A tool called GetMAC returns the media access control (MAC) address and list of network protocols associated with...
each address for all network cards in each computer, either locally or across a network. This can be useful when you want to enter the address into a sniffer, or if you need to know what protocols are currently in use on a computer.
To find the MAC address for a remote computer, type this at the command prompt: GetMAC /S
Please make sure that you have admin permission on the remote computer otherwise GetMAC fails.
For more options on GetMAC, type GETMAC /? at the command prompt.