Specifications

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Catalyst 2950 and Catalyst 2955 Switch Software Configuration Guide
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Chapter29 Troubleshooting
Diagnosing Connectivity Problems
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 29-1 describes the possible ping character output.
To terminate a ping session, enter the escape sequence (Ctrl-^ X by default). You enter the default by
simultaneously pressing and releasing the Ctrl, Shift, and 6 keys, and then pressing the X key.
Using Layer 2 Traceroute
This section describes this information:
• Understanding Layer 2 Traceroute, page 29-12
• Switches Supporting Layer 2 Traceroute, page 29-13
• Usage Guidelines, page 29-13
• Displaying the Physical Path, page 29-14
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 determines 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.
Table 29-1 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.
U A destination unreachable error PDU was received.
C A congestion experienced packet was received.
I User interrupted test.
? Unknown packet type.
& Packet lifetime exceeded.