ITPEC FE Subject A April 2025 Question 25

Which of the following is an appropriate explanation regarding Address Resolution Protocol (ARP)?

a)It converts MAC addresses into IP addresses.b)It resolves domain names into its IP addresses.c)It resolves IP addresses into the corresponding MAC addresses.d)It translates IPv4 addresses into IPv6 addresses.

Explanation

IP address to MAC address — ARP finds the hardware address that belongs to a known IP address on the local network.

To send a frame, a host needs the MAC address of the target, or of the default gateway when the target is on another network. ARP broadcasts a request, "who has this IP address?", and the owner of that address replies with its MAC address, which the sender then caches.

Answer (c)

Why not others:

•(a) — MAC to IP is the reverse direction, done by RARP (a legacy protocol) and today by DHCP
•(b) — resolving domain names into IP addresses is DNS
•(d) — translating between IPv4 and IPv6 is done by transition mechanisms such as NAT64, not by ARP

Key rule: ARP maps IP → MAC within one link; DNS maps names → IP across the internet.

Networks · AI-written, may contain errors

Previous Next

Practice this exam

This question comes from an official ITPEC past paper. ITPEC Practice is an independent study tool and is not affiliated with ITPEC. See the official FE past-paper collection or Report an issue.