3Com 10014299 manual Following command can be executed in any command modes, Tracert command

88CHAPTER 6: DISPLAY AND DEBUGGING TOOLS

!!!!!

--2.0.0c91.f61f IPX ping statistics-- 5 packets transmitted

5 packets received

0% packet loss

round-trip min/avg/max = 1/2/3 ms

tracert command (Trace The trace route command helps to trace the current network path to a Route Command) destination. With tracert command, all gateways by which the test packet

passes from the source address to the destination address can be displayed. It can be used to check network connection and locate fault.

The tracert command is executed as follows: first, send a packet with TTL 1, and the first hop returns an ICMP error message, indicating that this packet cannot be sent (for TTL timeout). Then, this packet is re-sent with TTL added by 1 (namely 2). Similarly, the next hop returns TTL timeout. In this way, the procedure continues till the destination is reached. The purpose of these procedures is to record the source address of each ICMP TTL timeout message, so as to provide the path by which an IP packet has to pass to reach the destination address.

The following command can be executed in any command modes:

Table 66 tracert command

Operation	Command
Display the path from the source	tracert [ -a ip-address] [ -f first_TTL ]
address to the destination	[ -mmax_TTL ] [ -pport ] [ -qnqueries ]
address	[ -wtimeout ] host

Please see relevant chapters in the 3Com Router Command Reference Guide for detailed meanings of various options and parameters.

Described below are two examples to analyze the network connection with tracert command. In the former example, network connection is correct, while in the latter, network connection is faulty.

[Router]tracert 35.1.1.48
Trace route to nis.nsf.net (35.1.1.48), 30					hops			max,		56	byte packet
1	helios.ee.lbl.gov (128.3.112.1)		19 ms			19 ms			0	ms
2	lilac-dmc.Berkeley.EDU (128.32.216.1)				39		ms		39	ms	19 ms
3	ccngw-ner-cc.Berkeley.EDU (128.32.136.23)							39	ms	40 ms		39 ms
4	ccn-nerif22.Berkeley.EDU (128.32.168.22)						39 ms			39	ms	39 ms
5	128.32.197.4 (128.32.197.4)	40 ms		59	ms			59	ms
6	131.119.2.5 (131.119.2.5)	59 ms	59 ms				59	ms
7	129.140.70.13 (129.140.70.13) 99 ms			99			ms		80 ms
8	129.140.71.6 (129.140.71.6)	139 ms		239			ms		319	ms

9129.140.81.7 (129.140.81.7) 220 ms 199 ms 199 ms

10nic.merit.edu (35.1.1.48) 239 ms 239 ms 239 ms

The above results indicate which gateways (1~9) are passed from the source address to the destination address. That is very useful to network analysis.

[Router]tracert 18.26.0.115
traceroute 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