Title: Address Resolution Protocol (ARP)
ARP Protocol Overview
The Address Resolution Protocol (ARP), documented in RFC 826, translates a system's 32-bit IP address to its corresponding 48-bit Ethernet address.
ARP works by broadcasting a packet to all hosts attached to an Ethernet segment. The packet contains the ip address of the system with which the sender wishes to communicate. Only the host with this ip address answers the packet, sending its ethernet address in the response.
Hosts typically keep a cache of ARP responses (called the ARP table), based on the assumption that ip-to-hardware address mappings rarely change.