ARP resolves IP addresses to which addresses?

• A. Subnet addresses
• B. Logical addresses
• C. MAC addresses
• D. Port numbers

Answer: (C)

ARP translates an IP address into the hardware (MAC) address used on the local network. IP addresses identify devices at the network layer, but to actually place a frame on the wire, the sender needs the destination’s MAC address. When a host wants to reach another IPv4 host, it checks its ARP cache for the IP. If the mapping isn’t known, it broadcasts an ARP request asking who owns that IP; the owner replies with its MAC, and communication proceeds with the Ethernet frame addressed to that MAC. Port numbers belong to the transport layer and aren’t resolved by ARP, and subnet or other logical addresses aren’t mapping targets ARP provides. So the correct mapping ARP provides is to MAC addresses.