What is ARP's primary role in IP networking?

What is ARP's primary role in IP networking?

• A. Resolves IP to MAC addresses
• B. Routes packets between networks
• C. Provides reliable delivery
• D. Encrypts data

Answer: (A)

ARP maps IP addresses to MAC addresses on the local network. When a host wants to send an IP packet to another device on the same LAN, it needs the destination’s MAC to place the frame on the wire. If the MAC isn’t known, ARP broadcasts a request asking who owns that IP, and the owner replies with its MAC; the sending host caches this mapping for future use. This resolution only applies to devices on the same broadcast domain; routers handle forwarding across networks and use their own ARP entries for next-hop MACs. ARP doesn’t route packets, guarantee delivery, or provide encryption—those roles belong to routing, transport protocols like TCP, and cryptographic protocols, respectively.

ARP maps IP addresses to MAC addresses on the local network. When a host wants to send an IP packet to another device on the same LAN, it needs the destination’s MAC to place the frame on the wire. If the MAC isn’t known, ARP broadcasts a request asking who owns that IP, and the owner replies with its MAC; the sending host caches this mapping for future use. This resolution only applies to devices on the same broadcast domain; routers handle forwarding across networks and use their own ARP entries for next-hop MACs. ARP doesn’t route packets, guarantee delivery, or provide encryption—those roles belong to routing, transport protocols like TCP, and cryptographic protocols, respectively.