCP/IP printer network interface and each router interface on each subnet.
With this number.255.240 255.255.0 255.255. we have one network with approximately 65.255.224 255.255.240.192.0 255. Class B Subnet Mask (2 to 14 bits borrowed) 255. We will use an InterNIC ID of 191.255.0 255. You should remember the formula 2n-2 where n is the number of bits borrowed.248 255.255.0 255.0 255.255.255. First.252. Inc. To begin this process.252 Bits 2 3 4 5 6 7 8 9 10 11 12 13 14 Subnets 0 6 14 30 62 126 254 510 1022 2046 4096 8190 16.255. we will notice that this is a Class B network and therefore the default subnet mask will be 255.255.254.128 255.255.255. We use this formula to determine the number of subnets that will be created by borrowing bits from the hosts.255.255. As we begin to subnet.255.255.0 255.0.192 255.36. we are increasing the number of network addresses that we can use and decreasing the number of host.255.224. The following table shows the subnet mask created by borrowing bits and how it will affect our network. you will need to start with the network ID supplied by InterNIC. We do this by using bits from the next octet or octets as part of our network addresses that we assign.382 Hosts N/A 8190 4096 2046 1022 510 254 126 62 30 14 6 2 210 Specialized Solutions.255. .255.Network + Training & Test Preparation Guide Define the Subnet Mask The goal is to define one subnet mask for the entire internetwork that gives the desired number of subnets and allows enough hosts per subnet.248.000 hosts.0 255.255.0.
Make sure that the decimal mode (Dec) is selected.36 as assigned to us by InterNIC.255.192 255.255.248 255. Make sure that it is in scientific view (that's the big calculator). Just to be on the safe side.Chapter 8 – TCP/IP Essentials Class C Subnet Mask (2 to 6 bits borrowed) 255.255.255. let's add 4 more for future expansions.240 255. We already know that the first two octets will be 10111111 00100100 from this ID. the question is how many bits of the third octet do we need to use? After examining our network requirements.252 Bits 2 3 4 5 6 Subnets 0 6 14 30 62 Hosts N/A 30 14 6 2 To make this easy. Now we get out our Windows calculator.224 255. giving us a total requirement of 18. Enter the value of 18. you can use the scientific calculator supplied with any Windows operating system. Specialized Solutions. 1. 211 . For this example.255. Change the mode to binary (Bin).255. The number 18 will now be in binary (10010). Inc. 3.255. we determine that we will need 14 subnets to meet our current needs.255.255.255. 2. lets keep our network ID of 191.
we would have had to reconfigure the entire network. This will be the number of bits required for the third octet. Inc. our answer would have been to use 4 bits and we would have been limited to a maximum of 14 subnets. The following table shows the six subnets created when using the three bits of the third octet: 212 Specialized Solutions.255. To keep things simple. instead of selecting the next subnet on our list.000 hosts each.255.Network + Training & Test Preparation Guide 4.224. Determine the Network IDs One you determine the number of subnets required and the subnet mask. the subnet mask would be 255. This will actually allow us up to 30 subnets with 2. Also notice that had we chosen 14 (no allowance for growth). let's look at the subnets for the subnet mask of 255.36.0 and the network address of 192. Count the number of binary digits (5). .248. For this example. Had we needed to add a new subnet.0. you can determine the available Network IDs.
36.96 192. For example.128 192. indicating that the Network ID is contained in the first two or three octets respectively.36. The sending computer checks the octets of the destination address against its own to determine if the destination computer is on the local network or a remote network. or one that is located on a remote network.001 in the last octet.36 (overall network address) 192.Chapter 8 – TCP/IP Essentials Subnets (Subnet Mask 11111111 11111111 111) Binary Network ID 11000000 00100100 11000000 00100100 001 11000000 00100100 010 11000000 00100100 011 11000000 00100100 100 11000000 00100100 101 11000000 00100100 110 Dotted-decimal ID 192.0.0 and the default Class C subnet mask would be 255.36.32 22.214.171.124. Summary of Subnets Subnet masks are used on TCP/IP networks to determine whether a message is for a computer that resides on the local network.0. A Class B network default subnet mask would be 255. they are on the same network.255. the sending computer will send the message to a router for delivery. (If the sending computer and the destination computer have the same subnet mask. In dotted-decimal format. 213 .160 192. up to and including the remaining digits not used with the subnet ID. This indicates that the Network ID is located in the first octet of the network address. The only restrictions are that you cannot use . these are reserved for broadcast addresses. If it is different.64 126.96.36.199. this means that the number starts with . Inc.36.000 or . on a Class A network the default subnet mask would be 255. The zeros indicate the location of the Host ID.) Specialized Solutions.192 Determine the Host IDs The host ID can be assigned as any number starting with the last digit of the forth octet (00000001).255.36. and continues up to one less than the subnet ID of the next subnet.
126 128 .0.Network + Training & Test Preparation Guide NETWORK CLASS CLASS A CLASS B CLASS C DEFAULT SUBNET MASK 255. Inc.0 255.0 255.255.0 CLASS ID 1 .0.0.255. .255.223 214 Specialized Solutions.191 192 .
On some screens. right-click on TCP/IP Protocol.Chapter 8 – TCP/IP Essentials TCP/IP Configuration Concepts The Windows Registry database contains the TCP/IP configurations. you will need to type in the specified default gateway. Click the radio button to enable DNS. other TCP/IP settings may be established or changed by first clicking on the Network icon in the Control Settings window. in addition to other hardware and software configurations. 215 . Use the "New" and "Add" command buttons to add a new gateway to the list of installed gateways. and click Properties." and the computer will capture one from the DHCP server. This opens the TCP/IP Properties window and you can now click on the appropriate tab and enter your configuration information. However. Next. IP Address Here. Default Gateway Type the IP address of the gateway routers you have installed on your network. you may specify a particular IP address. Specialized Solutions. Only administrators who have detailed knowledge and experience working with the Registry should attempt to change the default TCP/IP parameters in Registry Editor. and enter the information in the appropriate fields. or click the radio button next to "Obtain an IP address automatically. The appearance of these dialog boxes may vary depending on which operating system you are using. Inc. DNS You can enable or disable DNS. Whichever one appears first on the list is considered the default gateway. click the Protocols tab.
DHCP Dynamic Host Configuration Protocol (DHCP) is used on a TCP/IP network to send configuration data to clients. 216 Specialized Solutions. . Inc. It also includes the DNS configuration. WINS maps NetBIOS names to IP addresses.Network + Training & Test Preparation Guide WINS Windows Internet Naming Service (WINS) is central to Microsoft's networking topology. default gateway. This information includes the TCP/IP address configuration. and subnet mask configuration.
Inc. Keyword ARP BOOTP Class A IP Address Class B IP Address Class C IP Address Default Gateway DHCP DNS FTP HOSTS file HTTP HTTPS ICMP ICS IMAP4 IP IP Address LMHOSTS file NAT NetBIOS Octet Definition Specialized Solutions. Hint: There's a glossary in the back of this book. 217 .Chapter 8 – TCP/IP Essentials KEYWORDS Exercise Define each of the following keywords.
.Network + Training & Test Preparation Guide Keyword POP3 Port Number Proxy Server SMTP SNMP Subnet Mask Subnetting TCP UDP WINS Definition 218 Specialized Solutions. Inc.
What is an FQDN and give an example? 6. Who is responsible for maintaining top-level domains? 8. Inc. IPv4 addresses consist of a ______ bit number. Subnetting is the process of breaking an IP address into _________ and ________ groups. 4. What are five reasons to use subnetting? Specialized Solutions. 219 . How many primary protocols are used to make the TCP/IP Suite? 3.Chapter 8 – TCP/IP Essentials Review Questions Chapter 8 1. Name three of the five other protocols used within TCP/IP. 12. What is the purpose of DNS? 5. What are the four layers that make up the TCP/IP protocol suite? 2. What is the value of the leading bit (one on the far left) for a Class A IP address? Class B? Class C? 11. 10. What is a domain? 7. Which of the name resolution services will work only in Windows? 9.
.Network + Training & Test Preparation Guide 220 Specialized Solutions. Inc.
you can obtain several third party software packages that will help you manage a network. From the database and the software interface. The following are several SNMP managers: Hewlett-Packard Open View IBM NetView InterMapper (Macintosh) MRTG (Multi Router Traffic Grapher – UNIX) NetMinder Sun Net Manager SNMP utilizes three elements for the complete system: The management system software The agent software Communities Management Software This is the primary software package that is used by the administrator. the administrator can create reports and charts that define the status of the network. Inc.Chapter 9 – TCP/IP Utilities Chapter 9 – TCP/IP Utilities One of the advantages of using TCP/IP as your network protocol is that it comes with several utilities that you can use to validate and troubleshoot the network. Network Managers . The data is then compiled in a database called a MIB (Management Information Base). Using one of these products. you can remotely monitor any SNMP compatible device. Specialized Solutions. It is run on a single computer and is used to access any SNMP devices and collect data. 221 .SNMP Simple Network Management Protocol (SNMP) is an open protocol that allows third party software vendors to create products to manage networks. In addition.
Set: sends a configuration value to a device. Inc. This command will capture any errors and problems that occur on the agent device and send it to the manager.Network + Training & Test Preparation Guide Agent Software The agent software resides on the SNMP compliant device. therefore providing a level of security. These commands can be entered from a DOS prompt. Communities Communities are logical groups consisting of at least one manager and agent (usually several agents are assigned to one manager). The value of using communities is to limit the number of managers and agents. Get-next: request the next value in a sequence. Validation Tools TCP/IP provides several command-level tools that can be used to validate various parameters within a network. . An additional SNMP command is the trap. The three commands are: Get: request data from the device. A community can also restrict access. 222 Specialized Solutions. It will respond to commands issued by the management software.
Nbtstat -n provides local NetBIOS names. but did not cause a stop.Chapter 9 – TCP/IP Utilities Event Viewer Event Viewer is a Windows utility that will allow you to log any events and errors. Note in the graphic below that an icon indicates that the event is critical (a stop occurred). 223 . Nbtstat -R both purges and reloads the remote name cache table. and normal (i). shows every router interface that a TCP/IP packet passes through on its way to its destination. TRACERT A Trace Route command-line utility. Netstat -r shows the content of the routing table. Netstat -e shows Ethernet statistics. NETSTAT This command will display all the TCP/IP protocol statistics. and TCP/IP events and errors. This includes critical system errors. Specialized Solutions. NBTSTAT This command will display NetBIOS over TCP/IP statistics. serious (!). TRACERT. ROUTE The ROUTE command will show you the routing table and allow you to make edits to it. Inc. Nbtstat -c provides the remote name cache with the IP addresses. Netstat -s shows statistics on a per-protocol basis. Nbtstat -r provides names resolved by both broadcast and the WINS service. Netstat -a shows all connections and listening ports.
Inc. . clicking Run. and typing in either cmd or command. 224 Specialized Solutions.Network + Training & Test Preparation Guide Hint: Use these line commands by clicking the Start button in your taskbar.
IPCONFIG/WINIPCFG These commands are the same. and will display the current configuration of a computer. RARP RARP accomplishes the reverse of the ARP by using the known MAC address to find a host's IP address. Inc. Arp -s is used to change the IP address of a device. You should use this command when you want to verify a user's configuration or if there are problems reaching a remote host. NSLOOKUP This command is used to troubleshoot DNS problems and can display the DNS entry for a given IP address. For example.168. Specialized Solutions. and will often respond even when higher-level TCP-based services cannot. NSLOOKUP -h shows CPU and operating system information for the domain.Chapter 9 – TCP/IP Utilities TROUBLESHOOTING TOOLS TCP/IP also provides several useful troubleshooting tools. which might be 0000-05-67-FF-33. 225 . NSLOOKUP -d shows all records for the domain.1. IFCONFIG IFCONFIG displays the status of the network interface configuration. Ping -t performs a continuous ping and ping -n pings the IP address more than once. the IP of a host might be 192. NSLOOKUP -t shows all records of the type specified. Ping works at the IP level. Arp -a displays the current ARP entries (resolved IP to MAC addresses) on your client. PING The lowest level test to find out if you have connectivity to a remote host. IPCONFIG is entered from a DOS prompt and WINIPCFG can be used from RUN on the START menu. NSLOOKUP a shows aliases of clients in the domain. ARP ARP will allow you to find the physical address (MAC address) of a computer by using the IP address of that computer. and you would use this IP to find its MAC address or its physical address.12. The following three are the most common and are covered in more detail in the next chapter. NSLOOKUP -s lists well-known services of clients in the domain.
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Keyword ARP Event Viewer IFCONFIG IPCONFIG Management Software NBTSTAT NETSTAT NSLOOKUP PING RARP SNMP TRACERT Definition Specialized Solutions.Chapter 9 – TCP/IP Utilities KEYWORDS Exercise Define each of the following keywords. Inc. Hint: There's a glossary in the back of this book. 227 .
each device will need to be _________ compliant. You are the manager of a large network and have been getting complaints about the system being slow. TCP/IP provides several tools that you can use to validate statistics of your network. In order for your new network management software to monitor the activities of the entire network.Network + Training & Test Preparation Guide Review Questions Chapter 9 1. List as many as you can. Inc. 228 Specialized Solutions. . 3. What kind of software package can you purchase to help analyze your network? 2.
as well as the levels of permission necessary for these individuals to do their jobs. As you might have already deduced. she must develop a plan that will meet the needs of her particular network. or even millions. before you set up the network. or at least have your plan intact. Most network security breaches are the work of someone from inside the company. the results can be devastating. Specialized Solutions. Users should be held accountable for the security of their individual workstations. Once a company's files have been set up for maximum access. Select a basic security model that will meet the needs of your network and customize it as your needs change. creating chaos and costing thousands. motivated by curiosity. The best time to set up your network security. Password practices and procedures. Although corrupting and deleting files accidentally can cause serious problems. can deliberately damage your network. or an irresponsible prank. Whether the sabotage is malicious. and firewalls are critical parts of your network. There are a number of reasons for maintaining a secure network. Therefore. anyone can get into any file and do anything to it they want to do. data encryption. the network administrator has complete responsibility for anything that happens to the network. All users will have access to the network and to their own files (documents they themselves have created). A good plan will include the following considerations: • • • • Size of network Scope of network Type and amount of usage of the network Who will have access to what User-level Security All employees should be assigned user names and passwords.Chapter 10 – Network Security Chapter 10 – Network Security Security is a vital aspect of a network that cannot be ignored. 229 . you must also be prepared for the possibility of malicious intent. unless safeguards are built in. depending on the roles they play in your company. Very few users will have access to administrative features. A disgruntled employee. Inc. from wandering into unprotected areas and inadvertently corrupting or deleting files. or anyone who has access to your network for that matter. of dollars. User and Share Level Users will have different levels of access. Most users will also be able to access shared files. is right up front. Limiting access via passwords can prevent an inexperienced user. such as setting up E-mail addresses and initial passwords.
230 Specialized Solutions. Inc. the user will be inclined to be less attentive to personal security. Users can access a shared resource. should the administrator be unavailable at a time when administrator access is required. User-level security requires the user to logon using a Username and password. . A roadmap of all user names and passwords should be kept in a secure place. It creates an atmosphere of confidentiality. where the administrator can easily retrieve it. In a manner similar to the signature on a document. passwords are assigned to network resources rather than to users. However. such as a template or another type of file.Network + Training & Test Preparation Guide Privacy and confidentiality are important to most users. They can then copy the file to a local drive or a personal folder on the server. and cultivates a conscientious attitude toward security. Information on the shared drive cannot be changed by anyone other than the person who created the file. authentication confirms that messages received truly originated from their stated source. The user can edit the file as necessary. among other things. Password protection is. The systems administrator should have an assistant or backup person who will have total access to the system. a gesture of respect for the user and the system. the file can be accessed by anyone who has the password and knows how to use it to access the shared resource. User Logon Share-level Security With the share-level security model. while the original file remains intact. A verification method called "authentication" verifies the identity of a person or process. If the user is not able to trust that the documents he or she creates are safe from outside access.
Chapter 10 – Network Security Password Security Specialized Solutions. 231 . Inc.
if you wanted to block Internet traffic from entering your intranet. or they can be configured to suit your specific security needs.Network + Training & Test Preparation Guide Security Techniques There are a number of techniques and practices that will enhance the security of your network. Your security needs will determine which techniques will best meet your system's needs. and even more often on larger networks. Firewalls can trace calls and locate the computer trying to break in. A firewall will need to be part of your security plan in order to prevent unauthorized access from outside of your network. 232 Specialized Solutions. and your company's files and directories will be safe and available when you need them. It is an important part of a network security plan. They can permit or deny traffic at a certain level. you will be responsible for choosing the type of firewall that best meets your network's needs. Firewall Blocking Port Numbers You can block port numbers for security purposes on your firewall or router so as to allow only specific traffic into your network. and work at the application level. Inc. Some will be more suitable to your system than others. they can be host-based. Firewalls A firewall is designed to prevent access to your network from outside the company. Some firewalls will only allow E-mail to pass through. but they are not particularly effective if your goal is to protect trade secrets or other types of proprietary information. If you are accessing the Internet from your network. Files need to be backed up daily. at the very least. Backing up Data Another integral part of network security is your backup system. For example. you would block port 80. you will most likely be using E-mail. This needs to be handled in such a way that production will not be interrupted. Gateway hosts (also called bastion hosts) create fortified areas in the network's security perimeter. As the system administrator. or auditing. by forwarding application traffic through the firewall. Protocol-specific application proxy firewalls may provide increased access control. .
While planning your backup strategy. plan to fail. offer server equipment with multiple hard drives that mirror each other. Another more common form of backup is to a tape drive. so make sure not to neglect this important part of network security. Specialized Solutions. Nothing will save you time and stress like an effective and thorough backup strategy in case the worst happens and your system crashes. and how often backups will be performed. so if one goes down the other can maintain network operations. 233 . and are more commonly known as RAID. you must answer important questions about what to backup. called the backup medium. Ideally. These multiple disks are called disk arrays. This backup medium is suitable for small companies. Although slower than RAID. Backup Options Before we discuss the different RAID fault tolerance strategies. Inc. those who fail to plan. rather than one larger server. which uses laser technology to read and write information onto a removable disk that has capacities of 128 MB to 650 MBs. for performing and storing data backups: Removable Disks There are two categories of removable disks: Small-Capacity and Large-Capacity.Chapter 10 – Network Security It may make more sense to have two medium-sized servers. Floppy disk capacities today. how the backup information will be tested. Tape Backup This is probably the oldest and most popular backup medium in use today. range from 1. In addition. Most file server manufacturers recognize the need for data redundancy and thus. it is still a viable option. the other can take over without compromising network operations. The tape backup method is inexpensive and simple to implement. Remember. your plan will need to include information about who will be in charge of performing the backups. It also has large capacities of up to 50 GB for some systems. There are several options available. As you might guess. let's discuss the various backup methods that are available. If anything happens to one. the small-capacity category includes the floppy disk. Large-capacity disks include such options as the removable optical disk. the second server should serve as a backup to the first. and the procedure to follow for recovery. where you will keep the backup information (on-site or off-site).44 MB for the standard floppy disk to up to 250 MB capacities for ZIP disks. you know how important a backup plan is to the safety of your network's data. As a computer professional.
Most operating systems come with a backup utility. but usually these won't have the features available on a third-party backup program. The Incremental backup is used for daily backups. This method will take the largest amount of storage media. Inc. but will be the easiest to restore. Full. both the last differential backup tape copy and the last full backup tape copies will need to be used. . Differential and Incremental. This usually involves some degree of redundancy. It is a named portion or chunk of disk space. Fault Tolerance and RAID The ability of a system or component to continue normal operations. and utilizes different means of dealing with security issues at this level. This type of backup is usually performed weekly. Differential. 234 Specialized Solutions.Network + Training & Test Preparation Guide Back It Up Backup Software Software programs or utilities are available that make backing up data easier and more efficient. and Incremental Backups There are three backup types available: Full. Volumes Volumes are a way to organize storage disks so that the network operating system can store data on a disk. as its name implies. To restore. the last full backup and all of the incremental backup tapes will be needed. When recovering from a failure. despite the presence of hardware or software failures.. A volume can be part of a disk or an entire disk. as only the data that has changed since the last backup will be copied. The Full backup. This method also uses an archive bit to identify which files have changed. An archive bit is used to identify the files that have changed. is called fault tolerance. This will reduce the amount of time needed to perform backups to the server. The Differential backup is used for backing up only the files that have changed since the last full backup. will backup all selected data on the network.
and is a standard feature of RAID systems. administrators are alerted when one disk fails so that they can "regenerate" the RAID set before another disk has a chance to fail. Typically. 235 . if anything happens to one of the drives." Disk Striping (RAID 0) The segmentation of logically sequential data. a copy of the data is spread across all of the disks based on a mathematical formula such that any one disk in the set can be lost and the other disks will have a copy of all of the information that it contained.Striped array with rotating parity (disk striping with parity) NOTE: The acronym for RAID has also been referred to as: "Redundant Array of Inexpensive Disks.Chapter 10 – Network Security The following are common RAID (Redundant Array of Independent Disks) specifications: RAID 0 . Inc. however. so that segments can be written to multiple disk drives (or other physical devices) in a round-robin fashion is called disk striping.) Disk Mirroring (RAID 1) Disk mirroring or disk duplexing involves using one or more mirrors of a hard disk. then the data in the entire array is also lost.Mirrored arrays (disk mirroring) RAID 2 . RAID 6 and Beyond RAID-6 includes a second disk striping with parity scheme. is not being used commercially at the moment to an Specialized Solutions. If your processor is capable of reading or writing data faster than a single disk can keep up. including Novell NetWare. However. (Provides no fault tolerance.Striped array with parity (disk striping with large blocks) RAID 5 .Non-redundant striped array (disk striping) RAID 1 . If more than one disk is lost. such as a single file. This. support either disk mirroring or disk duplexing. Disk Striping With Parity (RAID 5) The most common of RAID strategies. which provides for even more fault tolerance.Parallel array with parity (disk striping with ECC stored as parity) RAID 4 . the data in the stripe set is lost and cannot be retrieved. The same data is written to two separate hard disks in order to preserve the data in the event of a device failure. Several operating systems. this relatively inexpensive technique can be very useful. With this method. This technique may be applied in either software or hardware. this one uses the parity method of ensuring that the data stored is really the same data that was sent.Parallel array with ECC (disk striping with ECC) RAID 3 .
and each type provides power for a different length of time. Storage Area Network (SAN) A SAN (Storage Area Network) is a back-end network connecting storage devices (generally by using SCSI). In this case. SANs are channel attached whereas NASs are network attached. but it is treated just like any node on the network and is subject to all the positives and negatives of that identity. and sags in the power supply. are power strips that provide protection from voltage spikes. . surges. Inc. as you might guess. and guaranteed to provide power to a computer in the event of interruptions in the incoming electrical power. There are several tools on the market that will help prevent data loss from power fluctuations. is an issue. allowing the computer to shut down before complete loss of power. it offers better performance. A centralized SAN generally ties many hosts together into one storage system. Fault Tolerance and Power You need to protect your network from data loss due to power surges and failures. is like RAID-10. Like RAID-10. such as battery time remaining. A SAN can either be centralized or decentralized. also called surge suppressors. It functions faster. An Interactive UPS (also called an "intelligent UPS") connects to the computer's serial port and provides information. since it is not dependent on another computer. but uses a striping scheme where each stripe is a RAID-3 array of disks. A RAID system is the most common example of a centralized SAN. There are different types of UPS devices. RAID-10 is comprised of an array of stripes (each stripe equals a RAID1 array). which allows for better performance. Surge Protectors Surge Protectors. Network-Attached Storage Network-attached storage (NAS) is hard disk storage (RAID) like SAN. The equipment described below is among the best available: UPS (Uninterruptible Power Supply) A UPS is battery powered. It also has a bare-bones OS (microkernel) for processing I/O requests. the best tools seem to be the more expensive ones. It is assigned an IP address and it is attached to a LAN. SAN traditionally have been used for the purposes of archiving data that is needed but infrequently used.Network + Training & Test Preparation Guide large degree. but at a greater cost. Cost. A decentralized SAN connects multiple hosts with many storage systems. RAID 7 offers a real-time operating system and the functionality of a standalone computer. 236 Specialized Solutions. These types of RAID are not as commonly used and are not as likely to be on the test. RAID-53.
management must randomly check to make sure that the policy is being applied. symbols. should be given the opportunity to look through another person's desk while they are not there. and troubleshoot before the trouble starts. but most networks can get by with changing their passwords every 30 days. So. and numbers. 237 . There is no reason for anyone other than the user to access the user's files. The most effective passwords are ones that are the maximum number of characters and use a combination of letters. Some "classified" networks require password changes every day. no matter who they are. etc. Evaluate your security policy on a regular basis to ensure that it is up to speed. numbers and symbols. In order for this policy to be effective. Users working with sensitive information such as budgets. but are easy enough that users can remember them. away. he or she will know how to accomplish the task. This is known as a security audit. Specialized Solutions. an effective password policy is one in which passwords change on a regular basis. Passwords should be changed more frequently in high-security networks.Chapter 10 – Network Security Password Practices and Procedures A network administrator may encrypt password information that is automatically sent to the server when users log on to the network. No one. This holds users accountable for their actions on the network. Policies that spell out password procedures should be given to all users so they will know what is expected of them. If the network administrator needs to use the workstation. Inc. so why make them available by not cleaning off your electronic desktop when you leave your workspace? Many large companies implement a "clean desk policy. Password security is compromised if a user writes his or her password down where it might be seen by others. The importance of users logging off and locking their workstations when they are not physically using them cannot be stressed enough. and discourages them from wandering into unauthorized areas." What this means is that if the employees leave their workstations (for any reason) they are required to clean off their desks or workstations and lock documents. include characters. personnel records and other confidential data should change their passwords at least every 30 days.
Encryption is used to scramble passwords on an internal network so that they may not be stolen during logon. Encryption converts regular text into ciphertext by combining the original data with one or more "keys" known only to the sender and recipient.Network + Training & Test Preparation Guide Encryption Data can be encoded at the sender's end and decoded at the recipient's end so that no one. Encryption is also used to encrypt E-mail transmissions. RSA (Rivest-Shamir-Adleman) uses both a public key and a private key. It was invented in 1977 by Ron Rivest. Inc. A VPN is a network that uses the Internet to connect remote users to an internal network. Without encryption the Internet would be a hotbed for high-tech thieves who could tap into it and steal information and credit card numbers. can understand the message. and Leonard Adleman. and is used extensively for online commerce (e-commerce) and online banking. The entire security of RSA depends on the difficulty of factoring large prime numbers. . and the recipient's private key is used to decrypt it. 238 Specialized Solutions. This practice is called cryptography and the system is called a cryptosystem. Adi Shamir. DES (Data Encryption Standard) is the fastest and easiest method of sending an encrypted message. the Internet is not the most secure of environments. Even with encryption. The recipient's public key is used by the sender to encrypt the message. RSA is a public-key cryptosystem for both encryption and authentication. DES was developed by IBM and is now the most commonly used Private Key encryption system used. The name comes from their first initials. because the sender and receiver use the same key to decrypt the data. These keys are numbers or strings of characters combined with the original text to create an algorithm. It is also used to secure data over VPNs (Virtual Private Networks). This method uses a 56-bit private key. other than the person for whom the message was intended.
it is not a completely secure encryption method. software from unknown origins. which identifies and authenticates the sender and message data using public-key encryption. Many viruses are simple annoyances. much less a day. and bulletin boards. If the receiver wishes to respond. Since the financial impact on a business can be severe if even down for an hour. so as to allow the business or organization to quickly resume their activities.Chapter 10 – Network Security Extra data appended to a message. but the use of the 80-bit key makes it much more complex. will ensure a much quicker recovery. The sender encrypts the message using a public key and the receiver decrypts it using a private key. Viruses Viruses are those nasty little programs that can wreak havoc on a computer and its data. Inc. EES (Escrowed Encryption Standard) is known as skipjack and uses an 80-bit key. PGP (Pretty Good Privacy) is based on Public Key encryption and was developed to encrypt E-mail messages. Most viruses are written by hackers who are trying to show off. but they are less secure. It is similar to DES. which is used to encrypt data and to decrypt it. With this method of encryption both parties have the same key. Prevention should also be addressed in the plan. There are over 60. files downloaded from the Internet. but some of them can cause irreparable harm to files. both on location and at backup sites. It should keep the mission-critical functions first and foremost. Public Key encryption uses the Diffie-Hellman algorithm and is a one-way type of encryption method. There are four basic types of viruses: File Infectors: These attach themselves to executable files and spread to other files when the program is run. it is imperative that all possible disaster scenarios be addressed. It is designed to offset or minimize the effect of a potential disaster on the business or organization. 239 . the message is encrypted using the original sender's public key. Skipjack was originally designed to be integrated onto a chip known as a clipper chip. Symmetric Keys can also be used. The sole purpose of a virus is to replicate and make life miserable for computer users. Boot Sector: These replace the master boot record (or boot sector on a floppy).000 known viruses. Viruses can be spread by various sources including: shareware. The recipient of the response would then use their private key to decrypt the message. Ensuring the integrity of your network infrastructure to the best of your ability. Disaster Recovery A disaster recovery plan (DRP) lays out how an organization or business is to deal with disasters. Specialized Solutions. They will write themselves into memory any time the computer is booted. As the name implies. is called a digital signature.
especially if they come from sources other than a manufacturer's Web site. Keep your anti-virus program updated.Network + Training & Test Preparation Guide Trojan Horses: These appear to be legitimate programs. Hundreds of viruses are written each month. Many viruses are transmitted by floppy disks. Unfortunately while macros are very valuable. Trust no one when it comes to loading programs on your machine. they mean that when you open a document you are running a program. Inc. If the computer has a BIOS setting that allows you to disable boot-sector writes. 240 Specialized Solutions. Unfortunately viruses have become a way of life in the computer world. With this in mind. just from running a program. (They can also attach to some kinds of E-mail). Make sure it is compatible with all of the operating systems that you use. but when loaded. . The most secure protection against Internet-distributed viruses is to make sure you have an antivirus program running at all times (or at least when you're downloading and first running new files). These days. many viruses and macroviruses are transmitted over the Internet. Macro Virus: These attach themselves as executable code to documents and run when the document is opened. they will go to work on the system. Be careful when reading floppies of unknown origin or using your disk on unfamiliar machines. enable it! This setting must be disabled before installing a new operating system. (prevents applications from writing to the boot section of the hard disk). there are several measures you can take to prevent or at least minimize the damage: Purchase an antivirus program—there are several good ones on the market. Use extreme caution when you download files. It used to be true that you couldn't get a virus from opening a document.
Inc.Chapter 10 – Network Security Specialized Solutions. 241 .
Inc. Keyword Data Encryption Differential Backup Disaster Recovery Disk Mirroring Disk Striping Firewall Full Backup Incremental Backup NAS Password Security RAID SAN Share Level Security User Level Security Volumes Definition 242 Specialized Solutions. Hint: There's a glossary in the back of this book.Network + Training & Test Preparation Guide KEYWORDS Exercise Define each of the following keywords. .
Chapter 10 – Network Security Review Questions Chapter 10 1. What purpose does encryption play in your security model? Specialized Solutions. What are the two requirements of user level logon? 2. 3. 5. 243 . passwords are assigned to __________. Inc. What are the three common levels of RAID? 6. In a share level model. What is the function of a firewall? 4. The acronym RAID stands for __________.
Inc.Network + Training & Test Preparation Guide 244 Specialized Solutions. .
"as reported. For some technicians troubleshooting comes naturally. This chapter will begin with some basic troubleshooting techniques. They always fail in the middle of a job. you must be organized. while for others it is a struggle. establish what has changed. not the symptom. To make matters worse. Basic Troubleshooting As mentioned. In order to do this. It is proper use of all the parts that will make your next troubleshooting exercise easier. Inc. a pen (or pencil). and good listening skills. As a troubleshooter. The first step is the most critical and often the most ignored. test the result. but they often hold the keys to the problem. The majority of this course has focused on the facts and science of networks. Be sure to listen carefully to your client or co-worker. so that you can focus on the things that might be the cause of the problem. implement a solution. This added frustration often leads to confusion and stress." is really just the symptom and not the true cause. This chapter will focus on the application of these facts to solve problems. Don't assume that just because you are the expert. or when there is a deadline and the user must have it fixed now.Conclusion Chapter 11 – Troubleshooting a Network Being a computer and network professional automatically implies that you are a troubleshooter. identify the affected area. you must be able to quickly and confidently eliminate as many alternatives as possible. Specialized Solutions. Remember. troubleshooting comprises perhaps the single largest aspect of working with computer and network hardware and software. troubleshooting is more of an art form than a science. The eight parts are as follows: establish the symptoms. not when all is well. and progress with some specific tools that you can employ to simplify the process. 245 . Being an effective troubleshooter does not come automatically with networking knowledge (even though it is implied). the operator doesn't know what caused the problem. If fact. computers never fail at a convenient time. In most cases. Let's take a look at an eight-part approach that will lead to successful troubleshooting. What you must learn is how to approach a problem in an organized and methodical manner. recognize the potential effects of the solution and document the solution. The user of the computer or network is your best source of information. you are looking for the cause. Troubleshooting is an art and can be learned. Establish the symptoms: Defining a problem is not always as simple as it sounds. if you are the expert. a habit of applying a methodical and determined approach will soon result in it becoming second nature for you. The only tools required for this phase are a pad of paper. For those who must endure the struggle. Remember. select the most probable cause. Without a complete understanding of the problem (the entire problem) you can spend a great deal of time working on the symptoms instead of the cause. it seems well defined by the person who calls and complains! But is it really defined? Frequently the problem. you will most likely be called when there is a problem. After all. They may not know the technical reason for the failure.
and most importantly. you have isolated the problem to the keyboard or its cabling. screen changes. If possible. however. Establish what has changed The most difficult problems to isolate are the intermittent ones. Do not make the questions too technical. This will take time and patience. network or computer moved. do not intimidate the user. Ask a few questions to help identify the problem and list the events as they occurred before the failure. Are you the only one having the problem? Did anyone else use this computer? The list of questions could go on forever. the failure occurs. lights. have to ask some specific questions to jog their memory. The purpose is to narrow the search down to one or two general categories.Network + Training & Test Preparation Guide you may know how the computer and network runs and can find the technical cause of the failure. You may. recent software upgrade. as well as the results. You may want to create a form with these questions (and others specific to the situation) for taking notes: When did you first notice the problem? What has changed since the computer was last used? (New Software. have someone demonstrate the failure to you. Isolating the problem is the art of eliminating what you know from what you don't know. Describe any changes in the computer (noise. if a keyboard is not working and you connect a known good keyboard to the computer and it works. You will need to create your own list based on the situation. One thing that might 246 Specialized Solutions. If it is an operatorinduced problem. the process of elimination is all that you can do.) Show me how to create the error. it is important to observe how it is created. but the operator was there before (and after) the problem started and may recall the events that led up to the failure. and when. Be sure to observe the failure yourself. you will be able to identify the best questions for the situation. There is no particular approach to follow and there is no substitute for experience. or help them focus on what was going on when the problem first occurred. Sometimes. With a little experience. . For example. and so forth). These never seem to occur when you are present. Inc. The only way to resolve these is to be able to re-create the set of circumstances that caused the failure. The best you can do is to eliminate any obvious problem and work toward the more complex. The user will need to keep detailed records of what is being done before. Identify the affected area The next step involves the process of isolating the problem.
That way the "evidence" is not disturbed. create a new plan based on what you discovered with the previous plan. Document every action and its results. is the problem occurring on more than one workstation or is it only on one? If you determine that the problem is only on one workstation and the cabling and network card are working properly. the first step in isolation is to separate a network (hardware) problem from a workstation problem. You may have to refer back to them later. Starting from the top. Start with the most obvious or easiest solution to eliminate. then you need to further isolate the problem to determine which program is experiencing difficulty. Be sure to refer to any assumptions you may have made. Select the most probable cause Make a Plan and Follow it from Beginning to End Create a planned approach to isolate the problem based on your knowledge at this point. In the case of a network problem. Write down your plan! The first step of any plan should be document and back up. write them down. For example. then you know for sure that the network is physically working. 247 . The general procedure for isolating network problems is to start globally and work to locally. If the first plan is not successful (it won't always be). and move forward. make a plan and follow it. If you must make any assumptions. Inc. It requires two simple steps. isolate the problem to: A WAN or LAN A segment of a LAN A workgroup or domain A server or workstation A workstation or user Specialized Solutions. Isolation of a problem requires a structured approach. Do not make any assumptions. it is important to follow it through. If for example.Conclusion help in such cases is to tell the user to not do anything with the computer when the problem recurs. but to call you. you can "see" other computers in the network neighborhood. Jumping around and randomly trying things can often lead to more serious problems. Once a plan is created. but you cannot receive any E-mail. but something must be wrong in the E-mail software or configuration.
Confirm that the operator is using standard operating procedures. Test the correction (make sure that the changes work). Inc. To resolve these types of problems. This means to have the operator duplicate the problem while you watch – do not tell them how. be sure to record the "before" and "after" changes. Resolving operator-induced failures is more difficult than hardware induced failures. if an operator is afraid of computers in general. This will keep you removed from the problem and eliminate the "it always works for the expert" syndrome. For example. 248 Specialized Solutions. either repair or replace the defect. you must be very careful to treat the cause and not the symptoms. repair or replacement is usually all that is needed. no amount of training or instruction will solve a problem until that general fear is removed. Here are a few suggestions for isolating the hardware/software from the operator: Have another operator perform the same task on their own workstation. as well as the one that is causing problems.Network + Training & Test Preparation Guide Once the search has been narrowed. start looking for specific hardware: Routers Hubs/Concentrator Cabling or Connections Adapters Software related problems could also be isolated to several causes: Protocols Authentications As often as not. In these situations. Implement the solution. you must be careful as to how you resolve the problem while not alienating the operator. Implement a solution After locating or at least narrowing the problem to a few possibilities. It is important to use another operator. Frustrated and confused operators can lead to further problems. . if the problem is software or configuration related. With hardware. and not the hardware or the system. In these cases. you must do three things: Formulate a correction (write down what you think will resolve the problem). Note: If the problem is software-oriented. However. the problem may be caused by the operator. it may require some additional effort.
You must look at every new problem as an opportunity to expand that experience. This is one way to build. Specialized Solutions. This means to document (in writing) the symptoms. Inc. The reality is that the time you spend after the repair can save repeat service calls and shorten the time-cycle for future service calls. you are wasting your time and should be working on the next problem. there is no substitute for experience. Confirmation means to make sure that the problem no longer exists. Confirmation of the repair can save you a return trip to repeat the fix or to correct a problem that you created. Test the Result No repair is complete without confirmation that the job is done. document the problem and the repair. Keeping a copy of the repair procedure in your technical library may come in handy in a year or two when the problem (or one like it) happens again. and the repair. Many troubleshooting and repair services operate on the fix and run principle.Conclusion Now we want to separate the true professional from the amateur. and share experience. Document the solution Finally. The basis for this policy is that once the system is running. You have not done a professional job if the repair was completed at the expense of something else. or a follow up call just to make sure all is well. maintain. Recognize the potential effects of the solution Make sure that the fix did not create other problems. In troubleshooting. 249 . the problem. Confirming the repair may include some form of feedback from the user. Ask the user to test the solution and confirm satisfaction.
Wire Crimper Punch Down Tool Punch down tools are used to "punch down" cabling to "blocks" in your wiring rack. They secure the connection between the wires and the block. let us quickly cover some tools used to setup the network cabling. . Hardware Networking Tools Before we get into the tools that are designed specifically to troubleshoot and ensure the integrity of your network. Networking tools can be divided into two categories: hardware tools and software tools. Inc. Wire Crimper The wire crimper is a versatile tool that strips and cuts copper wire as well as crimping solderless terminals.Network + Training & Test Preparation Guide Networking and Troubleshooting Tools Just like a good computer repair technician. The narrow nose with its serrated jaws is used for pulling or coiling wire. a network troubleshooter will need a few tools to make the process of troubleshooting easier. Punch Down Tool 250 Specialized Solutions.
The Multimeter The name multimeter was derived from its ability to measure several different parameters. A shorted conductor means that the current is flowing to ground or another cable instead of being isolated. the resistance reading for continuity would be zero – meaning that current is flowing without resistance. When you connect both leads of the meter to each end of the device you are testing. We will start by looking at a multimeter. Since it is made up of wires. Most will consist of a digital or analog meter or display. For example.Conclusion Hardware Troubleshooting Tools Hardware troubleshooting tools are used to confirm the integrity of the cabling. which will indicate a complete circuit by either a light or a sound. Media Tester Media testers are usually devices used to test the cabling. You can test for AC and DC voltage. but only low amounts (less than 10 amps). a pair of wires with probes (one black and one red). When working with network cabling. and a switch for adjusting the range of settings to be measured. A bad cable will be either open or shorted. These failures are like a water pipe that is broken (open) or has a leak (shorted). If your meter does not have a continuity setting. the resistance reading will be infinity or maximum – meaning that no current is flowing. and continuity. it is to check to see that a wire is not broken. resistance. The red wire is the positive probe and the black wire is the negative or ground probe. a positive test (the light comes on or it makes a noise) means that the circuit is complete. An open conductor means that the cable is broken and the current will not flow from one end to the other. 251 . They can check for continuity and how the pin outs line up. In a wire for example. Most multimeters have a "continuity" setting. very easy to troubleshoot. Some meters will let you test for current as well. These devices are generally used when you make your own cabling. There are several tools we can use to check for open and shorted wires. All you need to do is use the resistance setting and test the device. it is still possible to test for continuity. If the wire is broken. Specialized Solutions. in principle. Inc. as well as the electrical power in the computer. Network cabling is. With it you can test various electronic components. A good cable will provide continuity or current flow from one end to the other. whether it be RJ-11 or RJ-45. the circuit is broken. you can have only one of two problems. If the test is negative (no light or noise). which is one of the most basic tools for electronic troubleshooting. The purpose of continuity testing is to confirm a complete electrical circuit. we will have to know how to test for continuity.
This applies a signal on the wires. called tone generators and tone locators. and test at the other end. testing for continuity will require an additional wire. Telephone and phone wiring companies use two tools. You can use a pair of wires (very common in network cables) and connect the two wires at one end. . this is not a problem. 252 Specialized Solutions. thus locating the wires. However. Inc. When used together. if the cable is a hundred feet long and spans the length of a building. The problem when using this tool for testing continuity of a network cable is the length of the cable. If both ends are in the same location. However.Network + Training & Test Preparation Guide Network Tester Tone Generator and Tone Locator A multimeter is a universal tool and almost any electrical or electronic technician should have one. When the receiver is placed in close proximity to the wire that has the signal applied. these tools are often called a fox and a hound. The tone locator is a receiver that is set to the frequency of the generator. several pairs of wires at one end (the hub or patch panel). The tone generator is connected to the wires at the known location (the room with the outlet). to find pairs of wires in a bundle. The question then becomes which pair goes to which room? Solving these problems with continuity testing can take a long time unless you are just lucky. there are more often than not. it will emit a tone.
Specialized Solutions. are usually a PC with a special network card. These cables can be used to connect two computers into a single network eliminating any other network hardware. 253 . Be careful when using a crossover cable. If you are able to send a signal and have it return. the location of any break or short can be determined. Inc. capture packets and generate reports. Protocol Analyzer A protocol analyzer is used to monitor and analyze network traffic. By calculating the time it takes a signal to travel the length of a cable and to be reflected back. The transmit wire on one connector is connected to the receive wire on the other (and vice versa). A crossover cable is similar to a loopback. also called packet sniffers. Any signal placed on the transmit wire will loopback to the receive wire. The Time-Domain Reflectometer (TDR) is used to find breaks and shorts in network cabling. but is double-ended.Conclusion Tone Generator Test Cables One method of isolating problems is to use a special cable to remove a workstation from a network and simulate that it is still connected. you will know that the network card and the protocol stack are functioning. Time Domain Reflectometer For those who are serious network troubleshooters. It has the transmit and receive wires connected. there are advanced tools that may well be worth the time and investment. and therefore back to the network card. Many protocol analyzers will include a TDR as one of their functions. because they look just like patch cables but are not interchangeable. They will monitor network traffic. Software analyzers. Two such cables are the hardware loopback and the crossover cable. A loopback cable is just what the name implies. It is a single-ended cable that connects to a network card.
Inc.Network + Training & Test Preparation Guide Optical Tester Optical Testers or optical time domain reflectometers (OTDR) are essentially the same as a TDR. OTDRs also calculate the locations of breaks by the amount of time it takes for a signal to travel the length of the cable and back. . but used for fiber optic cabling. 254 Specialized Solutions.
The following table provides some generic troubleshooting concepts: Network Troubleshooting Situation A single workstation does not connect to the network. If data transfers are incomplete or inaccurate. This is sometimes called a broadcast storm. 255 . Anything that breaks the integrity of the data on a network is a break of security. or a disk resource. check to ensure all network cabling and connectors are intact. A bottleneck is any resource that limits the rate at which network traffic can be moved. Some passwords are case-sensitive. the traffic is not moving. due to either excessive traffic or a bottleneck. It could be the processor. Inc. Reduced bandwidth is just like a traffic jam. You can't access a resource unless the administrator of the network has allowed you to do so. Common mode failures are generated when one component of a LAN causes the entire LAN to fail. you will need to refer to the operating systems' manuals for detailed troubleshooting procedures.Conclusion Maintaining and Troubleshooting Networks Maintaining and troubleshooting networks differs from operating system to operating system. An example would be a network card that begins to continually broadcast useless information and overloads the network. Authentication Probable Cause Usually these are authentication errors. but can be caused by a disconnected cable. For some reason. Therefore. Common Mode Failures Loss of Data Network Security Violations (Insufficient Rights or Permissions) Reduced Bandwidth Specialized Solutions. A common failure is for a user to be unable to logon. and a stuck caps-lock key can cause errors. Often these are caused by typos when entering user names and passwords. the network.
check for memory bottlenecks. Traffic Overloads Unauthorized Software 256 Specialized Solutions. When the amount of traffic exceeds the ability of the network to carry it. If slow loading persists even after defragmenting. . and moves information. You must defragment the drive. As networks grow. deletes. You must manage software distribution to ensure users are not loading non-licensed software and computer viruses onto the network drives. tasks like backing up drives or moving large amounts of data can be done at night. so does the traffic. Inc. For example. These problems can be addressed by segmenting the network and scheduling non-critical work for after hours. the network slows down.Network + Training & Test Preparation Guide Slow Loading of Programs and Files Fragmentation occurs when the operating system saves.
and TRACERT commands to test the network. because as a network professional. TRACERT allows you to trace the "hops' (routers encountered) that a packet takes to its destination. Specialized Solutions. you can confirm your hardware and protocols by using the IPCONFIG. On a Windows 95/98 computer. but looks better and includes the MAC address of the network adapter card. This command will give the same results as IPCONFIG from DOS. 257 . It also lets you know the time that it takes.Conclusion Troubleshooting Scenarios The following summarizes some possible scenarios that you may encounter and how to provide a solution: Misbehaving Protocols You have just installed a new workstation and are unable to see any other workstations or servers on the network. you can use the WINIPCFG command from the RUN dialog box in the START menu. Remember this address.0. The loopback address is 127. If you are using TCP/IP. PING.1. The first step is to PING the loopback address. On a Macintosh system. you will use it often. This comes in handy if you need to see where exactly on your intranet or on the Internet your packet is going.0. This will test the protocol stack in the computer. These commands work from a command prompt. open the TCP/IP Control Panel to use these utilities. Inc. PING the Loopback Address The next step is to use IPCONFIG to get details about your workstation.
or 2003 system. If you are using Windows. WINIPCFG You can now PING that address to determine if the network card and protocol stack for the computer are working properly.55. . 258 Specialized Solutions.48. This command is only for Windows 9x and ME and will not work on a Windows NT. WINIPCFG.Network + Training & Test Preparation Guide Notice that the IP address of this computer is 195. your dialog box will look like the following.6. Inc. 2000. XP.
Inc. and so on.Conclusion PING 195. you will be testing a larger portion of the network.6 Continue the process by PINGing another workstation.48. or the computer you are PINGing is not using the TCP/IP protocol. use the ipxping command. Poor connections and loose connectors cause most cable problems. you receive a message like the following. For the IPX/SPX networks. With each step. The biggest problem with them is that we often assume that since they worked yesterday. Usually this means you have the wrong IP address. Cable Problems Cabling problems are simple: either they work or they don't. you have encountered a problem. the server. PING Found a Problem If you are unable to reach a host computer. If at any stage. then there is a problem with the protocol.55. Here are some suggestions when you suspect cable problems: Specialized Solutions. It could simply mean that it is not logged on to the network. they must be okay. 259 .
NIC Indicator Lights Many network cards have from one to three LED lights (green or yellow) next to the cable connector. How do you determine the problem? One network problem encountered is name resolution. Replace any suspect drop or patch cables with a known good one.Network + Training & Test Preparation Guide Any time a computer was moved and it suddenly stops responding to the network. Earlier. Performance You think that your network is performing without problems. The difference between HOSTS and LMHOSTS is that HOSTS is used in place of DNS and LMHOSTS is used in place of WINS. If these files are being used. we need to look at four limiting factors on performance. they will let you know if the card is working and if it can access the network. If no lights are on. In general. That location is the DNS (Domain Name Server). Inc. we learned that workstations. The actual function of each light will depend on the manufacturer and you may have to check the documentation that came with the card for details. the first thing to do is find out what has changed. you can find them on the host in the systemroot\system32\driver directory. Name Resolution You are testing a new workstation and are unable to see the workstation by its domain name." With nslookup. you will need to use a TCP/IP utility called "nslookup. These lights can be seen from the back of the computer. have two names. To resolve this problem. or hosts. These are text files that are used to statically map local and remote hostnames and NetBIOS names to IP addresses. Any new hardware or applications (including upgrades) are always good candidates for the problem. suspect a loose or disconnected cable. You know that the IP connection is good because you can PING the IP address. If present. Beyond that. If there is a sudden change in performance. but are starting to get complaints that "the network is slow. Somewhere in the system is a table or database that provides the translations from number to name and vise versa. One is the IP address number. while green lights indicate that all is well. Check the indicator lights on the adapter card. . you can be sure that the network is not being detected. 260 Specialized Solutions. (which the computers like) and the other is the IP address name (which we humans like). you can connect directly to the DNS and access the information stored there. Another place to look for name resolution problems (on a local LAN) is in the HOSTS and LMHOSTS files. respectively." What are you going to do? These problems are often difficult to resolve because there are a vast number of possibilities as to the cause. they will indicate whether or not the card can detect the presence of a network and when data is being transmitted.
if you are experiencing slow printing. or maximum speed that traffic can move. after you identify the problem. A server with a memory deficiency will have to write information to a disk cache. Specialized Solutions. some network operating systems will allow for burst mode operation. you can print the same document at different times throughout the day and record the time it takes to print. slow. A baseline is simply a record of performance criteria at a given time. Therefore. everything slows down. at a later date. Think of the bandwidth as the number of lanes on the highway (the more lanes. but can be measured and will affect performance in large networks. is the throughput and is measured in Mbps (Megabits per second). are negligible. you will need to run a series of tests and record the performance. A server that is operating its CPU at 100% will have to delay processing of each request until it completes its current request. for the most part.Conclusion Bandwidth and Throughput Bandwidth and throughput are not the same thing. if any one component is performing poorly. For example. Latency delays. Reading and writing from a disk is much slower than from memory. This may require the requestor to continue to resend its request. Just like our highway. it can send data at a faster than rated speed. The trick is knowing how the network performed when it was good and how it performs now. To create a baseline. From this information. 261 . the more packets that can be moved). but are interrelated. Routers and switches that connect any two segments of a network can cause these delays. it will affect the entire network. You can think of a network as a super highway and the vehicles as being packets of information. Inc. An application will have to be designed to take advantage of burst mode in order to use it. The answer lies in creating a performance baseline. This can slow down data transfer. Then. Server/Workstation Limits Nothing will slow down a network more than a sluggish server. Resolving performance problems can be easy. you will know the high. The speed limit. and average time to print the document. For example. This means that for a small amount of time. The bandwidth is the number of packets that can move past a point at any given time (also measured in Mbps). Latency Small delays in packet movement that are caused by devices is called latency. Application Efficiency Any application that was not designed to work over a network will be unable to take full advantage of network protocols. if the traffic gets too congested. you can re-test the printer performance under the same conditions and determine if things have changed. adding to the network load. The performance of a network will only be as fast as the slowest link in the entire system.
you will be able to monitor such events as processor time. With this activated. Windows has a built in performance monitor as part of its administrative tools. percent of network utilization.Network + Training & Test Preparation Guide The key to monitoring network performance is statistics. Inc. Windows Performance Monitor 262 Specialized Solutions. Network statistics will come from two sources – the server and the network. With this tool. . etc. available memory. you can monitor and collect data for a variety of events. Similar software packages (usually as part of a network analyzer) will collect data for packets/sec. etc. you will need to use some software called performance monitor for the server or network statistics software for the network itself. To collect these statistics.
Keyword Bandwidth IPCONFIG Latency Media Tester Multimeter Performance Monitor PING Punch Down Tool TDR Throughput Tone Generator Tone Locator WINIPCFG Wire Crimper Definition Specialized Solutions. 263 . Inc. Hint: There's a glossary in the back of this book.Conclusion KEYWORDS Exercise Define each of the following keywords.
What are the three primary steps to take when troubleshooting? 2. What would be the best tool to help you locate the cable in question? 4. What utility can you use to confirm that the protocol stack is good? 6. and think it might be shorted. You have just connected a workstation to the network. but need to know which of the 50 cables goes to the accounting office. What is the difference between bandwidth and throughput? 10.Network + Training & Test Preparation Guide Review Questions Chapter 11 1. What TCP/IP utility can you use to find the IP address of the workstation? 8. . You need to know the IP address of a workstation. What is the easiest way to tell if the network card can "see" the network? 9. What tool would you need to find the short? 5. What is the loopback IP address? 7. What utility can you use to determine the performance of the server? Conclusion 264 Specialized Solutions. You have found the cabinet with the patch panel and hub. You have a Windows 2000 network and received complaints that the server is running slowly. You are troubleshooting a cable problem. Inc. After repairing a problem. You have located the cable in question #3. You are working with a TCP/IP network and want to confirm the protocol stack in a specific workstation. are you finished with the troubleshooting process? 3.
as you like. be sure to refer back to the beginning of this book for tips on what to expect at the exam site. To measure your retention of these materials. or if you just want to let us know how you are doing. and as often. After taking a practice exam. When you are consistently achieving scores in the 90% range. start taking the practice exams that are on the CD-ROM that was included with this course. be sure to review any areas that need improvement. When you are ready to schedule your exam. you are ready to sit for your certification exam. so if you have any questions. Specialized Solutions. 265 . The following "Appendix A" is an excellent source of review material. the best thing about a self-study course is that you are able to review it as much. We hope that you have enjoyed your Network+ training journey as much as we have enjoyed providing it to you. Inc. we'd be happy to hear from you! Remember.Conclusion This concludes our Network+ Training & Test Preparation guide. Remember. We love to hear from our students. at Specialized Solutions. Thank you for allowing us to be your training partner and please let us know if we can help with any of your future training needs. and don't forget to use the Glossary. our success is directly tied to the success that our students have with our training and certification products.
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Coaxial Cable Types Not all coaxial cables are the same. 267 . all electronic components must operate at the same impedance. It is expressed in ohms. Using the wrong cable will cause poor performance and/or failure of the network. you must conform to the 5-4-3 rule. Only 3 segments can contain nodes. Impedance is a unit of measurement for resistance to AC voltages. They are specified based on their impedance.Appendix A – Tech Summary Appendix A – Tech Summary The following tables summarize key information found in this course: 5-4-3 Rule When installing coaxial Ethernet cabling. • • • Maximum of 5 segments in a series. Inc. Maximum of 4 repeaters. Uses 10Base5 Thicknet 10Base5 Thicknet 10Base2 Thinnet Cable TV ARCnet Type RG-8 RG-11 RG-58 RG-59 RG-62 Impedance – Ohms 50 50 50 75 93 Specialized Solutions. In order for the network to operate at peak performance.
RG-62 Ethernet Cabling Cable Type Topology Max. Broadband transmission. Repeaters Max Segments with Nodes 3 10Base5 Coaxial Thicknet Coaxial Thinnet Bus 500 10 100 5 4 10Base2 Bus 185 10 30 5 4 3 268 Specialized Solutions.Network + Training & Test Preparation Guide Cable RG-58 /U RG-58 A/U RG-58 C/U RG-59 RG-6 Solid copper core. Length (meters) Speed Mbps Nodes Per Segment Max Segments Max. such as cable television. Military specification of RG-58 A/U. but also used for broadband transmissions. Larger in diameter and rated for higher frequencies than RG-59. . ArcNet networks. Description Stranded wire core. Inc.
Inc. Four twisted pairs with 4 twists per inch. but adds voice capability along with data. Not Defined Two 62. 3 4 5 6 7 8 9 . Four twisted pairs with three twists per inch. Contains a shield for use under carpets. Uses Voice ONLY 10 Mbps Data grade up to 16 Mbps. Specialized Solutions. Plenum grade. Same as type 1.5/125-micron multi-mode fibers. Cannot be used for 16 Mbps Token Ring. Four twisted pairs with 5 twists per inch. Two STP – 26 AWG wire. Voice-grade cable. Lower cost alternative to type 1 or 2. 269 Fiber Optic Data patch cables. IBM Cable Types (Token Ring) IBM has created its own standards for their Token Ring Networks. two STP and four UTP – maximum length 100 meters (328 feet). Not Defined Two STP – 26 AWG.Appendix A – Tech Summary UTP Cable Categories Category 1&2 3 4 5 Wire Specs Suitable only below 4 Mbps. Six twisted pairs. Type 1 2 Wire Specs Two STP solid core 22 AWG wires – maximum length 101 meters (331 feet). Two STP –26 AWG wire. Uses Connect between terminals and distribution boxes or between different wiring closets. Data grade up to 100 Mbps. Four UTP with two twists per inch – 22 or 24 AWG wire –maximum cable length is 45 meters (148 feet).
8 802.5 802.11 802.Network + Training & Test Preparation Guide IEEE 802. They also divide the Data Link Layer into two sub-layers: Logical Link Control and Media Access Controls. 802.x Standard 802.6 802.2 802.7 802.10 802.9 802.3 802.x Standards The IEEE 802 standards work in the Physical and Data Link layers of the OSI Model.1 802.12 Basis of Standard Internetworking Logical Link Control Sub Layer CSMA/CD Ethernet Token Bus LAN Token Ring LAN Metropolitan Area Networks (MAN) Broadband Technologies Fiber Optic Technologies Hybrid Voice/Data Networks Network Security Wireless Networks High Speed LANs 270 Specialized Solutions.4 802. . Inc.
The following is a standard configuration for IRQ settings: IRQ 0 1 2/9 3 4 5 6 7 8 10 11 12 13 14 15 Function System Timer Keyboard Controller Available COM2. COM3 LPT2 Floppy Controller LPT1 Real-time Clock Available SCSI/available Available Math Coprocessor Primary IDE Secondary IDE Available for Change No No Yes Usually Usually Usually-Often used for NICs.Appendix A – Tech Summary IRQ Assignments IRQ assignments can vary from computer to computer. 271 . Inc. however. No Usually No Yes Yes Yes If no math coprocessor No Usually Specialized Solutions. there are some that are always the same and some that can be changed. COM4 COM1.
LPT2 380 to 38F 390 to 39F 272 Specialized Solutions. . Inc.Network + Training & Test Preparation Guide In addition to IRQs you may have to set the Base I/O address. The following are common address assignments: 200 to 20F – Game Port 210 to 21F 220 to22F 230 to 23F – Bus Mouse 240 to 24F 260 to 26F 270 to 27F .LPT3 280 to 28F 290 to 29F 2A0 to 2AF 2B0 to 2BF 2C0 to 2CF 2D0 to 2DF 2E0 to 2EF – COM2 300 to 30F – Network Adapter Card 310 to 31F – Network Adapter Card 320 to 32F – Hard Disk Controller (For PS/2 Model 30) 330 to 33F 340 to 34F 350 to 35F 360 to 36F 370 to 37F .
Appendix A – Tech Summary 3A0 to 3AF 3B0 to 3BF – LPT1 3C0 to 3CF – EGA/VGA 3D0 to 3DF – CGA/MCGA (also EGA/VGA in color video Modes) 3E0 to 3EF 3F0 to 3FF – Floppy Disk Controller OSI Model Specialized Solutions. Inc. 273 .
x to 223.0 255.0 Number of Networks 126 16.255.0 255.Network + Training & Test Preparation Guide OSI Model and Connectivity Devices: Layer Number 7 6 5 4 3 2 1 Name Application Presentation Gateways Session Transport Network Data Link Physical Routers Brouter Bridges Switches NICs.x Default Subnet Mask 255.0.x to 191.x. Hubs.x.0.x 192.0.x.777.x.x 128.x.x. x.255.152 Number of Host 16. Inc.x.384 2.534 254 274 Specialized Solutions.097.x. . Repeaters Computers Devices Subnet Masking Subnet masks are used to divide an IP address into its network address and host address. x.x to 126.214 65. Subnet masks are assigned according to the following three classes: Class A B C IP Address 001.x.255.x.
1) to test the IP architecture and configuration.Appendix A – Tech Summary TCP/IP Ports A port is a virtual outlet that can be opened on a network device. the subnet mask.0. and default gateway. Uses a MAC address to find an IP address. Sends a test packet to a specified address. Use the loopback address (127. it will return. Here are some command-line utilities: IFCONFIG IPCONFIG Shows the Linux user's network interface configuration. the subnet address. Common ports are as follows: Service FTP TELNET SMTP HTTP POP3 Port 21 23 25 80 110 TCP/IP Utilities TCP/IP provides many tools for troubleshooting networks. 275 . If all is well.0. Displays the basic local host configuration – IP address. Inc. Used to see the entries in the Address Resolution table (uses IP addresses to find MAC addresses). PING ARP RARP Specialized Solutions.
In a star topology. 276 Specialized Solutions.) Used to verify entries on a DNS server. Use ROUTE PRINT to display contents. all computers are connected to a hub. Used to check the resolution of NetBIOS names to TCP/IP addresses. Used to verify the route to a remote host. all computers are connected in a series. Used to check the status of current IP connections. Inc.Network + Training & Test Preparation Guide ROUTE Used to see the local routing table and to add entries to it. (Pronounced Trace Route. NBSTAT NETSTAT TRACERT NSLOOKUP Topology Review In a bus topology. . ROUTE ADD to add entries and ROUTE DELETE to remove entries.
Specialized Solutions. all computers are logically connected in a circle. all computers are connected to each other. 277 .Appendix A – Tech Summary In a ring topology. In a mesh topology. Inc.
Inc. Used with TDR to locate cable breaks. and continuity of electronic devices and circuitry. TDR – checks and locates breaks in cables. resistance. . Can also be used for precise voltage measurements. Used to capture packets on a network and analyze them. An electronic device that graphically displays frequency and magnitude of analog signals.Network + Training & Test Preparation Guide Transmission Media Media UTP STP Coaxial Thicknet Coaxial Thinnet Fiber Optic Infrared Bandwidth (Mbps) 4-100 16-155 10 10 2000 1-10 Nodes/Segment 1 Varies 100 30 1 NA Maximum Nodes per Network 1024 260 300 90 1024 Varies Maximum Cable Length (meters) 100 100 500 185 2000 32 Troubleshooting Tools Hardware Volt/Ohm Meter Cable Tester Oscilloscope Uses Used to test voltages. Protocol Analyzer 278 Specialized Solutions. Also called a network analyzer.
Simple Network Management Protocol – used to monitor network devices (servers. Used to provide information for network baselines. and networks. 279 . interface cards. Event Viewer SNMP Specialized Solutions. servers. and bridges). Inc. routers. hubs.Appendix A – Tech Summary Software Performance Monitor Uses Use to monitor and graphically display various performance parameters found on workstations. Displays or prints a list of events.
Inc. .Network + Training & Test Preparation Guide 280 Specialized Solutions.
Appendix B – Useful Web Sites Appendix B – Useful Web Sites Microsoft: http://www.com Specialized Solutions.com Novell http://www.com Other Helpful Sites http://www.novell. Inc.microsoft. 281 .cnet.
Network + Training & Test Preparation Guide 282 Specialized Solutions. Inc. .
Appendix C – Network Standards Organizations Appendix C – Network Standards Organizations The networking industry is full of standards and committees making new standards. Perhaps the most famous standards are the "V" standards for modems and Faxes. For additional information. ANSI This is one of the most common standards in the computing industry. ANSI also is the United States representative on several international organizations like ISO and CCITT (see below). The American National Standards Institute (ANSI) is an organization of industry and business groups who develop trade and communication standards. it is responsible for establishing standards for communication. EIA The Electronics Industries Association (EIA) is a group of American manufacturers of electronic equipment. In the computing industry. let alone the networking industry. This appendix will summarize several of the important standards used in the network industry. CCITT The CCITT (Comité Consultatif Internationale de Télégraphie et Téléphonie) is an international organization also known as the International Telegraph and Telephone Consultative Committee. search for these organizations on the Internet. 283 . This is a common code for basic characters and numbers. Inc. As its name implies. Specialized Solutions. It is prominent in developing standards for the interface between data processing equipment and communication equipment. Perhaps the most well known standard is the RS-232 standard for serial communication via DB-9 and DB-25 connector. it is perhaps best known for the development of the ASCII character set.
x committee.x sub-committees. the data can be smoothly transferred.) publishes many standards for electrical and electronic equipment. Since they cover a wide variety of equipment. These standards are used for equipment operating in the Physical and Data link layers of the OSI Model. This is a common platform for transferring data from one database application to another. ISO The International Standards Organization (ISO) is responsible for establishing international standards for all services and manufactured product. 284 Specialized Solutions. the IEEE is subdivided into committees. . its emphasis is on SQL or the Structured Query Language. SAG SAG or SQL Access Group is working in conjunction with ISO to develop interoperability standards. A major ISO contribution to the network community was the development of the OSI (Open System Interconnection) model. The one that is important to networking professionals is called the IEEE 802. As you may guess from its name. As long as both are SQL compliant. Inc.Network + Training & Test Preparation Guide IEEE The IEEE (Institute of Electrical and Electronic Engineers. Inc. See Appendix A for a summary of the 802. Be careful to not get ISO and OSI confused.
Vouchers and coupons are also redeemed at this time. please have the following available: Social Security Number or Testing ID Two forms of ID (one with photo) Mailing address and telephone number. credit card or voucher. either by credit card. Method of payment. Individuals may retake the test as often as they like.2test. Prices subject to change without notice. go to www. To register via the Internet.vue. Date you wish to take the test. The test is available to anyone who wants to take the test. Inc. Specialized Solutions. or by requesting an invoice be sent to you or your employer.Appendix D – How to Register for the Exam Appendix D – How to Register for the Exam To Register for the Network+ Exams Register for the Network+ Certification Exam by calling 1-888-895-6116 for Prometric or 1-877-551-7587 for VUE.com for VUE.com for Prometric or www. Payment is made at the time of registration. When you call. and may be obtained by calling Prometric or VUE. Tests are given at both Prometric and VUE Authorized Testing Centers. Payment must be made each time you take the test. 285 .
Inc. .Network + Training & Test Preparation Guide 286 Specialized Solutions.
287 . The highest layer of the OSI Model. so they can communicate with other applications or nodes. program. or computers on the network (nodes). usually expressed in cycles per second (Hertz or Hz). Software. it supplies functions to applications. Attached Resource Computer Network Address Resolution Protocol The signal loss due to the physical properties of copper wire that happens over distance. American Wire Gauge AWG is the standard that describes wire thickness. The difference between the lowest and highest transmission channel frequencies. The file server on an AppleTalk network. Regenerates or amplifies a signal when it is passed through. The AWG wire number decreases as the wire thickness increases. or a circuit or device designed to handle such signals. Application Server ARCNet ARP Attenuation AWG Bandwidth Specialized Solutions. opposite of digital. Inc.Appendix E – Glossary Appendix E – Glossary Access Method ACK Active Hub Analog Signal AppleShare AppleTalk Application Application Layer A way of accessing the network. The Apple networking protocol. Acknowledgment message confirming receipt of the data packet. or bits per second (bps). A continuously variable signal. A dedicated server for applications. these three terms are often used interchangeably.
A LAN in which all workstations are connected to a single cable.Network + Training & Test Preparation Guide Base I/O Port Address Base Memory Address Baseband Beaconing BNC Connector BOOTP Boot Prom Bridge Broadband The channel through which data flows between a computer's hardware (such as a NIC) and the CPU. Inc. The signal flow is uni-directional. IP Address used by medium-sized networks. or DEC. . Companies contracted to carry our data over long distances. An area of memory that holds information for a peripheral device until it can be processed. The location in a computer's RAM of the beginning of the buffer area that is reserved for use by the NIC. British Naval Connector BOOTstrap Protocol Boot Programmable Read Only Memory is used on networks that utilize diskless workstations. Uses the entire capacity of the cable as a single channel. A bus driver. such as IBM. Broadband allows two or more channels to share the bandwidth of the cable or medium. such as Microsoft. Can also refer to a class of memory registers and devices that match data transfer speeds between computers and hardware (peripherals). these are all in use at the present time. IP Address used by very large networks. Class C IP addresses are used for smaller networks that do not exceed 254 hosts. Hardware that connects one network with another. A form of mobile computing. GM. A process used to identify any area on the network that may be experiencing problems. Buffer Bus Topology Carrier Cellular Networking Class A IP Address Class B IP Address Class C IP Address 288 Specialized Solutions.
surrounded by a tubular piece of plastic. using a specific protocol. Inc. A form of multitasking. Data that is encoded for security reasons. The method used by the NIC to count and pace the number of signals that it sends and receives. at the sender's level and then decoded at the recipient's level. stored. in which it is the responsibility of the currently running task to give up the processor. The signal bleed that occurs between individual wires in a cable. itself. from computer or network to another. is a number derived from. to allow other tasks to run. as recognized by a computer and transmitted across a variety media. Carrier Sense Multiple Access with Collision Avoidance Carrier Sense Multiple Access with Collision Detection Carrier Sense NetWare Changes the frame types between the LAN and WAN Information. An electrical cable consisting of a solid piece of metal wire surrounded by insulation. Same as a hub. Concentrator Cooperative Multitasking CRC Crosstalk CSMA/CA CSMA/CD CSNW CSU/DSU Data Data Encryption Specialized Solutions.Appendix E – Glossary Client Client Software Clocking Coaxial Cable User computer "being served" by another computer. Cyclic Redundancy Check. called a server. or Cyclic redundancy Code. Software used by the client. which is. or language. 289 . or transmitted with a group of data in order to detect data corruption.
) Being able to recover data from a disaster. which are large areas of data that are split into smaller non-contiguous blocks. When you type the IP address of the gateway routers you have installed on your network. The Data Link layer splits data into frames. Also called data striping. in a round-robin fashion. Domain Name System Default Gateway Demand Priority DHCP Digital Signal Disaster Recovery Disk Mirroring Disk Striping DMA (Direct Memory Access) DNS 290 Specialized Solutions. If the processor is capable of reading or writing data faster than a single disk can supply or accept it. Baseband uses digital signals over a single frequency. (Simple "on" or "off" signal.Network + Training & Test Preparation Guide Data Link Layer The Data Link layer is the second lowest layer in the OSI model.A method for leasing and maintaining that lease for IP addresses and related information to clients. It performs error checking and re-transmits frames that were not received correctly. It is the last stop before the data packets are placed on the media for transmission. . for sending on the Physical layer. so that one can take over for the other if it fails. DMA allows a device to read and write memory without intervention by the CPU. so that the segments can be written to multiple disk drives. It also receives acknowledgement frames. The use of two or more hard disks that "mirror" the main one. This access method is designed for the 100 Mbps Ethernet standard 100VG-AnyLAN Dynamic Host Configuration Protocol . the second disk can locate the next segment while data is being transferred from the first disk. Inc. this is the dividing into segments of logically sequential data. whichever one appears first on the list is considered the default gateway. A limited form of bus mastering. such as an individual file.
with a very large amount of storage space for shared files. File Allocation Table A server on a network that is configured to provide both incoming and outgoing fax services to the entire network. 291 DUN EISA Bus Ethernet EtherTalk Event Viewer FAT Fax Server Fiber-Optic Cable File Server Firewall Frame Relay Frames FTP Full-Duplex .25 packet switching technology. A set of programs running on a network's gateway server that monitors incoming and outgoing traffic and allows only authorized packets to be transmitted or received. Specialized Solutions. File Transfer Protocol Data can travel in both directions at once. A network's central computer. Dial-up Networking Extended Industry Standard Architecture is a PC bus that converts the PC bus from 16-bits to 32-bits. A local area network (LAN) recognized as the industry standard. Inc. An improved version of X.Appendix E – Glossary DSMN DSMN (Directory Service Manager for NetWare) is another add-on utility that is used to integrate user and group account information between the two operating systems. error detection. A Windows NT utility that will allow you to log any events and errors. Optical fibers carry digital signals in the form of modulated pulses of light. and other control information. A way to run AppleTalk on coaxial cable using an EtherTalk NB NIC. sent over a communications channel. A group of bits containing address information.
that enables two networks. and other information. Gateway Service for NetWare Half-Duplex can send transmissions both ways (send and receive). The portion of a packet that contains source and destination addresses. Internet Protocol This 32-bit host address defined by the Internet Protocol in STD 5. is an extension to the Internet Protocol (IP) that allows for the generation of error messages. to communicate with each other. It precedes the actual data. Text files that are used to look up and resolve names to IP addresses. GSNW Half-Duplex Header HOSTS and LMHOSTS files HTTP HTTPS Hub Hybrid Topology ICA ICMP ICS IFCONFIG IMAP4 Interoperability IP IP Address 292 Specialized Solutions. is usually represented in dotted decimal notation. Inc. defined in STD 5. Independent Computing Architecture Internet Control Message Protocol. RFC 792. or ring topologies. but only one at a time. HOSTS is used for DNS and LMHOSTS is used for WINS. RFC 791. using different protocols. star. test packets. and informational messages related to IP. . Hypertext Transfer Protocol HyperText Transport Protocol Secure The center of a cabling system or a network with star topology architecture. A network topology that combines bus.Network + Training & Test Preparation Guide Gateway A computer that acts as a translator. even though there may be multiple machines from multiple vendors. Internet Connection Sharing Shows the user's network interface configuration Internet Messaging Access Protocol The ability of software and hardware to communicate.
Multistation Access Unit in a Token Ring network. it's "hardware address. internally wired to connect the stations into a logical ring. 293 ISA Bus ISDN Kerberos L2TP LAN Laser Transmissions Latency LLC LocalTalk MAC Mail Server MAN Management Software MAU/MSAU ." Server used for E-mail. The MAC address is the address that is hardwired onto the NIC by the manufacturer. Specialized Solutions. A system for user authentication Layer 2 Tunneling Protocol Local Area Network A wireless network standard that uses laser beams for the transmission of data. Industry Standard Architecture refers to the bus architecture used in the IBM PC. and video data sources. across a network connection. Integrated Services Digital Network is a set of communication standards that allows a single wire or optical fiber to carry voice. A security protocol that works at network layer Interrupt Request causes the processor to temporarily suspend normal instruction execution and to start executing an interrupt handler routine. a device to attach multiple network stations in a star topology. The time it takes for a packet to go from sender to receiver.Appendix E – Glossary IPCONFIG IPsec IRQ DOS command that tells you the IP address for your computer. data. Logical Link Control – a sublayer of the Data Link Layer AppleTalk networks are usually called LocalTalk. Metropolitan Area Network The primary software package used by the administrator. Inc. Media Access Control – a sublayer of the Data Link Layer.
The transmitter and receiver are tuned to the same frequency. Network Attached Storage Network Address Translation NetBIOS Statistics NetWare Directory Services Names used with WINS. and is used by CompuServe. a 32-bit bus. Much like your local radio station. One of the most basic tools for electronic troubleshooting.400 and by ISO as Message-Oriented Text Interchange Standard (MOTIS). A method of data transmission. Single Frequency Radio.Network + Training & Test Preparation Guide MCA Bus Micro Channel Architecture. Tool used for testing the continuity and pin-outs of a cable Every device is connected to every other device by separate cables and has redundant paths. Inc. introduced by IBM for its PS/2 computer line. Media Media Tester Mesh Topology MHS Microwave Transmissions Multimeter Multistation Access Unit Multitasking Narrow-Band Radio NAS NAT NBTSTAT NDS NetBIOS Network Network Adapter Card 294 Specialized Solutions. The actual ring in a Token Ring network is in the hub. Message Handling System – A standard defined by ITU-T as X. totally incompatible with the original PC bus. A type of hub. Provides the physical connection to the network cable. A wireless network standard that uses microwave signals for data transmission. among others. MHS provides the functions for global E-mail transfer among local mail systems. . Performing multiple tasks simultaneously. protocol as well A group of computers linked together for the purpose of sharing resources. Also known as a network interface card.
Inc. A generic term used to describe a unit of data. A 32-bit architecture bus for PC expansion cards. Refers to the OSI (Open Systems Interface) Model. A Windows NT service that allows for interoperability with the NetWare NOS. A packet actually refers to Application layer data units (APDU). PCMCIA (Personal Computer Memory Card International Association) cards are credit card sized expansion buses that are used in portable computers (laptops) to provide the same expandability enjoyed by desktop computers. An adapter circuit board installed in a computer that provides a physical connection to a network. depending on the protocol. The hardware that is used to construct the network plays an important role at this layer. Network Operating System NT File System A TCP/IP utility command that will return information regarding the status of a network. Acts as a connection point only. A user has to enter a password to gain access to the network or to shared resources. including network connectivity. They extend the connection between the computer and the hub or between two hubs. A protocol that cannot be routed or passed through routers on a network. A "packet" may also refer to a frame or datagram. 295 Non-Routable Protocol NOS NTFS NTSTAT NWLink Octet OSI Packets Passive Hub Password Security Patch Cable PCI Bus PCMCIA Card .Appendix E – Glossary Network Administrator Network Interface Card (NIC) Network Layer The individual who has complete responsibility for maintaining a network. The network layer handles all the routing information as packets travel from one network to another. Specialized Solutions. Each part of an IP Address that contains eight bits of data is called an octet.
this feature has a different scheme called cooperative multitasking. Inc. Although included as part of Windows NT. The preemptive feature allows NT to hand out slices of CPU time. A hardware device.5 of Windows 3. Defines a channel between a device and the processor. Dedicated server for printing. which means that a process can take control of the CPU and check for other processes. many third-party applications are available. depending upon the needs of the user. The Presentation layer formats data exchange. used to circulate air through a building. converting character sets and encrypting data. A way of testing the server to see if it is alive and functioning. other processes will still run. This layer determines the interface hardware and the medium that will be used to transmit the data from the Data Link layer. . The Physical layer is the lowest layer in the OSI Model. A software tool that is used to monitor the performance of a network server. Post Office Protocol 3 Point-to-Point Protocol Point-to-Point Tunneling Protocol Introduced in version 3. Peripheral Physical Layer PING Plenum Port Number POP3 PPP PPTP Preemptive Multitasking Presentation Layer Print Server Protocol Stack 296 Specialized Solutions. allowing incompatible processes in the Application layer to communicate with the Session layer.1. and running on TCP/IP.Network + Training & Test Preparation Guide Peer-to-Peer Performance Monitor All the computers on the network can act as either a client or server. The space between the ceiling and the floor above. The OSI model is the ideal protocol stack. and even if a process takes full control. such as a printer or scanner. A group of protocols that are used to communicate between computers on a network.
which then routes the signal appropriately. Used to increase cable distances in network environments. the ring speed on the NIC is set to either 4 Mbps or 16 Mbps. to be accessed via a modem. Redirects a call from one port to another. For example. the devices are connected in a continuous loop. Used for "punching" down wire to a block Redundant Arrays of Independent Disks Uses a MAC address to find an IP address. Connector used with standard telephone wire. Inc. A service provided by Windows NT that allows most of the services provided by a network.e. Will hold up to 4 pairs of conductors. In Token-Ring networks. i. the proxy server. redirects a print job from the local port to the network printer. The signal is beamed towards a central unit. including support for dialup and logon. The services or peripherals that are shared over the network. For example. Connector used with UTP and STP network cables. Flat cable with 2 or 4 conductors. the user is connecting to the Internet via a secondary source. A protocol that can be routed over the internet or through routers on a network. In a Ring topology.Appendix E – Glossary Proxy Server One that serves many clients through only one connection. 297 . Storage Area Network Punch Down Tool RAID RARP RAS Redirector/Requester Reflective Infrared Repeater Resources Ring Speed Ring Topology RJ-11 Connector RJ-45 Connector Routable Protocol Router SAN Specialized Solutions. A device that forwards packets between networks.
SNMP is not limited to TCP/IP. Synchronous Digital Hierarchy The system used to protect data on a network from unauthorized use. Transmission rates are slower with this type. was developed to manage nodes on an IP network. ceilings. as opposed to duplex. usually over Ethernet.Network + Training & Test Preparation Guide Satellite Microwave Scatter Infrared A wireless network that utilizes microwave signals to transmit data. etc. Simple Network Management Protocol. data transfer. is software that allows the Internet Protocol (IP). defined in RFC 1055. until it reaches the receiver. to be used over a serial link. The effective distance of the signal is limited to about 100 feet. SDH Security Server Server Software Session Layer Sharing Shielded Twisted Pair Simplex Single-Frequency Radio SLIP SMAU SMTP SNMP 298 Specialized Solutions. A uni-directional data channel. RFC 1157. The Session layer handles such things as security authentication. acknowledgments (ACK). normally used on Ethernet. connection establishment and release. Software that resides on a server. as the signal is designed to bounce off of walls. A computer on a network that provides services to other computers. the Internet standard protocol defined in STD 15. . Narrow-Band Radio Transmission Serial Line Internet Protocol. Allowing files to be shared from one computer to another. A type of cable in which pairs of conductors are twisted together to prevent possible cross-talk from nearby wiring. Smart Multistation Access Unit Simple Mail Transfer Protocol is used to transfer E-mail between computers. Inc.
Maximum segment length is 500 meters. the official protocol of the Internet. or across large flat open areas. measured in Mbps (Megabits per minute). An access method used in a Token Ring topology. If the hub fails. Using binary addition.5 Standard) environment. Time-Domain Reflectometer – A cable tester. such as bodies of water or deserts. a router can determine what addresses are local and what addresses are for other subnets within the network. that uses a large diameter. A way to run AppleTalk in a Token Ring (IEEE 802. rigid coaxial cable with multiple shielding and an impedance of 50 ohms. This type of transmission is commonly used to connect multiple LAN segments together. A connector that has a built-in resistor in order to absorb signals and eliminate signal bounce. so it is less susceptible to eavesdropping. Specialized Solutions. A LAN topology that uses an access method called token passing. Secure Sockets Layer A LAN topology in which all workstations are wired directly to a central workstation called a hub. The process of subdividing a network into logical units. the entire network goes down. The maximum speed that "traffic" can move. Transmission Control Protocol over Internet Protocol.Appendix E – Glossary SONET Spread-Spectrum Radio Synchronous Optical Network Spread-spectrum broadcasts over a range of frequencies. 299 SSL Star Topology Subnet Mask Subnetting TCP/IP TDR Terminator Terrestrial Microwave Thicknet Thinnet Throughput Token Passing Token Ring TokenTalk . Inc. An Ethernet cable variant commonly known as 10base5. A form of microwave communication used for earthbased communication between two buildings. A type of coaxial cable whose maximum segment length is 185 meters.
Twisted network cables that do not have any shielding. Tool for stripping and cutting wire Tone Locator TRACERT Trailer Transceiver Transport Layer UDP UNIX Unshielded Twisted Pair Vampire Tap VLAN WAN WINIPCFG Wire Crimper 300 Specialized Solutions. RFC 768 is a connectionless protocol. The "hound. The Transport layer is responsible for packaging (and un-packaging) the data for transport. this applies a signal on the wires. When the receiver is placed in close proximity to the wire that has the signal applied. The "fox. A major operating system that is primarily used on minicomputers and has many features that are favored in the engineering and scientific environments.Network + Training & Test Preparation Guide Tone Generator Connected to the wires at the known location (the room with the outlet). Virtual LAN Wide Area Network A command used to display the current configuration of a Windows computer. User Datagram Protocol. defined in STD 6. A device that transmits and receives data. which. and for the errorfree delivery of the transmitted data." A receiver set to the frequency of the generator. Inc. it will emit a tone. thus locating the wires. The part of a data packet that contains the error corrections information. like TCP." Trace Route command in NT allows you to specify a remote host and report back on each subsequent router and the times it takes to traverse those routers in a command line interface. Additionally named traceroute in UNIX environments. Connectors that utilize sharp teeth to pierce the cable jacket to make the connection. . Used on transceivers. is layered on top of IP.
A named Subnetwork used for expanding the LocalTalk network or for relieving traffic on a larger network. 301 .Appendix E – Glossary WINS SERVER A way for Microsoft hosts to register themselves. Inc. AppleTalk can incorporate other types of networks. resolve and also release the mapping of their network NetBIOS name to an IP address. using zones Zones Specialized Solutions. such as Token Ring.
Network + Training & Test Preparation Guide 302 Specialized Solutions. . Inc.
7. Workstations need to be close together (in a relatively small area.Appendix F – Chapter Review Questions and Answers Appendix F – Chapter Review Questions and Answers The following are the questions found at the end of each chapter along with the correct answers. 303 . and peripheral devices. such as data. LANs typically also have much faster communication speed than WANs. 6. Simple to install. A WAN is created by connecting LANs together. data backups can be more easily and routinely performed. inexpensive to install (no need to buy expensive server). It is confined to a limited area. Access can be denied to unauthorized users (security). Specialized Solutions. What does MAN stand for and why is it no longer in use? Metropolitan Area Networks have been replaced by the Internet. What is the key difference between a local area network and a wide area network? A LAN is the basic building block (and smallest) of a network. 3. 4. Inc. No security. What is the main reason for networking computers? To share resources. configure. Review Questions Chapter 1 1. Name some disadvantages of a Peer-to-Peer network. What is a "sneaker net"? The "old fashioned" way computer users shared resources by taking a file on a floppy disk to the computer that had the services they needed to use. 5. A WAN is not geographically limited. Name some advantages of a Peer-to-Peer network. and manage (each user manages their own computer) for a small number of workstations (10 or less). Files are easily accessed by all users. applications. Name some advantages of having centralized documents. like one office). 2. Dragging a printer from computer to computer for users to utilize is another form of a sneaker net. loss of performance occurs if expanded over 10 workstations.
Centralized location of resources (server). Name two media access methods The access methods are CSMA/CD CSMA/CA. Can be expanded as network grows. Name some disadvantages of a Server-based network. Logical topologies represent the way that a networks functions. What is the difference between an operating system and a network operating system? Network operating systems are specialized operating systems designed to function in a network environment. More difficult to install and configure. What is the difference between a physical and logical topology? Physical topologies are the actual wires and hardware that we can see. Inc. The three basic topologies are: Bus. Ease of data backups. Non-preemptive multitasking is when the task decides when it is done with the CPU. Name some advantages of a Server-based network. Star. Review Questions Chapter 2 1. Expensive to install (will need to purchase expensive server). 304 Specialized Solutions. What is the difference between preemptive and non-preemptive multitasking? Multitasking means that a computer has the ability to perform more than one task at a time. 10. 11. and Demand Priority. 12. more difficult to manage (needs an administrator). Preemptive multitasking means that the operating system can take control of the processor without a task's permission. Token Passing. Centralized administration.Network + Training & Test Preparation Guide 8. They represent what the topology looks like. File and resource security available to limit unauthorized access. 9. . and Ring. Some NOSs function as the operating system that runs a computer's stand-alone functions as well as its network interfaces. Name the three basic topologies. 2. Increased performance on large networks.
web-publishing. The purpose of the redirector is to make network resources look like local resources to the application. 6. and file and print services. 8.Appendix F – Chapter Review Questions and Answers 3. redirecting them to the server. Inc. It is designed as an operating system that will overlay multi-operating system environments. 5. 550 MB of free hard drive space. What is NTFS? NTFS is the file system in Windows NT and it must be utilized in order to take full advantage of NT's security features. and volumes is also handled with NDS. management. servers. NetWare is a reliable operating system that provides excellent performance and security. It is a hierarchically organized database that provides security. Windows NT combines the _____________ and the ___________________ into one. routing. name service. NetWare is designed as an operating system that will overlay _____________ environments. messaging. 305 . 4. Organization of network resources such as users. Interoperability describes the ability of an operating system to interact with other operating systems. What is the purpose of the redirector? The redirector (in Novell NetWare it is called the requester) forwards requests away from the local bus. 7. Unlike NetWare. groups. 64 MB RAM. What is NDS? NDS (NetWare Directory Services) is the core of the NetWare operating system. 9. Specialized Solutions. What are the minimum hardware requirements for installing Novell NetWare version 5? Pentium Class or Higher CPU. Windows NT combines the operating system and the network operating system into one. Define interoperability.
2. 12. Review Questions Chapter 3 1.What type of network would utilize Windows for Workgroups as an operating system? Windows for Workgroups is a version of Windows 3. NWLink is a protocol based on Novell's IPX/SPX and is used for communication between the two systems. GSNW (Gateway Services for NetWare) provides the gateway between an NT domain and the NetWare server. What type of computer was developed by Apple computer in 1984? The Macintosh 15. Data Link. and Physical 3. . Application. CSNW (Client Services for NetWare) allows NT workstations to use file and print services on a NetWare server. What is a domain? NT uses domains in order to accomplish its security goals. Session. 16 MB RAM. 11. FPNW (File and Print Services for NetWare) allows NetWare clients to access NT file and print services. Who developed the OSI model? The OSI model was developed by ISO (International Organization for Standardization). 13. A domain is simply a group of workstations with a shared security database. 125 MB free hard drive space. Name some of the services and protocols that Microsoft included with Windows NT to ensure interoperability with NetWare. Presentation. What OS is similar to UNIX and is a publicly open system? Linux 14. What are the minimum hardware requirements for Windows NT Server? 476DX-3 CPU. Name the seven layers of the OSI model.1 that includes the ability to run a peer-to-peer network. A network adapter card operates at the _______ layer of the OSI model Network layer 306 Specialized Solutions. Migration Tool for NetWare is used to convert NetWare accounts to NT.Network + Training & Test Preparation Guide 10. DSMN (Directory Service Manager for NetWare) is used to integrate user and group account information between NT and NetWare. Transport. Network. Inc.
It is a computer's physical address. Which OSI layer is responsible the MAC address? The Data Link layer 8. It translates data into a format that is compatible with the network and back into a format that is compatible with the computer. Which part of this MAC address is the Device ID? D3-B4-01 14. Physical 10. What is the function of the Presentation Layer? The Presentation layer is the translator for the network. managing. A bridge operates at the ________ layer of the OSI model. This is not the actual application or program.Appendix F – Chapter Review Questions and Answers 4. Network Layer 6. Which OSI layer is responsible for establishing. Presentation layer 7. Inc. 9. 307 . 13. Which OSI layer makes routing decisions? The Network layer Specialized Solutions. What is a MAC address? The MAC address is another name for the 12-digit (6-byte) hexadecimal address that is hardwired on the NIC by the manufacturer. and ending connections? The Session layer 12. Data Link layer 5. 11. A router operates at the _________layer of the OSI model. Data compression takes place at the __________ layer of the OSI. What is the function of the Application Layer? The Application layer is responsible for communication between a user's application and the network. The ____________ layer is responsible for the mechanical and electrical functions of transmitting data over a network. simply a support layer that allows an application to use the network by acting as a translator.
Network + Training & Test Preparation Guide 15. Which OSI layer is responsible for delivering data in sequence, without duplication and error free? The Transport layer 16. The Data Link layer has been split into two sub-layers. What are they? The Logical Link (LLC) layer and the Media Access Control (MAC) layer 17. What is the function of a Gateway? A gateway translates between two networks that use different protocols. A computer with special software serves as a gateway and allows for communication between completely dissimilar networks. 18. Which IEEE standard defines the Logical Link Control (LLC) sub-layer? 802.2 19. What are NDIS and ODI? They are Network Adapter Card interface specifications. They are incompatible with each other. NDIS (Network Driver Interface Specification) was co-developed by Microsoft and 3Com, while ODI (Open Data Link Interface) was co-developed by Novell and Apple. The purpose of these standards is to allow operating system vendors to write multiple drivers for the same NIC. This way more than one protocol can be bound to a single NIC. 20. Describe protocol binding. In order to function, a protocol must be bound to the NIC. This binding process is what links the protocol stacks to the NIC driver. It is possible to bind two protocols the one NIC (such as TCP/IP and IPX/IPX) or to have two NICs with one protocol bound to each one. The order in which these protocols are bound to the NIC determines which one the network operating system will attempt to use first. 21. Which is faster, connection-oriented communication or connectionless communication? Connectionless communication is faster, but connection-oriented communication is more reliable. 22. . Name as many routable protocols as you can remember. AppleTalk, DECnet, IPX/SPX, PPP, PPTP, SLIP, SMB, SNA, TCP/IP, UDP, X.25, XNS 23.. You have expanded your NetBEUI network into two segments and are using an intelligent router to optimize network traffic. Will this work? Why or Why not? 308
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Appendix F – Chapter Review Questions and Answers No, NetBEUI is a non-routable protocol.
Review Questions Chapter 4
1. What is the maximum segment length of Thinnet? 185 meters 2. What is the maximum segment length of Thicknet? 500 meters 3. What type of connectors are used with Coaxial cable? BNC connectors 4. What is the purpose of a transceiver? A transceiver is a device that both transmits and receives data on a network. 5. How is a vampire tap connected? They utilize sharp teeth that puncture the cable to make the connection. 6. What is the purpose of plenum cabling? Plenum grade cabling is used in the plenum (the space between the ceiling and the floor above, which is used to circulate air in a building). Fire codes usually call for special cable in this area because PVC cable gives off poisonous gas and fumes when burned, which would end up being circulated throughout the building. 7. What is the maximum segment length of UTP? 100 meters 8. What is the transmission speed of category 5 cabling? Up to 100 Mbps
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Network + Training & Test Preparation Guide 9. What is the most popular of the cable types? UTP is the less expensive of the twisted pair cable types. It is also flexible and easy to install, making it the most popular cable type. 10. Which twisted pair cabling is less sensitive to EMI? STP is insulated with a foil mesh between the wire pairs, which results in less sensitivity to EMI and crosstalk. 11. What type of connector is used with twisted pair cable? RJ-45 connectors 12. What is the most expensive cable type? Fiber-Optic cable is the ideal cable type for networking. However, it is the most expensive and most difficult to install. 13. What is the least expensive of the cable types? UTP is the least expensive of the cable types. It is also flexible and easy to install, making it the most popular cable type. 14. List some advantages of fiber-optic cable. Fiber-optic supports extremely high bandwidths, segment lengths of up to several miles, and it is not subject to EMI or eavesdropping. 15. What does AWG stand for and what is it? American Wire Gauge (AWG) is the standard that describes wire thickness. The AWG wire number decreases as the wire thickness increases. 16. Describe baseband. Baseband uses the entire capacity of the cable as a single channel. 17. Describe broadband. Broadband allows two or more channels to share the bandwidth of the cable, making the signal flow unidirectional. 18. What is the difference between simplex, half-duplex, and full-duplex communication? Simplex communication is one way, can receive but not send. For example, a pager. Half-duplex communication can send or receive, but not at the same time. For example, a CB radio. Full-duplex can send and receive signals at the same time. For example, the telephone. 310 Specialized Solutions, Inc.
Appendix F – Chapter Review Questions and Answers 19. What is the function of a network adapter card? Network Adapter Cards or Network Interface Cards (NICs) are used to connect the computer to the network. (They make the physical connection to the network.) NICs translate the data that computers can understand into signals that can be transmitted over the network medium and back again. 20. In Token Ring networks, what are the two ring speeds available? In a Token Ring network if the correct ring speed is not selected a computer will not be able to connect to the network. The two choices available are 4 Mbps and 16 Mbps. 21. Where would you expect to find a PCMCIA card? PCMCIA (Personal Computer Memory Card International Association) cards are credit card sized expansion buses that are used in portable computers (laptops) to provide the same expandability enjoyed by desktop computers, including network connectivity. 22. What are some of the reasons you would need to install a wireless network? To create a temporary network, to backup a cable-based network, to provide a mobile network environment, for areas where running cable would be impossible or unsightly, outdoor installations and to connect to remote sites such as a ship or oil platform. 23. What are the four basic wireless transmission types? Infrared, Laser, Radio, and Microwave 24. Which is the most secure type of radio wireless network? Spread-Spectrum Radio is more secure than Single-Frequency Radio (Narrow-Band Radio) because it broadcasts over a range of frequencies instead of just one. 25. Which microwave transmission type is used to transmit globally? Satellite microwave is used to transmit globally; Terrestrial microwave is used to transmit over shorter distances.
Review Questions Chapter 5
1. What are the three primary access methods? CSMA/CD & CSMA/CA, Token Passing, and Demand Priority Specialized Solutions, Inc. 311
Network + Training & Test Preparation Guide 2. Describe the difference between the two different contention methods CSMA/CD and CSMA/CA. CSMA/CD stands for Carrier Sense Multiple Access with Collision Detection and CSMA/CA stands for Carrier Sense Multiple Access with Collision Avoidance. Both CSMA/CD and CSMA/CA listen to the network cable to determine if it is free (Carrier Sense), if no data is traveling, a CSMA/CD computer will transmit. If there is another computer on the network that transmitted at exactly the same time, a data collision will occur, and both sets of data will be destroyed. CSMA/CD detects that a collision has occurred and waits a specified amount of time before re-transmitting. With CSMA/CA the process is much the same except that instead of just transmitting when it senses that the cable is free, it will send a signal that it is about to transmit. This will cause any other computer that was about to transmit to wait and so data collisions are avoided. This extra step can slow down network traffic, so CSMA/CA is not the most popular of the two contention methods. 3. Why isn't token passing considered a contention method? A computer on a token passing access method network must possess the token in order to transmit data. Therefore, only one computer at a time will transmit in this kind of architecture, and so, no contention. 4. Describe how data is transmitted in Token Ring architecture A token, which is a special kind of packet, is circulated around the ring from computer to computer in a Token Ring network. A computer that wants to send data onto the network waits until the token is passed to it and takes possession of it. The transmitting computer encodes the token with the data that it wants to transmit, as well as header and trailer information that contain the destination and source addresses, as well as error control information. It then passes the token back out onto the ring where it travels on until it reaches the destination computer. The destination computer copies the data into its buffer and adds some acknowledgment information (or re-transmittal information if it detected errors) and releases the frame back out onto the network where it travels back to the source computer. Assuming that the data was transmitted error-free, the source computer removes the "used" frame from the network and creates a new "free" token to release back out onto the network.
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Appendix F – Chapter Review Questions and Answers 5. What happens if two computers using the demand priority access method transmit at exactly the same time? If the hub receives two transmissions at exactly the same time the one with the highest priority is processed first. If the two transmissions have the same priority level, they are processed at the same time by alternating between the transmissions. 6. How is data transmitted over the network cable? In packets or frames. (Small chunks of data at a time.) 7. What is CRC and what part of the packet is it usually located in? CRC (Cyclical Redundancy Check) is a mathematical calculation that is calculated at the source computer and included in the trailer of the packet. When data arrives at the destination computer, the calculation is redone and if it calculates as it did at the source computer it is assumed that the data arrived intact. 8. What sort of information do packet headers contain? The header contains information such as an alert signal that announces that data is being transmitted, the source and destination addresses and clocking information. 9. What does the "T" in 10BaseT indicate? The first part indicates transmission speed (10 means it transmits at 10 Mbps), the second part "Base" indicates that it uses baseband (single channel) technology and the last part indicates the cabling type, or maximum segment length in the case of coaxial cable. ("T" indicates Twisted-pair). 10. What is the maximum segment length in 10Base2? 185 Meters. The "2" in this case means 2 times 100 meters, but in the case of Thinnet coaxial cable the maximum segment length is 185 meters. 11. What type of connectors are used in 10Base5? BNC connectors 12. What type of cable is used in 10BaseFL? Fiber-Optic 13. Name the two main 100 Mbps Ethernet Standards. 100VG-AnyLAN, also called 100BaseVG, VG, and AnyLAN. The VG stands for Voice Grade. 100BaseX is sometimes called Fast Ethernet. It has different specifications depending upon the type of cabling used (hence the "X" in the area that indicates cable type). Specialized Solutions, Inc. 313
5 standard 16. This is a hub that has all of the features of an active hub (regenerates or amplifies the signal) with additional capabilities such as certain network management functions. Describe a MIC connector. Since no other computer can transmit while one computer has the token. Describe beaconing as it applies to Token Ring architecture. It does this by transmitting a signal every seven seconds. What are the two transmission speeds of Token Ring? 4 Mbps and 16 Mbps 17. The active monitor (which is the first computer to go online) is responsible for monitoring network activity to make sure that frames are being sent and received accurately.3 standard 15. What is a SMAU? SMAU stands for Smart Multistation Access Unit. This signal is called beaconing and it travels from computer to computer. 314 Specialized Solutions. It is more commonly set up to travel clockwise. .Network + Training & Test Preparation Guide 14. A SMAU may have the capability to shut down a connection that is producing errors thereby allowing the rest of the network to function. MIC (Media Interface Connectors) are connectors that have neither male nor female ends. 19. 18. If a computer doesn't receive an expected signal from its upstream neighbor it will notify the monitor that a problem may exist. How are data collisions avoided in the Token Ring architecture? A computer must posses the token in order to transmit data. Which IEEE Specification defines Ethernet? The IEEE 802. Inc. The main thing is that data only travels in one direction on a Token Ring network. It also ensures that only one token is traveling the ring at a time and investigates any frames that have traveled around the ring more than once. Which IEEE Specification defines Token Ring? The IEEE 802. while IBM says that it travels counter-clockwise. data collisions are avoided. It can be either depending upon how it is set up. however. 21. Which way does data travel in a Token Ring network? Which way data travels in a Token Ring network is a matter of convention. 20. IEEE 802. Any connector can be connected to another MIC connector.5 says it travels clockwise. They are also called hermaphrodite connectors.
it stores it to use each time it connects to the network. Specialized Solutions. 3. etc. If no other computer is using the address. It first goes to computer #1 and then #2. What are the two areas of concern when starting a network project? You will need to consider the customer and the network goals. How does data flow in an ARCNet network? The token is passed around the network in numerical order. It then broadcasts the address to determine if any other computer on the network is using it. What is the number one reason for choosing a client/server network? The number one reason for using a client/server network is security. Is NetBEUI a good protocol to use with a large WAN? No. 23. 5. It also provides a print server. What are the two tools required to initiate a network design? All you need to start a network project is a pencil and some paper. 315 .Appendix F – Chapter Review Questions and Answers 22. It does this even if computer #1 is at the opposite end of the network from computer #2. 2. What is the purpose of AppleShare? AppleShare is the name of the file server on an AppleTalk network. How does a computer on a LocalTalk network obtain its address? When a computer first comes online in a LocalTalk network it randomly selects an address from a range of allowable addresses. What are the two most prominent reasons to choose a peer-to-peer network? The best reasons for using peer-to-peer are its simplicity and low cost. 25. 24. Inc. NetBEUI is a non-routable protocol and will not interface with routers. What type of access method is utilized by an ARCNet network? Token-passing. Review Questions Chapter 6 1. 4.
Your accounting office found a really good deal on network cards. he intends to expand the network in the future. Review Questions Chapter 7 1. Passive hubs are used only to make connections.com/windows/catalog.Network + Training & Test Preparation Guide 6. What is the difference between an active hub and a passive hub? Active hubs are used to connect nodes and boost the signal strengths. Also. 7. but not enough to run it efficiently. What is the difference between a hub and a MAU? Hubs are used with Ethernet networks and MAUs are used with Token Ring networks. 9. Your company just bought ten new computers and all are guaranteed to meet the minimum requirements of Windows XP. Inc. An active hub requires some input power. 2. You are expanding your network and will need to invest in 50 to 100 new network cards. 8. It will be less costly to install CAT 6 now than to replace the CAT 5 later when the network needs to be upgraded from 100 Mbps to 1 Gbps to handle the higher traffic. Why should you refuse this offer? First.microsoft. Give one reason why you should recommend that he spend a little more now and install CAT 6 cabling instead of CAT 5. How do you know if a new piece of hardware will work with Windows XP? Check the Windows Catalog on the web at www. However. Your client is installing a small Ethernet network and trying to save money at the same time. having to maintain a variety of network cards will increase the workload of your IS department – it is better to standardize network cards in a large network. . you cannot be sure that they will meet the specifications of your network. 316 Specialized Solutions. but they are not all the same. Was this a good purchase? No – the minimum requirements are just enough to run the NOS.
Bridges work in the Data Link layer of the OSI model. What is analog communication? Analog communication is based on PSTN or public switched telephone network. Router . a router. NetBEUI is not routable. Security host. A bps or bit per second is the actual data transmission rate of a modem. but it can switch packets across multiple networks. BAUD rate is the number in cycles per second of the carrier signal of a modem. A bridge can be used to isolate segments on a LAN. ISDN.A bridge does the same things as a repeater but has one additional feature. Callback Security. 4. Describe the difference between BAUD and bps. 317 .Gateways make it possible to connect different network architectures. Gateway . 5.A repeater is a device that is used to extend the cable lengths of a network segment. Frame Relay.Appendix F – Chapter Review Questions and Answers 3. BAUD and bps were the same thing. In older modems. SLIP. 8. Name three advanced WAN environments.A router has all the features of a bridge. They do not translate or filter any information. What are the two components of remote network accessing? RAS (remote access server) and DUN (dial up networking). thus reducing the traffic for each segment. and SONET 7. Bridge . Specialized Solutions. Name four forms of RAS security. BAUD is limited to 2400 bps.544 Mbps transmissions is called? T1 6. A form of digital line that is capable of 1. They do however. 10. PPTP and L2TP 9. PPP. amplify the signal thereby compensating for signal loss due to long cables. Define a repeater. a bridge. Think of a gateway as a computer that acts as a translator between two networks that don't speak the same language. Auditing. For example. Repeaters work in the Physical layer of the OSI model. Not all network protocols will work with a router. and PPTP filtering. They can also determine the best path for "routing" traffic and filter broadcast traffic to the local segment. and a gateway. Inc. Repeater . Name three RAS protocols.
Who is responsible for maintaining top-level domains? The InterNIC (Internet Network Information Center) is responsible for top-level domain names. Name three of the five other protocols used within TCP/IP Additional protocols are: POP3. and ARP. UDP. Which of the name resolution services will work only in Windows? WINS 9. ICMP.Network + Training & Test Preparation Guide Review Questions Chapter 8 1. Internet and Network Interface. 7. FTP. Transport. IPv4 addresses consist of a ______ bit number. 3. SMTP. What is a domain? A domain is a group of computers that share a common general purpose. SNMP. 5. IP. HTU UTH 6. How many primary protocols are used to make the TCP/IP Suite? There are five primary protocols: they are – TCP. 32 10. What is the purpose of DNS? The Domain Name System is used to resolve host names into IP addresses. 4. Inc. 2. What is an FQDN and give an example? FQDN is a Fully Qualified Domain Name. What is the value of the leading bit (one on the far left) for a Class A IP address? Class B? Class C? Class A Class B Class C 318 01-126 128-191 192-223 (leading bit is 0) (leading bit is 1) (leading bits 11) Specialized Solutions.com. An example is http://www. . What are the four layers that make up the TCP/IP protocol suite? The four layers of TCP/IP are: Application.microsoft. and HTTP. 8.
Appendix F – Chapter Review Questions and Answers 11. Inc. Event Viewer. Specialized Solutions. List as many as you can. U U U U 12. SNMP (Simple Network Management Protocol) 3. 2. ROUTE. TCP/IP provides several tools that you can use to validate the statistics of your network. 319 . NETSTAT and TRACERT. You are the manager of a large network and have been getting complaints about the system being slow. What kind of software package can you purchase to help analyze your network? Network Management Software is used to analyze network traffic and network status. What are five reasons to use subnetting? Connect physically remote local networks Connect a mix of network technologies (Ethernet and Token Ring) Allow an unlimited number of hosts to communicate Reduce network traffic by limiting broadcast and local traffic to a single segment Review Questions Chapter 9 1. In order for your new network management software to monitor the activities of the entire network. Subnetting is the process of breaking an IP address into _________ and ________ groups Subnetting is the process of breaking an IP address into meaningful and manageable groups. NBTSTAT. each device will need to be _________ compliant.
4. What purpose does encryption play in your security model? Encryption encodes a message so that it cannot be read if it is intercepted during transmission. 2. It can also be configured to prevent unauthorized transmissions from leaving your network.Network + Training & Test Preparation Guide Review Questions Chapter 10 1. 320 Specialized Solutions. Resources 3. What are the three most common levels of RAID? RAID 0 Non-redundant striped array RAID 1 Mirrored arrays RAID 5 Striped array with parity 6. . 5. Inc. passwords are assigned to __________. In a share level model. What are the two requirements of user level logon? The user must type in a Username and a Password. The acronym RAID stands for____________? Redundant Array of Independent Disks or Redundant Array of Inexpensive Disks. What is the function of a firewall? A firewall is used to prevent unauthorized access to your network from outside via the Internet.
you should see the green light that indicates that the network card has detected the presence of a network. 8.Appendix F – Chapter Review Questions and Answers Review Questions Chapter 11 1. What TCP/IP utility can you use to find the IP address of the workstation? You can use IPCONFIG from a DOS prompt or if using Windows. Inc.0. 6. but need to know which of the 50 cables goes to the accounting office. You are troubleshooting a cable problem.1 7. The fox and hound. What is the loopback IP address? 127. and think it might be shorted. are you finished with the troubleshooting process? NO – You still need to confirm the repair and document the problem and solution. Isolate the Problem. 2. What is the easiest way to tell if the network card can "see" the network? If the network card has indicator lights. 3. You need to know the IP address of a workstation. After repairing a problem. You have found the cabinet with the patch panel and hub. You have located the cable in question #3. What would be the best tool to help you locate the cable in question? The best tool for isolating a single cable from many is the tone generator or tone locator. You are working with a TCP/IP network and want to confirm the protocol stack in a specific workstation.0. What utility can you use to confirm the protocol stack is good? PING the loopback IP. 5. What are the three primary steps to take when troubleshooting? The three steps to troubleshooting are: Define the Problem. 4. Specialized Solutions. What tool would you need to find the short? TDRs (Time-Domain Reflectometers) are used to locate shorts in cables. You have just connected a workstation to the network. and Repair the Problem. WINIPCFG from the RUN command. 321 .
10. . You have a Windows 2000 network and received complaints that the server is running slow.Network + Training & Test Preparation Guide 9. Inc. What is the difference between bandwidth and throughput? Bandwidth is the amount of traffic that a network can handle at a given time. Throughput is the maximum speed that a message can be transmitted. What utility can you use to determine the performance of the server? Performance Monitor 322 Specialized Solutions.
226 Bandwidth. 52 Data Protection. 81 Category 5. 70 DMA. 79 backup utility. 161 Cyclical Redundancy Check (CRC). 81 Cellular Networking. 196 client software. 24 Address Resolution Protocol. 114 10BaseFL. 109 DES (Data Encryption Standard). 230 Differential backup. 16. 67. 34 DECnet. 13 ARCNet. 164 Class A. 69. 92 Boot Sector. 42 base memory address. 50 application server. 78. 21 Carriers. 243 CSMA/CD. 114 A access method. 166 attenuation. 13 Clocking. 77 Computer compatibility. 196 Class C. 108.Appendix F – Chapter Review Questions and Answers Index 1 100BaseX. 34 clients. 78. 61 C Carrier Sense Multiple Access with Collision Detection (CSMA/CD. 119 binding. 38 Client Software. 196 Class B. 79 AWG. 41 CSU/DSU. 109 CSNW. 226 Digital. 111 D Data Link Layer. 67 demand priority. 186 Analog. 151 connection-oriented. 123 ARP. 65 BNC. 65 continuity. 42 active hubs. 189 domain controller. 60 Broadband. 78 Boot Prom's. 40. 231 BOOTP. 86 B backbone. 39 Circuit-switched. 86 Beaconing. 116 10Base2. 91 domain. 323 . 217 ATM. 114 10BaseT. 108 Active Directory. 121 Application Layer. 89 cloud. 91 Baseband. 70 coaxial cable. 98 Change. 90 DLC. 253 Banyan VINES. 122 AppleTalk. 39 AUI connector. 114 10Base5. 191 BRI. 116 100VG-AnyLAN. 86 Broadband Optical Telepoint. 96 brouter. 60 attributes. 89 AppleShare. 167 bridge. 89 Direct Memory Access (DMA). 160 Category 3. Inc. 40 Specialized Solutions.
197 IPX. 21. 226 FDDI . 60 E EES. 68. 161 . 144 Ethernet. 249 IPsec. 167 ISDN adapters. 56 324 Specialized Solutions. 226 Infrared.Fiber Distributed Data. 159 Gigabit Ethernet. 41 Frame Relay. 166 fiber-optic. 122 Event Viewer. 224 FPNW. 191 dynamic routers. 194 IPCONFIG. 70 Layer Two Tunneling Protocol. 96 LAT. 22 FAT. 185 IP address. 245 DSMN. Inc. 83 File Infectors. 157 hybrid topologies. 167 FTP. 217. 83 IBM Type 3 UTP. 185 interoperability. 116 ground probe. 186 Internet Protocol (IP).Network + Training & Test Preparation Guide Domain Name Service (DNS). 41 Dynamic Host Control Protocol (DHCP). 231 EISA. 91 IBM cabling. 81 environment. 174 LAN. 68. (IEEE). 39 IP. 67 IRQ. 86 firewall. 41 H Half-Duplex. 114 EtherTalk. 174 L L2TP. 191 gateways. 231 fire codes. 18 I I/O port number. K Kerberos. 62 Internet Control Message Protocol. 93 ISDN. 226 Full Control. 217 IMAP4. 71 ICS. 174 IPv6. 39 Full-Duplex. 39 fault tolerance. 191 HTTP. 91 ISA. 187 Full backup. 192 IFCONFIG. 120 ICA. 86 headers. 12 Laser. 186 Incremental backup. 174 Line-of-Sight Infrared. 86 G gateway. 96 Linux. 174 ICMP. 243 Group policies. 215 F Fast Ethernet. 61 Gateways. 93 EMI. 42 GSNW.. 42 Headers. 189 Domain Reflectometer (TDR). 96 Institute for Electrical and Electronic Engineers. 187 hubs. 187 HTTPS. 112 HOSTS file. Inc.
Primary Domain Controller. 243 multitasking. 190 NETSTAT. 23 Passwords. 69 NLSP. 232 Managing User Accounts. 217 NTFS. 23 media access methods. 52 Network Neighborhood. 157 MAUs .Appendix F – Chapter Review Questions and Answers LLC. 18 LSL. 67 M Macintosh. 120 Multimeter. 68 O ODI.Multiple Access Units. 168 MSAU. 120. 151 Media Tester. 13 peer-to-peer. 215 NCP. 89 passive hub. 29 OS/2. 37 MIB (Management Information Base). 98 packets. 89 Network Layer. 49. 71. 122 logical topology. . 229 Patch Panel. 67 modem. 36 NetBEUI. Inc. 36 NetWare Client32 for Macintosh. 70 NETBIOS. 37 Network Adapter Cards. 243 mesh topology. 96 MLID. 64 NDS (NetWare Directory Services). 217 PING. 29 NSLOOKUP. 86 PPP. 215 NetWare. 64 Open Systems Interface (OSI). 93 PCMCIA. 157 PCI. 32 P Packet switching. 21 Media Compatibility. 14 Peer-to-peer LANs. 249 plenum. 49 operating system. 107 protocols. 69 Network-attached storage (NAS). 34 MAU. 18 Ping. 192 Punch Down Tool. 67 NDIS. 111 parallel communication. 114 LMHOSTS. 71. 30 N NAT. 36 NetWare Client32 for Windows 95. 164 Packet-Radio Networking. 36 NetWare file server. 36 NetWare Client32 for DOS. 39 Null-Modem. 172 PPTP. 18 MHS. 242 325 Specialized Solutions. 37 NetWare security. 43 Macro Virus. 93 PDC . 231 physical topologies. 114 Network Time Protocol (NTP). 67 No Access. 41. 31 Network standards. 31 PGP. 36 NetWare Client32 for OS/2. 171 NWLink. 37 NetWare Print Services. 228 NFS. 30 PRI. 167 protocol. 213 MIC (Media Interface Connectors). 191 NBTSTAT. 39 NOS – Network Operating System. 120 Microwave. 64 proxy server. 172 Preemptive multitasking. 191 LocalTalk.
71. 175 Security. 199 T tape backup. 16 TRACERT. 182 UNIX. 144 Remote Access Server or RAS. sneaker net. 174 Standards.Network + Training & Test Preparation Guide R Radio. 51 Trivial File Transfer Protocol (TFTP). Inc. 159 routers. 39 redirector. 118 topology. 60 Storage Area Network (SAN). 77 Thinnet. 69 ROUTE. 60. 225 TCP. 230 S SAP. 79 Transport Layer. 34 server-based network. 17 static routers. 187 Software analyzers. 79 Simple Network Management Protocol (SNMP). 221 segment. 253 TLS. 215. 68. 96 RAID. 17 RIP. 245 SONET. 13 Server-based network. 21. 16. 172 SMAU. 227 RARP. 71. 109 token ring. 158 requester. 69 terminator. 96 relative humidity. 68 Satellite Station Networking. 144 Server Software. 33 servers. 217 Read. 58 . 69. 77 throughput. 112 transceiver. 68 SMDS. 215 router. 13 sharing applications. 167 SPX. 96 SDH. 213 Simplex. 89 Server room. 68. 65 RPC. 71 RSA. 80 virtual connections. 237 trunk. 35 ring topology. 232 troubleshooting. 34. 184 Telnet. 171 removable disks. 174 token passing. 35 Reflective Infrared. 120 SMB. 86 SLIP. 11 SNMP. 16. 16 serial communication. 249 Trailer. 167 security. 67 SSL. 225 removable optical disk. 167 SMTP. 187 SNA. 152 star topology. 16 twisted-pair. 68 Trojan Horses. 68 326 Specialized Solutions. 79 thicknet. 80 V vampire taps. 80 U UDP. 60. 81 Subnetting. 98 Scatter Infrared. 11 signal bounce. 185 UTP. 67. 42 User Datagram Protocol (UDP). 225 repeater. 228 STP.
69. 31 Windows for Workgroups. 190 Wire Crimper. 40 U U WINS. 32 Windows 2000. 92 workstation. 165 VPN's (Virtual Private Networks). 19. 231 VLAN. Inc. 71 XNS. 166 XDR. 31 Windows NT Print Servers. 12 Warp Connect.25. 95 Wireless NICs. 124 wireless network. 154 Windows 95/98. 230 W WAN. 13 X X. 70 Specialized Solutions. 327 .Appendix F – Chapter Review Questions and Answers Viruses. 242 Wireless.
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