Inverse Address Resolution Protocol
<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.