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Time Domain Reflectometer (TDR) for Network Professional

As a network engineer/administrator, you would encounter the cabling problem of patch panel to host, patch panel to switch, switch to switch.

In these scenarios, you can determine whether switch or physical layer (Layer 1 ) issue or not before contacting to cabling contractor.

To do so, you can use below commands.

show interface
show interface counters
show interface counters errors

Moreover, you still can find the cabling issue with another testing method. That is Time Domain Reflectometer.

To test this in cisco switch, use below commands.

test cable tdr interface port number

show cable-diagnostics tdr interface port number

You will know how to use it from below sample pictures.

If you are testing FastEthernet, Pair A and Pair B result must be Normal.
If you are testing GigabitEthernet , all Pair must be Normal.

Other than that result, you need to find out where is the distance that cable becoming fault.

The approximate cable fault distance is shown in result.

Yes, I believe you know the basic of TDR now.

This feature is include not only on Cisco Switch but also you can find in other brand switch like juniper, hp and dell.

If you want to know more about this in details, please go and read from below link. 

Have a good time.
(Be knowledgeable, pass it on then)


  1. There are miscellaneous expenditures in the production of the Reflectometry.
    The producers, the studio executives and the Reflectometry can monitor the Weekly Cost Report to get familiar with how much is been spent in comparison to the approved budget.
    More in fo: Reflectometry

  2. Hi...You were told to run away. Soak the place, and light the flame pay the price for your betrayal. Your betrayal, your betrayal!Read more-Reflectometry

  3. Hi admin,
    I really like it, I have also a blog which is related with you, which is about Reflectometry.
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