Full form: Media Access Control Address
Also known as: Media Access Control Address, hardware address, physical address, burned-in address, BIA
Quick Definition
A 48-bit hardware identifier burned into every network interface card.
A MAC address is a 48-bit (6-byte) hardware address assigned to a network interface card (NIC) by its manufacturer. It is written in hexadecimal, separated by colons or hyphens (e.g., 00:1A:2B:3C:4D:5E). Switches use MAC addresses to forward frames within a local network. The first three bytes identify the manufacturer (OUI) and the last three are unique to the device.
When SW1 receives a frame from PC1, it records PC1's MAC address against the port it arrived on in its MAC address table, so future frames destined for PC1 are sent only to that port.
MAC addresses operate at Layer 2. Routers do not forward frames based on MAC addresses — they strip the Layer 2 header and use the Layer 3 IP address.
A Layer 2/3 protocol that maps known IP addresses to unknown MAC addresses.
The set of all devices that receive a Layer 2 broadcast frame.
A network segment where two devices can cause a collision if they transmit simultaneously.
A logical segmentation of a switch network into separate broadcast domains.
A MAC address is a 48-bit (6-byte) hardware address assigned to a network interface card (NIC) by its manufacturer. It is written in hexadecimal, separated by colons or hyphens (e.g., 00:1A:2B:3C:4D:5E). Switches use MAC addresses to forward frames within a local network. The first three bytes identify the manufacturer (OUI) and the last three are unique to the device.
MAC addresses operate at Layer 2. Routers do not forward frames based on MAC addresses — they strip the Layer 2 header and use the Layer 3 IP address.
When SW1 receives a frame from PC1, it records PC1's MAC address against the port it arrived on in its MAC address table, so future frames destined for PC1 are sent only to that port.
MAC Address falls under the Network Fundamentals domain of the 200-301 exam. Understanding it in context with related terms like arp and broadcast-domain is essential for answering scenario-based questions correctly.