====== INARP ======

===== Inverse Address Resolution Protocol =====

The Inverse Address Resolution Protocol, also known as "Inverse ARP" or "InARP", is a protocol used for obtaining Layer 3 addresses (e.g., IP addresses) of other nodes from Layer 2 addresses (e.g. the DLCI in Frame Relay networks). It is primarily used in Frame Relay and ATM networks, where Layer 2 addresses of virtual circuits are sometimes obtained from Layer 2 signaling, and the corresponding Layer 3 addresses must be available before these virtual circuits can be used.

[[:glossaire:ARP]] translates Layer 3 addresses to Layer 2 addresses, therefore InARP can be viewed as its inverse. In addition, InARP is actually implemented as an extension to ARP. The packet formats are the same; only the operation code and the certain field values differ.

Reverse ARP (RARP), like InARP, also translates Layer 2 addresses to Layer 3 addresses. However, RARP is used to obtain the Layer 3 address of the requesting station itself, while in InARP the requesting station is querying the Layer 3 address of another node. RARP was obsoleted by BOOTP which itself has been superseded by the Dynamic Host Configuration Protocol (DHCP).

Voir:
  * [[:glossaire:ARP]], [[:glossaire:RARP]], [[:glossaire:IP]]
  * Wikipedia [[http://fr.wikipedia.org/wiki/Address_Resolution_Protocol|FR]] et [[http://en.wikipedia.org/wiki/Address_Resolution_Protocol|EN]]