Often times we need to find a machine's MAC address so that we can setup DHCP reservations, such as when installing a new server.
You can use a two-step technique:
1. PING the machine's IP address or NetBIOS name and get a reply.
2. Run the ARP -a command against the IP address to get the MAC.
<wait for reply, and then...>
arp -a 192.168.50.2
Interface: 192.168.50.7 --- 0x10003 Internet Address Physical Address Type 192.168.50.2 00-11-85-d4-2a-6d dynamic