MAC Address

A media access control address (MAC address) is a unique identifier assigned to network interfaces for communications on the physical network segment.

MAC addresses are used as a network address for most IEEE 802 network technologies, including Ethernet.

Will MAC Address be run out?
How many addresses can be produced out of the current MAC address system?

IPv4 = 232 = 4,294,967,296

MAC = 246 = 70,368,744,177,664

Even if MAC address is to be run out, it is the address used on Data link layer, which means MAC address can be duplicated if not placed on the same subnet segment.

Per OUI　224 = 16,777,216

For example, Nintendo has invented a great product called Nintendo DS which requires a MAC address to communicate via Wifi. Even only in Japan, more than 20 million Nintendo DS have been sold, which means only 1 OUI address is not enough.

That is the reason why Nintendo owns multiple OUI address range for its popular DS products.

Links

 * http://standards.ieee.org/regauth/oui/oui_public.txt


 * http://standards.ieee.org/develop/regauth/oui/public.html