Reverse Address Resolution Protocol (RARP)
Reverse Address Resolution Protocol (RARP) fulfils the reverse function of Address Resolution Protocol (ARP). When provided with a 48-bit physical address RARP finds the Internet Protocol (IP) address. Again the ARP cache will be checked first, and if no match is found a broadcast will be sent over the Local Area Network (LAN) soliciting a response from the machine which possesses the given physical address.
RARP is also used in conjunction with the BOOT Prom (BOOTP) protocol used to boot diskless workstations.