Arp definition by Webster's New World
Arp definition by American Heritage Dictionary
, Jean or Hans 1887-1966.
arp - Computer Definition
A protocol that translates between network addresses, such as between Ethernet and Internet Protocol (IP) addresses or between asynchronous transfer mode (ATM) and Ethernet addresses. See also ATM, Ethernet, and IP.
A technical term, ARP is a protocol that is used with TCP/IP to resolve addresses on the Link Layer of the Protocol Stack.
The address resolution protocol (see Figure 1-1) is used to find a hardware address for a given IP address. Computer names on the Internet are associated with IP addresses. To send a message to a computer via the local network (for example, through Ethernet or a wireless network), the hardware address must be known.
So, when a computer needs to transmit an IP packet to a computer in the same network segment, it broadcasts the destination IP address on the local Ethernet using the ARP protocol, where it is read by all attached computers. To achieve this, it fills out the fields of the protocol with its Ethernet address, its IP address, and the IP address of the destination, filling the destination IP Address with 1 and signaling that it is requesting the relevant Ethernet address. The computer owning the address then responds, and the IP packet can then be sent to that Ethernet address.
The ARP protocol is designed to serve in a more general fashion; it includes a Hardware Address Type and a Protocol Address Type that can be set according to the higher-level protocol’s needs.
Graham, R. Hacking Lexicon. [Online, 2001.] Robert Graham Website. http://www.linuxsecurity.com/resource_files/documentation/hacking-dict.html.
(Address Resolution Protocol) A TCP/IP protocol used to obtain a node's physical address. A client station broadcasts an ARP request onto the network with the IP address of the target node it wishes to communicate with, and the node with that address responds by sending back its physical address so that packets can be transmitted. ARP returns the layer 2 address for a layer 3 address. See ARP cache, ARP cache poisoning, RARP and TCP/IP abc's.