how to find out what port on the switch a device is connected when you know the device mac address

From time to time, you want find out what port on switch is a computer, printer, server, or other network device is connected when you have the MAC Address of the device. Possibly a device is sending broadcast storm or misbehaving on the network and you want disconnect it or you want punt specific device on a VLan.

Here is the command to issue on your Cisco Switch to find the source port of the MAC address


CoreSwitch#show mac address-table | include 00c0.ee86.58ed
1 00c0.ee86.58ed DYNAMIC Gi1/0/21
CoreSwitch#

On the above example, we see that the the device with the MAC Address 00c0.ee86.58ed is connected on port 21 of CoreSwitch and it’s Dynamic which means it’s learned MAC Address, not manually entered.

Publisher: abdirahman isse

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