Editing Address Resolution Protocol (section)

{{Short description|Protocol used for discovering the network layer address associated with an internet layer address}}

{{IPstack}}

The '''Address Resolution Protocol''' ('''ARP''') is a [[communication protocol]] for discovering the [[link layer]] address, such as a [[MAC address]], associated with a [[internet layer]] address, typically an [[IPv4 address]]. The protocol, part of the [[Internet protocol suite]], was defined in 1982 by {{IETF RFC|826}}, which is [[Internet Standard]] STD 37.

ARP enables a host to send an IPv4 packet to another node in the local network by providing a protocol to get the MAC address associated with an IP address. The host broadcasts a request containing the node's IP address, and the node with that IP address replies with its MAC address.

ARP has been implemented with many combinations of network and data link layer technologies, such as [[IPv4]], [[Chaosnet]], [[DECnet]] and Xerox [[PARC Universal Packet]] (PUP) using [[IEEE 802]] standards, [[FDDI]], [[X.25]], [[Frame Relay]] and [[Asynchronous Transfer Mode]] (ATM).

In [[Internet Protocol Version 6]] (IPv6) networks, the functionality of ARP is provided by the [[Neighbor Discovery Protocol]] (NDP).