Information Processing Commands 31The tracert command is executed following this procedure: The system first sendsa packet with TTL as 1 and the first hop returns an ICMP error message indicatingthat the packet cannot be transmitted due to TTL timeout. and then the systemtransmits the packet again with TTL being set to 2 and the second hop returns TTLtimeout message similarly. This process continues until the packet reaches itsdestination. The purpose of such a process is to record the source addresses wherethese ICMP TTL timeout messages are sent so as to outline the path along whichthe IP packet can reach the destination.When a network fault is detected by using the ping command, tracert can be usedto locate the failure on the network.The output information of the command tracert includes IP addresses of all theGWs along the path to the destination. If some GW times out, “***” will beoutput.Example<3Com> tracert 18.26.0.115tracert to allspice.lcs.mit.edu (18.26.0.115), 30 hops max1 helios.ee.lbl.gov (128.3.112.1) 0 ms 0 ms 0 ms2 lilac-dmc.Berkeley.EDU (128.32.216.1) 19 ms 19 ms 19 ms3 lilac-dmc.Berkeley.EDU (128.32.216.1) 39 ms 19 ms 19 ms4 ccngw-ner-cc.Berkeley.EDU (128.32.136.23) 19 ms 39 ms 39 ms5 ccn-nerif22.Berkeley.EDU (128.32.168.22) 20 ms 39 ms 39 ms6 128.32.197.4 (128.32.197.4) 59 ms 119 ms 39 ms7 131.119.2.5 (131.119.2.5) 59 ms 59 ms 39 ms8 129.140.70.13 (129.140.70.13) 80 ms 79 ms 99 ms9 129.140.71.6 (129.140.71.6) 139 ms 139 ms 159 ms10 129.140.81.7 (129.140.81.7) 199 ms 180 ms 300 ms11 129.140.72.17 (129.140.72.17) 300 ms 239 ms 239 ms12 * * *13 128.121.54.72 (128.121.54.72) 259 ms 499 ms 279 ms14 * * *15 * * *16 * * *17 * * *18 ALLSPICE.LCS.MIT.EDU (18.26.0.115) 339 ms 279 ms 279 msInformationProcessing Commandsdisplay channel Syntaxdisplay channel [ channel-number | channel-name ]ViewAny view.Parameterchannel-number: Channel number, ranging 0 to 9. That is, the systemhas 10 channels.channel-name: Channel name.
