Which protocol is used to map an IP address to a MAC address by broadcasting (as per the material)?

Which protocol is used to map an IP address to a MAC address by broadcasting (as per the material)?

• A. IPv6 Neighbor Discovery
• B. DNS
• C. DHCP
• D. ARP

Answer: (D)

Mapping an IP address to a MAC address on a local network is done with ARP. When a host needs to send to an IPv4 address it hasn’t resolved yet, it broadcasts an ARP request asking who owns that IP and what their MAC is. Every device on the local network sees the request, and the one with the matching IP replies with its MAC address. The requester then caches this mapping and can frame subsequent packets directly to that MAC. This broadcasting behavior is a hallmark of ARP on IPv4 networks. In IPv6, a similar goal is achieved by Neighbor Discovery Protocol using ICMPv6 and multicast rather than broadcast. DNS translates domain names to IP addresses, not MAC addresses. DHCP is for obtaining IP configuration and related settings, not for mapping IPs to MACs.

Mapping an IP address to a MAC address on a local network is done with ARP. When a host needs to send to an IPv4 address it hasn’t resolved yet, it broadcasts an ARP request asking who owns that IP and what their MAC is. Every device on the local network sees the request, and the one with the matching IP replies with its MAC address. The requester then caches this mapping and can frame subsequent packets directly to that MAC. This broadcasting behavior is a hallmark of ARP on IPv4 networks.

In IPv6, a similar goal is achieved by Neighbor Discovery Protocol using ICMPv6 and multicast rather than broadcast. DNS translates domain names to IP addresses, not MAC addresses. DHCP is for obtaining IP configuration and related settings, not for mapping IPs to MACs.