MAC Address

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

NIC turns data into an electrical signal that can be transmitted over the network. MAC addresses are used as a network address for most IEEE 802 network technologies, including Ethernet and WiFi.

MAC addresses are most often assigned by the manufacturer of a network interface controller (NIC) and are stored in its hardware, such as the card’s read-only memory or some other firmware mechanism. If assigned by the manufacturer, a MAC address usually encodes the manufacturer’s registered identification number and may be referred to as the burned-in address(BIA).

It may also be known as an Ethernet hardware address (EHA), hardware address or physical address.

Example of a MAC address for an Ethernet NIC: 00:0a:95:9d:68:16.
Some well-known manufacturers of network adapters or NICs are Dell, Belkin, Nortel and Cisco. These manufacturers all place a special number sequence (called the Organizationally Unique Identifier or OUI) in the MAC address that identifies them as the manufacturer.

The OUI is typically right at the front of the address. For example, consider a network adapter with the MAC address “00-14-22-01-23-45”. The OUI for the manufacture of this router is the first three octets – “00-14-22”. Here are the OUI for some well-known manufacturers.

Dell: 00-14-22
Nortel: 00-04-DC
Cisco: 00-40-96
Huawei: 00-18-82
ZTE: 00:19:C6
Alcatel Lucent: 00:1A:F0
Belkin: 00-30-BD
Vodafone: 00:24:89
Qualcomm: 00:24:89
Samsung: 00:E0:64
Apple: 00:F4:B9

You can know more on OUI Manufacture codes at WireShark.
The next time you go shopping, check the MAC address as part of your verification.