How to Use a MAC Address to Find an IP Address

Finding an IP address from a Media Access Control (MAC) address is accomplished using the ARP command. ARP maps the physical MAC address with the IP. The MAC address is a unique, alphanumeric string programmed on a network card that identifies the computer. The IP address is the number assigned to the network card. Using ARP, the user can find an IP address from the MAC or vice versa.

Difficulty: Moderately Easy

Instructions

1. Click the Windows "Start" button and select "Run." In the textbox, type "cmd" and click the "Ok" button. This opens a DOS prompt.

2. Type "arp" in the command prompt. This gives you a list of options to use with the arp command.

3. Type "arp -a" in the command prompt. This lists a number of MAC addresses with the associated IP addresses. Since you have the MAC address, scroll down the list to find the associated IP address. The MAC address is shown in the "Physical Address" column with the IP address in the "Internet Address" column. An example of a table record is in Step 4.

4. Evaluate results. The following is an example of ARP output. The first column is the IP address. The second column is the MAC address, and the third is the type of IP assigned--static or dynamic.
   Internet address Physical Address Type
   
   192.168.0.1 01-a3-56-b5-ff-22 static

References

• Microsoft