test cable-diagnostics tdr
To use Time Domain Reflectometry (TDR) technology to diagnose the quality and characteristics of a copper cable attached to a port, use the test cable-diagnostics tdr Privileged EXEC mode command.
test cable-diagnostics tdr interface interface-id
interface-id—(Optional) Specifies an Ethernet port ID.
Privileged EXEC mode
This command does not work on fiber ports (if they exist on the device). The port to be tested should be shut down during the test, unless it is a combination port with fiber port active. In this case, it does not need to be shut down, because the test does not work on fiber ports.
The maximum length of cable for the TDR test is 120 meters.
Example 1 - Test the copper cables attached to port gi1/0/1 (a copper port).
switchxxxxxx# test cable-diagnostics tdr interface gi1/0/1
Cable is open at 64 meters
Example 2 - Test the copper cables attached to port 2 (a combo port with fiber active).
switchxxxxxx# test cable-diagnostics tdr interface gi1/0/2
Fiber ports are not supported