What is a MAC Address?

A Media Access Control address or MAC address is a unique code assigned to every piece of hardware that connects to the Internet. Internet capable phones, Network Interface Cards for desktop or notebook computers, Wireless Access Cards, and even some memory cards are among the devices that are assigned MAC addresses.

When a manufacturer creates a network capable piece of hardware they will assign the MAC address which will usually begin with a code that is tied to the manufacturer. The MAC address will be unique to every device, even two devices of the same type.

A device’s MAC address is composed of six pairs of hexadecimal numbers. The numbers are separated by colons as in the following example:

6E:51:F5:c1:11:00

MAC addresses are used at the data link layer of the OSI hardware model to allow packets to be passed directly between devices on a network. This helps to ensure that the data is sent to a physical device before being decoded and/or manipulated by a device.

A MAC address is similar to an IP address that the device also receives in that it ensures each device is unique and allows data to be passed among hardware devices. An IP address allows two devices to communicate across a LAN or network environment — normally IP addresses should also be unique and will allow the exchange of data.