Table of Contents
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Chapter 32
Troubleshooting
The display shows the hop count, the IP address of the router, and the round-trip time in milliseconds
for each of the three probes that are sent.
Table 32-2
Character
*
?
A
H
N
P
Q
U
To end a trace in progress, 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 TDR
These sections contain this information:
•
•
Understanding TDR
You can use the Time Domain Reflector (TDR) feature to diagnose and resolve cabling problems. When
running TDR, a local device sends a signal through a cable and compares the reflected signal to the initial
signal.
TDR is supported only on 10/100 and 10/100/1000 copper Ethernet ports. It is not supported on SFP
module ports.
TDR can detect these cabling problems:
•
•
If one of the twisted-pair wires is open, TDR can find the length at which the wire is open.
OL-8603-04
Traceroute Output Display Characters
Description
The probe timed out.
Unknown packet type.
Administratively unreachable. Usually, this output means that an access list is
blocking traffic.
Host unreachable.
Network unreachable.
Protocol unreachable.
Source quench.
Port unreachable.
Understanding TDR, page 32-17
Running TDR and Displaying the Results, page 32-18
Open, broken, or cut twisted-pair wires—The wires are not connected to the wires from the remote
device.
Shorted twisted-pair wires—The wires are touching each other or the wires from the remote device.
For example, a shorted twisted pair can occur if one wire of the twisted pair is soldered to the other
wire.
Catalyst 2960 Switch Software Configuration Guide
Using TDR
32-17
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Troubleshooting
