How to find Switch-Port with MAC- Address on a Cisco Catalyst Switch

Steps to find Switch-Port with MAC-address on Cisco Switch

If you want to find a Switch port on a Cisco Switch with a specific IP address, you can fallow the below steps. It is very easy to find out using below commands with shortcut pipe command.

Note these instructions are demonstrated on a Cisco IOS Software, Catalyst 4500 L3 Switch
Running Software (cat4500-ENTSERVICESK9-M), Version 12.2(46)SG, RELEASE SOFTWARE (fc1).

Lets start with an IP address on hand. If you have an IP address on hand quickly ping and check if the device is reachable. If device is reachable, then simply logon to one of your core Switches or Routers and issue a simple commad ” sh ip arp”.

Cisco-Switch>sh ip arp

Protocol  Address          Age (min)  Hardware Addr   Type   Interface

Internet  10.4.60.4               2   0027.0d73.4980  ARPA   Vlan1

Internet  10.4.60.11            -      40f4.ecb1.ce40     ARPA   Vlan1

Internet  10.9.0.67             111    0000.0c07.ac01  ARPA   Vlan1

Internet  10.90.12.7           111    0000.0c07.ac01  ARPA   Vlan1

Internet  10.9.130.21         109   0000.0c07.ac01  ARPA   Vlan1

Internet  10.15.0.167         111   0000.0c07.ac01   ARPA   Vlan1

Internet  10.90.130.22       112  0000.0c07.ac01   ARPA   Vlan1

Internet  10.90.130.21        99   0000.0c07.ac01    ARPA   Vlan1

Internet  10.90.130.29       111   0000.0c07.ac01   ARPA   Vlan1

Internet  10.9.0.219       111  0000.0c07.ac01  ARPA  Vlan1

Or we can use Pipe command to get required IP address directly

Cisco-Switch# sh ip arp | i 10.90.0.219

Protocol  Address          Age (min)  Hardware Addr   Type   Interface
Internet  10.90.0.219        22   0000.0c07.ac01  ARPA   Vlan1

From the above results, you can know the MAC Address of for the device:

IP Address : 10.90.0.219

MAC Address : 0000.0c07.ac01 

Now, issue a show mac address-table command on the core Switch or Router. This will show the interface to which it is connected or through which it is learned.

Cisco-Switch>sh mac address-table | i 0000.0c07.ac01

   1    0000.0c07.ac01    DYNAMIC     Fa0/6

This indicates that the device is either connected to the port or though another Switch which is connected to the interface. If that port is connected to other Switch, go to that Switch and repeat the above steps until you find the port which is directly connected to the device.

Now open the running configuration of the interface from privilege mode and  find the configuration details.

Cisco-Switch#show run int fa0/6
Building configuration…
!

interface FastEthernet0/6
description ***Cisco ACS Server***
switchport access vlan 201
switchport mode access
spanning-tree portfast
!

Cisco-Switch#