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.