What does the Address Resolution Protocol (ARP) do?

The Address Resolution Protocol (ARP) is essential in computer networking, particularly in the context of the Internet Protocol (IP) suite. Its primary function is to translate network layer addresses, such as IP addresses, into data link layer addresses, commonly known as MAC (Media Access Control) addresses.

This translation is crucial for the operation of network communications. When a host wants to send a packet of data to another host on the same local area network, it must know the MAC address of the destination. IP addresses, which are used at the network layer, are logical addresses that are not sufficient on their own for data link layer communication, which relies on physical addresses (MAC). ARP enables devices to map the IP address to a MAC address, allowing for proper packet delivery on the local network.

Understanding ARP's role is fundamental because it highlights the layered architecture of networking. It underscores how different protocols interact to ensure successful communication, demonstrating the importance of address resolution in enabling devices to communicate effectively over IP networks.