What is a MAC address?

Whether you work in a wired network office or a wireless one, one thing is common for both environments: It takes both network software and hardware (cables, routers, etc.) to transfer data from your computer to another—or from a computer thousands of miles away to yours.

And in the end, to get the data you want right to YOU, it comes down to addresses.

So not surprisingly, along with an IP address (which is networks software), there’s also a hardware address. Typically it is tied to a key connection device in your computer called the Network Interface Card, or NIC. The NIC is essentially a computer circuit card that makes it possible for your computer to connect to a network.

A Network Interface Card turns data into an electrical signal that can be transmitted over the network.

NIC (Network Interface Connection – Your WiFi adapter) and MAC Addresses

Every NIC has a hardware address that’s known as a MAC, for Media Access Control. Where IP addresses are associated with TCP/IP (networking software), MAC addresses are linked to the hardware of network adapters.

A MAC address is given to a network adapter when it is manufactured. It is hardwired or hard-coded onto your computer’s network interface card (NIC) and is unique to it. Something called the ARP (Address Resolution Protocol) translates an IP address into a MAC address. The ARP is like a passport that takes data from an IP address through an actual piece of computer hardware.

Once again, that’s hardware and software working together, IP addresses and MAC addresses working together.

For this reason, the MAC address is sometimes referred to as a networking hardware address, the burned-in address (BIA), or the physical address. Here’s an example of a MAC address for an Ethernet NIC: 00:0a:95:9d:68:16.

As you’ve probably noticed, the MAC address itself doesn’t look anything like an IP address (see yours here). The MAC address is a string of usually six sets of two-digits or characters, separated by colons.

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 other some well-known manufacturers.

Dell: 00-14-22
Nortel: 00-04-DC
Cisco: 00-40-96
Belkin: 00-30-BD