Which statement best describes how ARP resolves an IP address to a MAC address on a local area network?

Which statement best describes how ARP resolves an IP address to a MAC address on a local area network?

• A. ARP relies on the gateway to translate IP to MAC on the local segment.
• B. ARP uses DNS to resolve IP to MAC addresses.
• C. ARP assigns a MAC address to an IP via a centralized directory.
• D. ARP broadcasts an ARP request; the owner replies with its MAC address and the requester caches the mapping.

Answer: (D)

ARP maps an IPv4 address to a MAC address on the local network by broadcasting a request asking who has that IP, and the device that owns it replies with its MAC address while the requester caches that mapping for future use. This happens when a host needs to send a frame to another device on the same LAN and has no entry in its ARP cache; it sends a broadcast ARP request, every device sees it, the owner of the target IP responds with an ARP reply containing its MAC, and the requester stores the IP-to-MAC pairing for subsequent communications. DNS is about translating names to IPs, not IPs to MACs, so it isn’t involved in this local mapping. There is no centralized directory assigning MAC addresses to IPs in ARP, and ARP operates within the local broadcast domain rather than relying on gateways for the translation.

ARP maps an IPv4 address to a MAC address on the local network by broadcasting a request asking who has that IP, and the device that owns it replies with its MAC address while the requester caches that mapping for future use. This happens when a host needs to send a frame to another device on the same LAN and has no entry in its ARP cache; it sends a broadcast ARP request, every device sees it, the owner of the target IP responds with an ARP reply containing its MAC, and the requester stores the IP-to-MAC pairing for subsequent communications. DNS is about translating names to IPs, not IPs to MACs, so it isn’t involved in this local mapping. There is no centralized directory assigning MAC addresses to IPs in ARP, and ARP operates within the local broadcast domain rather than relying on gateways for the translation.