What problem does ARP solve?

What problem does ARP solve?

• A. Maps IP addresses to MAC addresses on a local network
• B. Resolves domain names to IP addresses
• C. Encrypts data in transit
• D. Determines shortest path routing

Answer: (A)

Translating IP addresses to MAC addresses on the local network. IP addresses identify devices logically across networks, but delivering a frame on a local Ethernet requires the hardware address (MAC). ARP provides a way for a host to discover the MAC address associated with a known IP by broadcasting a request on the local network; the device that owns that IP replies with its MAC, and the requester can cache this mapping for future use. This creates a bridge between the network layer and the data link layer so packets can be delivered on the local segment. Note that in IPv6 the same function is handled by Neighbor Discovery rather than ARP. The other mechanisms—DNS for domain-to-IP resolution, TLS/SSL for encryption in transit, and routing protocols for shortest-path decisions—address different problems.

Translating IP addresses to MAC addresses on the local network. IP addresses identify devices logically across networks, but delivering a frame on a local Ethernet requires the hardware address (MAC). ARP provides a way for a host to discover the MAC address associated with a known IP by broadcasting a request on the local network; the device that owns that IP replies with its MAC, and the requester can cache this mapping for future use. This creates a bridge between the network layer and the data link layer so packets can be delivered on the local segment. Note that in IPv6 the same function is handled by Neighbor Discovery rather than ARP. The other mechanisms—DNS for domain-to-IP resolution, TLS/SSL for encryption in transit, and routing protocols for shortest-path decisions—address different problems.