Using test cable-diagnostics tdr

[andre.roberge]

Hi, 

For some reason when I ran the command test cable-diagnostics on some cisco 3750x the test never complete. 

Here is the command:

test cable-diagnostics tdr interface gigabitEthernet 1/0/44
TDR test started on interface Gi1/0/44
A TDR test can take a few seconds to run on an interface
Use 'show cable-diagnostics tdr' to read the TDR results.

When I run the show cable-diagnostics the test is never completed.

show cable-diagnostics tdr interface gigabitEthernet 1/0/44

TDR test last run on: December 24 16:33:59

Interface Speed Local pair Pair length        Remote pair Pair status
--------- ----- ---------- ------------------ ----------- --------------------
Gi1/0/44  1000M Pair A     N/A                N/A         Not Completed       
                Pair B     N/A                N/A         Not Completed       
                Pair C     N/A                N/A         Not Completed       
                Pair D     N/A                N/A         Not Completed

It does work on some 3750x switches and does not work on others switches, they all are Cisco 3750x with version 15

Any idea on where to find a solution?

[Leo Laohoo]

Result like that could mean a few things:  

1.  In extreme cases, give it another 30 seconds.  It happens when your cable is that bad.  You can verify if this is working or not by un-patching the cable from the switch and see if you get some kind of result with "0" distance value. 

2.  IOS bug.  State the IOS on the appliance.  I wouldn't attempt to run TDR with IOS version 15.(1)SE (all of them) as this particular version is really bad.  15.0(2)SE2 TDR is "broken".  

3.  Possible hardware failure.  Re-patch the port to a different port on the switch and see if you're getting the same response.