Understanding cable diagnostics output

[ja raju]

Hi guys,

I have this output from a cable diagnostic test that I did. How do I pinpoint at which end the pair is open? Is it at the closet end or user end?

show cable-diagnostics tdr int f0/39

TDR test last run on: January 27 10:45:54

Interface Speed Local pair Pair length        Remote pair Pair status

--------- ----- ---------- ------------------ ----------- --------------------

Fa0/39    auto  Pair A     6    +/- 1  meters N/A         Open                <===

                Pair B     39   +/- 1  meters N/A         Open                <===

                Pair C     N/A                N/A         Not Supported      

                Pair D     N/A                N/A         Not Supported      

Thanks in advance.

[Leo Laohoo]

"open" means the far end has nothing connected to it.

"normal" means good and something is connected to the far end.

"short" means short circuit.

"Impedance Mismatched" means a Cat5 cable has been joined with a Cat6 cable.

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[ja raju]

How do I know how far from the switch is it open/broken?

[Leo Laohoo]

How do I know how far from the switch is it open/broken?

In your output, under "Pair" is the length.  Do you see that you have two disparate distance?  It means you have a break somewhere.

[ja raju]

So there's no way to see exactly where it's broken?

Thanks anyway...

[Leo Laohoo]

6 and 39 metres from the switch's port.  +1/-1 metre error.

[ja raju]

You mean at both locations?

[Leo Laohoo · Accepted solution]

You mean at both locations?

Look at the output of the "sh cable test tdr".

Pair A is detected to be 6 metres away from the switch port (+/- 1 metre error).  Pair B is detected to be 39 metresaway from the switch port (+/- 1 metre error).

Pair C and Pair D is not tested because your interface is a fastethernet interface.

[ja raju]

I take that as a yes

Thanks.