Command Reference Guide

3Com Router 3000 Ethernet Family
Command Reference Guide
Chapter 1 System Maintenance and Management
Commands
3Com Corporation
1-13
first_TTL is 1.
max_TTL is 30.
port is 33434.
nqueries is 3.
timeout is 5 seconds.
The following is how a tracert operates:
1) Tracert sends a packet with TTL value of 1.
2) The fist hop sends back an ICMP TTL Expired message.
3) Tracert resends the packet with TTL value of 2.
4) The second hop sends back an ICMP TTL Expired message when the packet
arrives.
This process continues until the packet reaches its destination. By doing this, the
source station obtains the source address in every returned ICMP TTL Expired
message to draw the path for the IP packet to reach its destination.
After detecting a fault with the ping command, you can use the tracert command to
locate the problem.
The output of the command tracert includes IP addresses of all the gateways along the
path to the destination. If a gateway times out, asterisks (***) are output.
Example
<3com> tracert 18.26.0.115
tracert to allspice.lcs.mit.edu (18.26.0.115), 30 hops max
1 helios.ee.lbl.gov (128.3.112.1) 0 ms 0 ms 0 ms
2 lilac-dmc.Berkeley.EDU (128.32.216.1) 19 ms 19 ms 19 ms
3 lilac-dmc.Berkeley.EDU (128.32.216.1) 39 ms 19 ms 19 ms
4 ccngw-ner-cc.Berkeley.EDU (128.32.136.23) 19 ms 39 ms 39 ms
5 ccn-nerif22.Berkeley.EDU (128.32.168.22) 20 ms 39 ms 39 ms
6 128.32.197.4 (128.32.197.4) 59 ms 119 ms 39 ms
7 131.119.2.5 (131.119.2.5) 59 ms 59 ms 39 ms
8 129.140.70.13 (129.140.70.13) 80 ms 79 ms 99 ms
9 129.140.71.6 (129.140.71.6) 139 ms 139 ms 159 ms
10 129.140.81.7 (129.140.81.7) 199 ms 180 ms 300 ms
11 129.140.72.17 (129.140.72.17) 300 ms 239 ms 239 ms
12 * * *
13 128.121.54.72 (128.121.54.72) 259 ms 499 ms 279 ms
14 * * *
15 * * *
16 * * *
17 * * *
18 ALLSPICE.LCS.MIT.EDU (18.26.0.115) 339 ms 279 ms 279 ms