Software → Computer Networks
Address Resolution Protocol
A protocol used to map IP addresses to link-layer hardware addresses on a local network.
Motivation
ARP solves the problem of finding a device hardware address from an IP address on a local network.
Where it fits
ARP belongs to computer networks and is mostly relevant inside local area networks.
Mental model
ARP asks: who has this IP address? The device that owns it replies with its MAC address.
Common mistakes
- Using ARP as if it worked across the entire internet.
- Ignoring ARP spoofing as a local-network security risk.
Related concepts
ARP connects to IP, LAN, network interface card, and packet delivery.