Alcatel OS-LS-6224 User Manual page 642

4
Command Line Interface
Command Usage
The traceroute command takes advantage of the error messages generated
by the devices when a datagram exceeds its time-to-live (TTL) value.
The traceroute command starts by sending probe datagrams with a TTL
value of one. This causes the first device to discard the probe datagram and
send back an error message. The traceroute command sends several probes
at each TTL level and displays the round-trip time for each.
The traceroute command sends out one probe at a time. Each outgoing
packet may result in one or two error messages. A "time exceeded" error
message indicates that an intermediate device has seen and discarded the
probe. A "destination unreachable" error message indicates that the
destination node has received the probe and discarded it because it could not
deliver the packet. If the timer goes off before a response comes in, the
traceroute command prints an asterisk (*).
The traceroute command terminates when the destination responds, when
the maximum TTL is exceeded or when the user interrupts the trace by
pressing Esc.
Example
The following example discovers the routes that packets will actually take when
traveling to their destination.
Console> traceroute umaxp1.physics.lsa.umich.edu
Type Esc to abort.
Tracing the route to umaxp1.physics.lsa.umich.edu (141.211.101.64)
1 i2-gateway.stanford.edu (192.68.191.83)
2 STAN.POS.calren2.NET (171.64.1.213) 0 msec 0 msec 0 msec
3 SUNV--STAN.POS.calren2.net (198.32.249.73) 1 msec 1 msec 1 msec
4 Abilene--QSV.POS.calren2.net (198.32.249.162)
5 kscyng-snvang.abilene.ucaid.edu (198.32.8.103) 33 msec 35 msec 35 msec
6 iplsng-kscyng.abilene.ucaid.edu (198.32.8.80)
7 so-0-2-0x1.aa1.mich.net (192.122.183.9)
8 atm1-0x24.michnet8.mich.net (198.108.23.82)
9 * * *
10 A-ARB3-LSA-NG.c-SEB.umnet.umich.edu (141.211.5.22) 58 msec 58 msec 58
msec
11 umaxp1.physics.lsa.umich.edu (141.211.101.64)
The following table describes significant fields shown above.
Field
1
i2-gateway.stanford.edu
192.68.191.83
1 msec 1 msec 1 msec
618
Description
Indicates the sequence number of the device in the path to the host.
Host name of this device.
IP address of this device.
Round-trip time for each probe sent.
0 msec 0 msec 0 msec
1 msec 1 msec 1 msec
47 msec 45 msec 45 msec
56 msec 53 msec 54 msec
56 msec 56 msec 57 msec
62 msec 63 msec 63 msec