Computer Networks Question:

The address resolution protocol (ARP) associates an IP address with the physical address. On a typical physical network (eg: LAN) each device on a link is identified by a physical or station address usually imprinted on the network interface card(NIC)Physical addresses can be changed easily, on the other hand IP addresses cannot be changed. ARP is used to find the physical address of the node when its internet address is known.
The reverse address resolution protocol(RARP) allows host to discover its internet address when it known only its physical address. RARP works much like ARP.
To obtain IP address the host first broadcasts an RARP request packet containing its MAC address on the network. All hosts on the network receive the packet, but only the server replier to the host by sending an RARP response packet containing the host's MAC and IP addresses. One limitation with RARP is that the server must be located on the same physical network as the host