<networking, protocol> (ARP) A method for finding a host's Ethernet address from its Internet address. The sender broadcasts an ARP packet containing the Internet address of another host and waits for it (or some other host) to send back its Ethernet address. Each host maintains a cache of address translations to reduce delay and loading. ARP allows the Internet address to be independent of the Ethernet address but it only works if all hosts support it. ARP is defined in RFC 826. The alternative for hosts that do not do ARP is {constant mapping}. See also proxy ARP, reverse ARP. (1995-03-20)

The Address Resolution Protocol (ARP) is a communication protocol used for discovering the link layer address, such as a MAC address, associated with a given internet layer address, typically an IPv4 address. This mapping is a critical function in the Internet protocol suite.

Terminal Identifier – Address Resolution Protocol (TARP) is a protocol defined in Telcordia Technologies (formerly Bellcore) Generic Requirements document GR-253-CORE for SONET and used in OSS to resolve a TL1 TID to a CLNP address (NSAP) of a Network Element (NE). The protocol is used in a number of network devices.

<networking> Conversion of an Internet address into the corresponding physical address (Ethernet address). This is usually done using Address Resolution Protocol. The resolver is a library routine and a set of processes which converts hostnames into Internet addresses, though this process in not usually referred to as resolution. See DNS. (1996-04-09)

<networking> (AARP) Apple's system to allow AppleTalk protocol to work over networks other than LocalTalk, such as Ethernet or Token Ring. AppleTalk nodes announce their presence to the network so that other nodes can address messages to them. AARP maps between AppleTalk addresses and other schemes. It is actually a general address mapping protocol that can be used to map between addresses at any protocol level. [G. Sidhu, R. Andrews, and A. Oppenheimer, "Inside AppleTalk", Addison Wesley, 1990]. (2006-04-18)

IP address

Internet address

<networking> (Note lower case "i"). An IP address that uniquely identifies a node on an internet. [Jargon File] (1995-04-12)

<networking> (Internet address) The 32-bit number uniquely identifying a node on a network using Internet Protocol, as defined in STD 5, RFC 791. An IP address is normally displayed in dotted decimal notation, e.g. 128.121.4.5. The address can be split into a network number (or network address) and a host number unique to each host on the network and sometimes also a subnet address. The way the address is split depends on its "class", A, B or C (but see also CIDR). The class is determined by the high address bits: Class A - high bit 0, 7-bit network number, 24-bit host number. n1.a.a.a 0 <= n1 <= 127 Class B - high 2 bits 10, 14-bit network number, 16-bit host number. n1.n2.a.a 128 <= n1 <= 191 Class C - high 3 bits 110, 21-bit network number, 8-bit host number. n1.n2.n3.a 192 <= n1 <= 223 DNS translates a node's fully qualified domain name to an Internet address which ARP (or constant mapping) translates to an Ethernet address. [Jargon File] (2006-01-27)