ARP is used to map IP addresses to which of the following?

ARP is used to map IP addresses to which of the following?

• A. MAC addresses
• B. DNS names
• C. Port numbers
• D. VLAN IDs

Answer: (A)

ARP translates an IP address into a MAC address on the local network. To deliver a data frame over Ethernet, the sending device must know both the IP destination and the destination’s hardware (MAC) address. ARP asks, “Who has this IP?” and the device that owns the IP replies with its MAC, allowing the sender to place the frame correctly on the local link and to cache this mapping for future use. DNS maps names to IP addresses, not MACs; port numbers identify processes at the transport layer, not devices on the local link; VLAN IDs tag frames for network segmentation, not address resolution. (In IPv6, Neighbor Discovery serves a similar role to ARP.)

ARP translates an IP address into a MAC address on the local network. To deliver a data frame over Ethernet, the sending device must know both the IP destination and the destination’s hardware (MAC) address. ARP asks, “Who has this IP?” and the device that owns the IP replies with its MAC, allowing the sender to place the frame correctly on the local link and to cache this mapping for future use. DNS maps names to IP addresses, not MACs; port numbers identify processes at the transport layer, not devices on the local link; VLAN IDs tag frames for network segmentation, not address resolution. (In IPv6, Neighbor Discovery serves a similar role to ARP.)