Which protocol maps IP addresses to MAC addresses in IPv6?

Which protocol maps IP addresses to MAC addresses in IPv6?

• A. Neighbor Discovery using ICMPv6.
• B. DHCPv6 exclusively.
• C. ARP for IPv6.
• D. DNS mapping.

Answer: (A)

In IPv6, the process of turning an IP address into a data-link (MAC) address on the local link is handled by the Neighbor Discovery Protocol, which runs over ICMPv6. When a host needs to contact another IPv6 device on the same local network, it checks its neighbor cache. If the MAC isn’t known, it sends a Neighbor Solicitation to the target IPv6 address (delivered via the solicited-node multicast) and includes its own MAC in the ICMPv6 option. The target responds with a Neighbor Advertisement that carries its MAC address, allowing the initiator to fill its cache and send the IPv6 packet to that MAC. This mechanism also supports duplicate address detection and router discovery, all coordinated through ICMPv6 messages. DHCPv6 is used for configuring devices (like obtaining an IPv6 address and other information) but not for mapping IP to MAC on the local link. ARP is an IPv4 protocol and is not used in IPv6. DNS maps domain names to IP addresses, not MAC addresses.

In IPv6, the process of turning an IP address into a data-link (MAC) address on the local link is handled by the Neighbor Discovery Protocol, which runs over ICMPv6. When a host needs to contact another IPv6 device on the same local network, it checks its neighbor cache. If the MAC isn’t known, it sends a Neighbor Solicitation to the target IPv6 address (delivered via the solicited-node multicast) and includes its own MAC in the ICMPv6 option. The target responds with a Neighbor Advertisement that carries its MAC address, allowing the initiator to fill its cache and send the IPv6 packet to that MAC. This mechanism also supports duplicate address detection and router discovery, all coordinated through ICMPv6 messages.

DHCPv6 is used for configuring devices (like obtaining an IPv6 address and other information) but not for mapping IP to MAC on the local link. ARP is an IPv4 protocol and is not used in IPv6. DNS maps domain names to IP addresses, not MAC addresses.