Which tool can we use to trace port?

[wfqk]

Hi wall jack --RJ45 has cable to a switch that is connected a lot cables. I want to know the jack port on the wall connect to which port of switch. what is a good way to do it? Thank you

[chrihussey]

Plug a laptop or other device into the jack and look for the device's MAC address on the switch:

The command varies slightly between different platforms but:

"sh mac address-table address xxxx.xxxx.xxxx"

It will tell you which port it is on.

Hope this helps

[Felipe A. Amaya]

You can search for tools which can also help provide those statistics. Some are pretty inexpensive. 

[Rafael Carvallo · Accepted solution]

Hi,

There's a couple of ways you could do this:

1.- Plug a device with a known MAC and see the mac-address table of the switch (already mentioned by someone above), it's great if you have access to the switch and it's a single switch for all the ports, using the following command for instance:

show mac address-table known-MAC-address

2.- Use mac traceroute, if you have a L2 distribution-access topology, you could log into one of the switches and trace the port where the MAC is even if it's several hops away (as in, not in the switch where you're doing the actual traceroute). This still would require you to plug a device with a known address into the outlet (you'd do the traceroute towards this MAC) and this requires CDP enabled on all the switches.

More info: 

https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst6500/ios/12-2SX/configuration/guide/book/l2trace.html

http://www.ciscozine.com/how-to-trace-mac-address/

3.- You can use a cable testing tool like this one: 

www.flukenetworks.com/datacom-cabling/copper-testing/IntelliTone-Pro-Toner-and-Probe

On this case you'd need someone with the signal generator (toner) going from outlet to outlet plugin it, then someone in the telecomm room would use the probe to check what cable is tied to that plug, this way you can write down the port number where said cable is terminated. This doesn't require you to have access to the switch's (switches) console. 

4.- If you have a list of outlets vs mac-address you could do options 1 or 2 without pluging things, just by checking the actual list, I am talking about something like this:

Device Name --- Device MAC --- Where is it connected
CEO's PC   ---  AAAA.BBBB.CCCC --- Outlet5 floor3
Sr. Eng     -----  AAAA.BBBB.DDDD --- Outlet6 floor10

Assuming the list is up to date it should be quite easy, also if you know how to program using python or using ansible you could automate 100% of this:

1. Feed the list to the automation app you build (or the ansible's playbook)
2. Make it iterate over each item in the list
3. For each item do option #1 (check the mac address table)
4. Make it report its findings

Hope this helps

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