MAC Addresses and Local Networks

Name the local identifier

A MAC address is a hardware address on a network interface, written as six pairs of hex digits such as A4:83:E7:12:34:56. Switches and Wi-Fi access points use MACs to deliver frames on the local link.

Keep IP and MAC distinct

IP addresses work across networks. MAC addresses matter on the local segment. When your computer talks to a neighbor on the same LAN, it resolves the neighbor's IP to a MAC address (ARP on IPv4) and sends a frame to that MAC.

See why routers change the story

When traffic leaves your LAN, the frame is rebuilt hop by hop. Your packet keeps its IP destination, but each link uses the next device's MAC address.

Find a MAC when needed

On Windows, ipconfig /all shows physical addresses. On Linux, ip link lists interface MACs. Guest networks and privacy features may randomize Wi-Fi MACs.

# Linux
ip link show

# Windows (Command Prompt or PowerShell)
ipconfig /all