Mention the difference between ARP, RARP and ICMP protocols

ARP stands for Address Resolution Protocol. It is a protocol used for mapping an IP address into a physical machine address identified in the local network. The physical machine address is also known as the MAC address or Media Access Control. In IPv4, the most common level of IP address in use nowadays is 32 bits long.

While in an Ethernet local area network, the address for every attached device is 48 bits long. The ARP cache, which is the usual name they call for the table used by ARP, is used to keep the association among every MAC address and its matching IP address. RARP stands for Reverse Address Resolution Protocol.

It is the protocol used by a physical machine connected to a local area network to request to learn its IP address. RARP is available for token ring local area networks, Fiber Distributed-Data Interface, and Ethernet.