A mechanism operating at the data link layer of local area networks which manages access to the communications channel (medium). It forms the lower layer of the IEEE data link layer (OSI layer 2) which complements the Logical Link Control (LLC). MAC is a media-specific protocol within the IEEE 802 specifications.
A method of controlling access to a transmission medium (e.g., Ethernet, Token Ring, and FDDI).
The MAC Address (Media Access Control) is the hardware address of a network device (e.g. network card, switch). The MAC address is unique world-wide. It consists of 48 bits identifying the manufacturer of the device (24 bits) and interfaces used by the manufacturer. This allows for a unique identification of the device in the network. The MAC address is often used to generate software license keys.