Which protocol maps IP network addresses to MAC hardware addresses?

The Address Resolution Protocol (ARP) is specifically designed to map IP addresses (which are used at the network layer) to MAC (Media Access Control) addresses (which operate at the data link layer). When a device wants to communicate with another device on a local area network and knows only the IP address, it uses ARP to determine the MAC address that corresponds to that IP address.

When a device sends out a broadcast ARP request in the local network, any device that recognizes its own IP address will respond with its MAC address. This allows the initiating device to encapsulate the data packets with the correct MAC address for the destination, facilitating proper communication on the network.

Other protocols listed do not fulfill this role: the Internet Control Message Protocol (ICMP) is used for sending error messages and operational information; the Session Initiation Protocol (SIP) is primarily used for initiating, maintaining, and terminating real-time communication sessions; and the Transmission Control Protocol/Internet Protocol (TCP/IP) suite refers generally to the communication protocols that facilitate the transmission of data across networks but does not specifically perform the address mapping function that ARP does.