cable diagnostics test

[tedauction]

Hello, on some of our switches when we run the cable diagnostics test, it tell us that Cable Diag is not available at 100Mbps and 10Mbps. Other switches run the test fine when the interface is only 100Mbps.

Is this simply due IOS limitations ?

Myswitch#test cable tdr interface Gig3/0/22
Link state may be affected during TDR test
TDR test started on interface Gi3/0/22
A TDR test can take a few seconds to run on an interface
Use 'show cable-diagnostics tdr' to read the TDR results.
Myswitch#show cable-diag tdr int gi3/0/22
TDR test last run on: March 03 10:46:27

Interface Speed Local pair Pair length Remote pair Pair status
--------- ----- ---------- ------------------ ----------- --------------------
Gi3/0/22 auto Pair A N/A N/A N/A
Pair B N/A N/A N/A
Pair C N/A N/A N/A
Pair D N/A N/A N/A
Cable Diag is not available at 100 Mbps and 10 Mbps******************************

[Reza Sharifi]

Hi,

Correct.  This command is not consistent across multiple different IOS versions.  If you really need to test cables, I would not relay on this command as a good tool.  Use the correct tool for it.

HTH

[Ganesh Hariharan]

Hi,

A time-domain reflectometer (TDR) is an electronic instrument used to characterize and locate faults in metallic cables (for example, twisted wire pairs, coaxial cables)

TDR works on 10/100/1000BaseTx.TenGigabitEthernet copper port DOES NOT (YET) support TDR.

Hope it Helps..

-GI

[carlos.perez1]

Hi Experts

I have connected IP phones on my Catalyst 2960x switch and I want to run a test to the port, checking documentation I found the following commands,

SW_01#test cable-diagnostics tdr interface g1/0/5
Link state may be affected during TDR test
TDR test started on interface Gi1/0/5
A TDR test can take a few seconds to run on an interface
Use 'show cable-diagnostics tdr' to read the TDR results.
SW_Despacho_01#show cable-diagnostics tdr int g1/0/5
TDR test last run on: July 18 16:22:58

Interface Speed Local pair Pair length Remote pair Pair status
--------- ----- ---------- ------------------ ----------- --------------------
Gi1/0/5 auto Pair A N/A N/A N/A
                    Pair B N/A N/A N/A
                    Pair C N/A N/A N/A
                    Pair D N/A N/A N/A
Cable Diag is not available at 100 Mbps and 10 Mbps
SW_01#

I have connected IP phones on my Catalyst 2960x switch and I want to run a test to the port, checking documentation I found the following commands,

The phones are Cisco 7811 and I wanted to validate if you have a damaged pair, because the phone at times takes time to dial calls,

I faced a similar problem but with Meraki Switches and I saw that the data pairs were bad, inside the Meraki Dashboard there is a part to do the wiring test and it helped me a lot, but with Catalyst it is not like that. I only found those commands,

Anyone know why that data comes out. N / A when I run the cable test.

I look forward to your valuable help

Regards,

Carlos P.