Depending on the Cisco platform, sometimes the command is listed in either form. On that device issue one of the following commands (where mac-address is the hardware address from previous step). The output should look similar to below, and give you the mac-address of the device (listed below in bold). Log into the routing device, and issue the following command (where ipaddress is the ip address of the host you are trying to locate: show ip arp *ipaddress* Sometimes it is a " Router on a Stick", where the Layer 2 VLANs are being trunked up to the router for the Layer 3 decisions. The output should look similar to below, the port you are looking for should be listed as the Destination Port: LYKINS-1861#show mac-address-table address 28cf.da1d.1b05ĭestination Address Address Type VLAN Destination PortĢ8cf.da1d.1b05 Dynamic 10 **FastEthernet0/1/1**įind out what device is doing the routing for this switch (you may have to look at the network documentation). Show mac-address-table address *mac-address* show mac address-table address *mac-address* Now issue one of the following commands (where mac-address is the hardware address from previous step).
Sometimes it is a 'Router on a Stick', where the Layer 2 VLANs are being trunked up to the router for the Layer 3 decisions.
Protocol Address Age (min) Hardware Addr Type Interface On a Layer 2 switch: Find out what device is doing the routing for this switch (you may have to look at the network documentation). The output should look similar to below, and give you the mac-address of the device (I've highlighted the mac-address below in bold). Log into the switch and issue the following command (where ipaddress is the ip address of the host you are trying to locate: show ip arp *ipaddress* In either case, the commands are the same, just run on two different boxes for the layer 2 switch. However on a layer 2 switch, you have to log into both the switch and whatever device is doing the routing to locate the port. On a layer 3 switch, the port can be found by using a few simple commands on the device. That is to say, is the switch only switching and relaying traffic on to a different device for routing, or, is it doing the routing decisions itself via SVIs (switched virtual interfaces). The answer depends on whether the switch is a Layer 2 or a Layer 3 switch.