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MAC Address

A unique identifier assigned to a network interface controller (NIC) for use as a network address in communications within a network segment.

AbbreviationMAC
Categorynetwork

Overview

A Media Access Control (MAC) address is a 'burned-in' hardware address. It is 48 bits long, usually represented as six groups of two hexadecimal digits (e.g., 00:1A:2B:3C:4D:5E).

Structure

  • Organizationally Unique Identifier (OUI): The first 24 bits, identifying the manufacturer.
  • NIC Specific: The last 24 bits, assigned by the manufacturer to be unique.

Role in Networking

MAC addresses operate at the Data Link Layer (Layer 2). They are used by switches to deliver frames to the correct physical device on a local network.

Related Terms

Data Link LayerIP AddressARP