Furthermore, not all devices will have the same output, but they will all give you IP and MAC address at least. It is just the interface the MAC address comes from.

Don’t be fooled by the interface, this is not necessarily the interface where the device is connected. Here, we are looking at the MAC address, the one with the notation. Dallas-CORE# show ip arp | include 10.43.11.91 Imagine our target IP is 10.43.11.91, we can do the following. We need to inspect the device and get the MAC address from it.Īfter pinging, you can check the ARP table with show ip arp | include. If it does not ping, there is nothing we can do. Instead, we ensure it is there by pinging it: we wake him up. If the device was silent, the switch may have removed its MAC address from the ARP table. This is important because the device might have been silent for a while. Now that we are on the correct device, we need to ping our target IP address. If you connect to any other device, it might not have this detail in the ARP table, and you won’t go any further. Furthermore, it is a device in that network you (as a network administrator) have access to.īeing in the same network means being able to see MAC addresses, and knowing MAC addresses allows you to locate the devices.

This device is the one all devices in the network sends traffic to when the want to communicate with the outside world. It is mandatory to connect to the default gateway. It is important we get the first step straight, otherwise we won’t go far. Finding a device, the details Connect to the default gateway

Otherwise, it might be behind a switch which is not manageable, or on a virtualized host like VMware ESXi.Īnd this is it! Still confused? Don’t worry, we will cover all these steps in detail just below. Use show mac address-table interface and check how many MAC addresses you see. If you see no output from the previous step, probably the device is right there on this port.In this case, connect to that switch and repeat from Step #3. If this command outputs something, it will also tell you the management address of the switch connected. Here, use the port we found in the previous step. Check if you have some switches connected to that port with show cdp neighbor detail.

Use show mac address-table address, where the is the one we found in the previous step.Here, you will see the MAC address of such device, then: Use show ip arp | include, where is the IP of your target device.Connect to the device that acts as default router for the target network and ping your target IP.Steps to find a device in a network using the MAC address table and the ARP table.

How to check cisco router mac address