Glossary: Networking Basics

ARP

Also written: Address Resolution Protocol, ARP request, ARP reply, who-has, is-at

Address Resolution Protocol: how a host finds the MAC address that belongs to an IP address on its own LAN. It broadcasts a request ("who has 192.168.20.1?"), and only the owner of that address replies ("is-at 02:00:00:00:00:01").