Find port by Device Mac Address –
At times, network and IT admins are faced with the challenge to find out which device is connected to which port of the catalyst Switch or which port of the switch is a specific device mac address coming from.
The below command helps to view which port the cisco show MAC address is being learned from.
The command syntax is –
SWITCH# show mac-address-table
MAC Address table
Vlan Mac Address Type Ports
– ——————— ————- ——–
1 0009.aabb.3ad2 DYNAMIC Fa0/3
1 0009.aabb.06e9 DYNAMIC Fa0/10
1 0009.5bdc.af04 DYNAMIC Fa0/15
1 00e0.ba2c.acd1 DYNAMIC Fa0/16
1 00e0.ab3c.3e6f DYNAMIC Fa0/22
Total Mac Addresses for this criterion: 5
With the command, you can figure out which MAC address is on which port. The mac address or CAM table shows the Vlan associated with the port, MAC being learned on the port (i.e. mac address of the connected device) and port number. Only ports which have the device connected and active will show the mac address detail.
If you know the switch port you can use the following command
switch# show mac-address-table | include Fa0/5
or if you know the mac address and want to know which port the mac address is coming from, use the following command
switch# show mac-address-table | include 0009.aabb.06e9
With the above command, one can figure out which Mac address is on which port of catalyst switch. Only ports which have a device connected and active will show the mac address detail.
Related – Ways to find MAC address