3Com 3032 Configuration Manual page 92

88 C 6: D
HAPTER ISPLAY AND
tracert command (Trace
Route Command)
D T
EBUGGING OOLS
!!!!!
--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
The trace route command helps to trace the current network path to a
destination. With
tracert
passes from the source address to the destination address can be displayed. It can
be used to check network connection and locate fault.
The command is executed as follows: first, send a packet with TTL 1, and
tracert
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
Display the path from the source
address to the destination
address
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
command. In the former example, network connection is correct, while in
tracert
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)
2 lilac-dmc.Berkeley.EDU (128.32.216.1)
3 ccngw-ner-cc.Berkeley.EDU (128.32.136.23)
4 ccn-nerif22.Berkeley.EDU (128.32.168.22)
5 128.32.197.4 (128.32.197.4)
6 131.119.2.5 (131.119.2.5)
7 129.140.70.13 (129.140.70.13)
8 129.140.71.6 (129.140.71.6)
9 129.140.81.7 (129.140.81.7)
10 nic.merit.edu (35.1.1.48)
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)
2 lilac-dmc.Berkeley.EDU (128.32.216.1)
command, all gateways by which the test packet
Command
tracert [ -a ip-address ] [ -f first_TTL ]
[ -m max_TTL ] [ -p port ] [ -q nqueries ]
[ -w timeout ] host
19 ms
40 ms 59 ms
59 ms 59 ms
99 ms
139 ms 239 ms
220 ms 199 ms
239 ms 239 ms
0 ms
19 ms 0 ms
39 ms 39 ms 19 ms
39 ms 40 ms
39 ms 39 ms 39 ms
59 ms
59 ms
99 ms 80 ms
319 ms
199 ms
239 ms
0 ms 0 ms
19 ms 19 ms 19 ms
39 ms