Reverse Address Resolution Protocol (RARP) is a Link layer networking protocol used by a host computer to obtain its IPv4 address given only its link-layer address (such as an Ethernet address). RARP is described in IETF publication RFC 903. It has been rendered obsolete by Bootstrap Protocol and the modern Dynamic Host Configuration Protocol, which both support a much greater feature set than RARP.

RARP requires one or more server hosts to maintain a database of mappings from Link Layer address to protocol address. MAC addresses needed to be individually configured on the servers by an administrator. RARP was limited, with respect to newer configuration protocols, to serving IP addresses only.

Reverse ARP differs from the Inverse Address Resolution Protocol (InARP), which is designed to locate the IP address associated with another station's MAC address. InARP is the complement of the Address Resolution Protocol used for the reverse lookup. RARP was only used for lookup of a host's own IP address.

See also

• Dynamic Host Configuration Protocol (DHCP)
• Bootstrap protocol (BOOTP)
• Address Resolution Protocol (ARP)
• Maintenance Operations Protocol (MOP)

External links

• RFC 903
• ftp://alycia.dementia.org/pub/net-tools/