Full Form of ARP:
Address Resolution Protocol
ARP Full Form is Address Resolution Protocol. ARP is a telecommunication network protocol used for converting an IP address to a physical address like Media Access Control address (shortly MAC Address). RFC 826 defined ARP in the year 1982 and it is being implemented with many networks and data link technologies like Chaosnet, Internet Protocol version 4, PARC Universal Packet, DECnet, etc.
ARP is mainly used in the sector of telecommunication. It is used to successfully convert an IP address to a physical address like an Ethernet address. These physical addresses are commonly known as DLC (Data Link Control) addresses. First defined in 1982, ARP is an integral and important part of the interface between OSI network and OSI link layer. It operates below the network link layer.
Its function helps the users in a various way. If a user or host initiates the ARP request on TCP/IP network, the broadcasted request helps the user to obtain information about the physical address of the connection which is actually provided by the IP address holder. It is mainly used in IPV4 networking addresses. In IPV 6, NDP (Neighbor Discovery Protocol) functions in the place of ARP.
RARP (Reverse ARP) is used when a user wants to gain information about his IP address. In such cases, physical addresses are broadcasted by the host and the server replies with information including respective IP addresses. So this protocol is very efficient in both cases. In order to create and maintain a continuous correlation between MAC addresses and corresponding IP addresses, and to ensure efficient address conversion in both ways, ARP cache is used.