bleshooting, 516-520 System (see TACACS+) assuming nothing; proving terminal server break character, 514 everything, 518 terminators, 6 checking physical layer first, 518 testing mode (PIX interface), 378 don't look for zebras, 519 tftp-server command, 411 escalating to someone else, 520 thicknet cables, 6 finding out what changed, 517 thin-net cables, 6 isolating the problem, 519 three-tier switched network, 43 Janitor Principle, 520 three-tiered architecture logging your actions, 517 corporate network, 473 performing a physical audit, 519 e-commerce web site, 478 remaining calm, 517 bridged, 479 in a team environment, 520 management network, 480 trunk (switchport mode), 37 routed, 480 trunk carrier, 266 thresholds (storm control), 234-238 trunk encapsulation, specifying on IOS rising and falling thresholds, 236 switch, 38 throughput (on digital links), 255 trunk ports, 25 time (see NTP) trunking time exceeded messages, 333 deciding which protocol to use, 36 timed updates, 112 protocols supported on Cisco time-division multiplexing (TDM), 267, 273 switches, 34 timeslots, 295 VTP (VLAN Trunking Protocol), 28, time-to-live (TTL), HSRP packets, 164 43-54 Token Ring networks, 3 trunks, 25, 33-42 support by OSPF, 125 configuring, 38-42 Top-N reports CatOS switches, 40 error-producing ports, 226 IOS switches, 38-40 most utilized ports, 226 connecting two switches, 25 topology database (EIGRP), 120 corporate network design, 476 route tag implementation, checking, 144 defined, 33 TOS (Type of Service) field, 422-425 how they work, 34 totally stubby area (TSA), OSPF, 123 choosing protocol, 36 trace keyword, 230 ISL, 35 traceroute command, allowing ICMP packet trunk negotiation, 37 types needed for, 332 Solaris VS. Cisco terminology, 56 traffic shaping, 426 TSA (totally stubby area), OSPF, 123 Index TTL (time-to-live), HSRP packets, 164 DLCIs (data link control identifiers), 301 tunnels, 150-162 status messages about, exchange through GRE (Generic Routing LMI, 307 Encapsulation), 151-162 VIP (Virtual IP) address, 164 acce