Which protocol resolves IP addresses to MAC addresses?

• A. DNS
• B. ARP
• C. DHCP
• D. NAT

Answer: (B)

When a device on a local network needs to send a frame to another device, it must know the destination’s MAC address. IP addresses identify a device on a network, but to actually place a frame on the wire you need the MAC. Address Resolution Protocol performs this translation by broadcasting a request for the MAC associated with a given IP. The device that owns that IP replies with its MAC address, and the requester stores this mapping in its ARP table for future use. This resolution happens only on the local network segment; for communications beyond the local network, routing handles the next hop’s MAC address through the router’s interface.

DNS maps domain names to IP addresses, not to MACs. DHCP assigns IP configuration to hosts. NAT translates addresses as traffic moves between networks.