In IPv4 networks, what does ARP do?

In IPv4 networks, what does ARP do?

• A. Translates IPv4 addresses to MAC addresses by broadcasting a request and receiving a reply with the MAC
• B. Verifies route paths between networks
• C. Encrypts data over VPN
• D. Maps IP addresses to DNS names

Answer: (A)

ARP’s job is to translate IPv4 addresses into MAC addresses on a local network. When a device wants to send a packet to another host on the same LAN, it first checks its ARP cache for the destination IP. If there’s no entry, it broadcasts an ARP request asking who has that IP, and the device that owns it replies with its MAC address. With that MAC, the sender can place the frame on the wire and reach the destination. That mapping is stored temporarily in the ARP table to speed up subsequent traffic. The other options describe different technologies: routing verifies paths between networks, VPNs encrypt data, and DNS maps domain names to IP addresses—not MACs. ARP is specifically about resolving IP addresses to MAC addresses on the local network.

ARP’s job is to translate IPv4 addresses into MAC addresses on a local network. When a device wants to send a packet to another host on the same LAN, it first checks its ARP cache for the destination IP. If there’s no entry, it broadcasts an ARP request asking who has that IP, and the device that owns it replies with its MAC address. With that MAC, the sender can place the frame on the wire and reach the destination. That mapping is stored temporarily in the ARP table to speed up subsequent traffic.

The other options describe different technologies: routing verifies paths between networks, VPNs encrypt data, and DNS maps domain names to IP addresses—not MACs. ARP is specifically about resolving IP addresses to MAC addresses on the local network.