Which IPv6 component uses ICMPv6 for address resolution, neighbor reachability, and router discovery?

• A. NDP uses ARP
• B. NDP uses ICMPv6 messages (Neighbor Solicitation/Advertisement, Router Solicitation/Advertisement) for address resolution, neighbor reachability, and router discovery
• C. NDP is only for router advertisement
• D. NDP uses TCP handshakes for address resolution

Answer: (C)

In IPv6, address resolution, neighbor reachability, and router discovery are handled by the Neighbor Discovery Protocol. NDP uses ICMPv6 messages to perform these tasks: Neighbor Solicitation and Neighbor Advertisement for resolving a neighbor’s link-layer address and checking reachability, and Router Solicitation and Router Advertisement for discovering routers on the local link. This replaces ARP from IPv4, and it doesn’t rely on TCP handshakes. So the component described is the Neighbor Discovery Protocol (NDP), which operates via ICMPv6 for these functions.