Checking The Cable Status Using Tdr - Cisco WS-C6506 Software Manual

Chapter 20 Checking Status and Connectivity
Console> (enable)
This example shows how to display the PRBS counter values and the ports that are running the PRBS
test:
Console> (enable) show port prbs
Port PRBS state Error Counters
6/1 start 30
7/1 stop -
Console> (enable)

Checking the Cable Status Using TDR

You can check the status of the copper cables by using the time domain reflectometer (TDR). TDR is
supported on the following modules: WS-X6148-GE-TX, WS-X6148V-GE-TX, WS-X6548-GE-TX,
WS-X6548V-GE-TX, WS-X6548-GE-45AF, WS-X6748-GE-TX, WS-X6148A-GE-TX,
WS-X6148-GE-45AF, WS-X6148A-GE-45AF, WS-X6148A-RJ-45, and WS-X6148A-45AF. The TDR
detects a cable fault by sending a signal through the cable and reading the signal that is reflected back
to it. All or part of the signal can be reflected back by any number of cable defects or by the end of the
cable itself.
TDR can test cables up to a maximum length of 115 meters.
Note
Use TDR to determine if the cabling is at fault if you cannot establish a link. This test is especially
important when replacing an existing switch, upgrading to Gigabit Ethernet, or installing new cable
plants.
To start or stop the TDR test, perform this task in privileged mode:
Task
Step 1
Start or stop the TDR test.
Step 2
Display the TDR test counter information. show port tdr
This example shows how to start the TDR test on port 1 on module 2:
Console> (enable) test cable-diagnostics tdr start 2/1
TDR test started on port 2/1. Use show port tdr <m/p> to see the results
Console> (enable)
This example shows how to stop the TDR test on port 1 on module 2:
Console> (enable) test cable-diagnostics tdr stop 2/1
tdr cable-diagnostic test stopped on port 2/1.
Console> (enable)
This example shows the message that displays when the TDR test is not supported on a module:
Console> (enable) test cable-diagnostics tdr start 2/1
Feature not supported on module 2.
Console> (enable)
This example shows how to display the TDR test results for a port:
Console> (enable) show port tdr 2/1
TDR test last run on Mon, March 10 2003 at 1:35:00 pm
OL-8978-04
Command
test cable-diagnostics tdr {start | stop} mod/port
Catalyst 6500 Series Switch Software Configuration Guide—Release 8.7
Checking the Cable Status Using TDR
20-11