Using Layer 2 Traceroute; Understanding Layer 2 Traceroute - Cisco Catalyst 2928 Software Configuration Manual

Using Layer 2 Traceroute

Though other protocol keywords are available with the ping command, they are not supported in this
Note
release.
This example shows how to ping an IP host:
Switch# ping 172.20.52.3
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echoes to 172.20.52.3, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/2/4 ms
Switch#
Table 33-1
Table 33-1
Character
!
.
U
C
I
?
&
To end a ping session, enter the escape sequence (Ctrl-^ X by default). Simultaneously press and release
the Ctrl, Shift, and 6 keys and then press the X key.
Using Layer 2 Traceroute
These sections contain this information:
•
•
•

Understanding Layer 2 Traceroute

The Layer 2 traceroute feature allows the switch to identify the physical path that a packet takes from a
source device to a destination device. Layer 2 traceroute supports only unicast source and destination
MAC addresses. It finds the path by using the MAC address tables of the switches in the path. When the
switch detects a device in the path that does not support Layer 2 traceroute, the switch continues to send
Layer 2 trace queries and lets them time out.
The switch can only identify the path from the source device to the destination device. It cannot identify
the path that a packet takes from source host to the source device or from the destination device to the
destination host.
Catalyst 2928 Switch Software Configuration Guide
33-14
describes the possible ping character output.
Ping Output Display Characters
Description
Each exclamation point means receipt of a reply.
Each period means the network server timed out while waiting for a reply.
A destination unreachable error PDU was received.
A congestion experienced packet was received.
User interrupted test.
Unknown packet type.
Packet lifetime exceeded.
Understanding Layer 2 Traceroute, page 33-14
Usage Guidelines, page 33-15
Displaying the Physical Path, page 33-15
Chapter 33 Troubleshooting
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