51-16
Catalyst 3750-X and 3560-X Switch Software Configuration Guide
OL-21521-01
Chapter 51 Troubleshooting
Using Layer 2 Traceroute
Note Though other protocol keywords are available with the ping command, they are not supported in this
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 51-1 describes the possible ping character output.
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
Understanding Layer 2 Traceroute, page 51-16
Usage Guidelines, page 51-17
Displaying the Physical Path, page 51-17

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.
Tab le 51-1 Ping Output Display Characters
Character Description
!Each exclamation point means receipt of a reply.
.Each period means the network server timed out while waiting for a reply.
UA destination unreachable error PDU was received.
CA congestion experienced packet was received.
IUser interrupted test.
?Unknown packet type.
&Packet lifetime exceeded.