Inverse Address Resolution Protocol InARP <networking, protocol> (InARP) Additions to {ARP} typically used for {Frame Relay}. [Any other examples of its use?] {Frame Relay} stations {route} {frames} of a higher level protocol between {LANs}, across a {Permanent Virtual Circuit}. These stations are identified by their {Data Link Control Identifier} (DLCI), equivalent to an {Ethernet address} in a {LAN} itself. InARP allows a station to determine a protocol address (e.g. {IP address}) from a DLCI. This is useful if a new {virtual circuit} becomes available. Signalling messages announce its DLCI, but without the corresponding protocol address it is unusable: no {frames} can be {routed} to it. {Reverse ARP} (RARP) performs a similar task on an {Ethernet} {LAN}, however RARP answers the question "What is my IP Address?" whereas InARP answers the question "What is your protocol address?". See {RFC 2390}. (2000-01-15)