How to see wich switch interface that associate to a certain device's IP or MAC address?

[satyaz]

Hi cisco experts!

So i'm a 4-months-old-Network Engineer which has a responsibility to troubleshoot end user's pc and cisco ip phone. Those devices connected to our access switch.

I have 2 questions : 

1. How to see wich switch interface that associate to a certain device's IP address?

2. How to see wich switch interface that associate to a certain device's MAC address?

Because usually there are problems with user pc for example, but i don't know which switch interface that i need to see. 

Any enlighment will be a huge help for me. Thx!

[Leo Laohoo]

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@satyaz wrote:

1. How to see wich switch interface that associate to a certain device's IP address?

2. How to see wich switch interface that associate to a certain device's MAC address?

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If the downstream client is "talking", then enable IP Device Tracking.

[Francesco Molino · Accepted solution]

Hi

On your core switch (the one hosting all svi, which are layer 3 interfaces), you can run the command sh ip arp x.x.x.x (ip address of your client).
This command will give you the mac address associated to that survive ip.

Then you can run: sh mac add add abcd.abcd.abcd (mac address you get previously).
This command will give you the interface where this mac is connected to. However, from the core switch, you will have first a port-channel or trunk interface going to your access switch. Then, once in this access switch, re-run the command and you'll get the final end user interface.

[satyaz]

God **bleep**, t works !

Thank you very much sir!

[Francesco Molino]

You're welcome!