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MAC Address

A unique hardware identifier assigned to network interfaces for local network communication.

NetworkingAlso called: "physical address", "hardware address"

Media Access Control (MAC) addresses are 48-bit values burned into network cards at manufacturing.

Format

  • 6 pairs of hexadecimal digits: 00:1A:2B:3C:4D:5E.
  • First 3 bytes identify the manufacturer (OUI).
  • Last 3 bytes are device-specific.

Uses

  • Layer 2 (Ethernet) addressing on local networks.
  • Device identification for access control (MAC filtering).
  • Network troubleshooting and asset inventory.
  • DHCP reservations for static IP assignment.

Security notes

  • MAC addresses can be spoofed easily.
  • Not suitable for authentication or security boundaries.
  • Visible to anyone on the local network.