Reverse Address Resolution protocol

Reverse address resolution protocol does physical address to logical address mapping. A system with a local disk obtains its IP address from a configuration file when bootstrapped. But RARP is used by diskless systems such as an X terminal or a diskless workstation, to obtain their IP address when bootstrapped.
ARP and RARP both broadcast the request, and receive unicast reply. RARP request is broadcast with sender's hardware address, asking for sender's IP address.