72 in-band, 272 common problems, 84-87 LOS (loss of signal), 285 duplex mismatch, 85 out-of-band, 273 unidirectional links, 86 T1 AMI signaling, 270 corporate network design, 477 simplifying properly sized production designing to prevent problems, 87 network, 525 MAC address table instability in looped single rack unit (1-RU) models (multilayer environment, 72 switches), 203 managing, 77-80 SLB (server load balancing), 395-404 PortFast feature, 80 alternative types of load preventing loops with, 73-76 balancing, 396-398 routing protocols vs., 93 configuring, 399-404 switch ports used to connect PIX CSMs, 401-404 firewalls, 379 IOS SLB, 399-401 UplinkFast feature, 81 how it works, 398 Spanning Tree Protocol (STP), 66, 233 slots in 6509 switches, 209 spanning-tree backbonefast command small networks, 482 (IOS), 84 smart jack, 266 spanning-tree bpduguard enable command smartport macros, 229 (IOS), 81 SMDS (Switched Multimegabit Data Service) spanning-tree portfast command (IOS), 80 networks, 125 spanning-tree uplinkfast command (IOS), 83 speed bandwidth requirements in QoS configuring for PIX firewall scheme, 434 interfaces, 371 PIX firewall fixup, 375 for a connection, 19 priority in QoS, 433 single logical link, EtherChannel, 55 SNMP traps speed and duplex interface commands, sending for storm control, 235 IOS, 23 standards for use in (RFC 1232), 275 split horizon, 112 solar day, 507 SRST (Unified Survivable Remote Site Solaris Telephony) modules, 222 getting MAC address for a device, 13 SSH, 151, 419 group of physical Ethernet links bonded bandwidth requirements in QoS together (trunk), 56 scheme, 434 negotiation of EtherChannel links with in class maps, 436 Cisco switch via LACP, 60 giving priority to over all other SONET (synchronous optical network), 266 traffic, 420 source IP address of GRE tunnel, 153 QoS priority, 432 source IP address, load balancing with, 58 ssh command, 388 source MAC address, load balancing stabilizing properly sized production with, 58 network, 525 source port, load balancing with, 58 