Which IPv6 Neighbor Discovery function is used to locate routers on the local link?

• A. Router Solicitation
• B. Router Discovery
• C. Neighbor Solicitation
• D. Router Advertisement

Answer: (B)

When a host needs to learn which routers are on the local IPv6 link, it uses the Router Discovery process. The host sends a Router Solicitation message to the all-routers multicast address, and routers on the link respond with Router Advertisement messages. These advertisements announce available routers and provide important network information like the default gateway and prefix prefixes, enabling the host to configure itself for routing.

The other message types have different roles: a Router Solicitation is just the request sent by the host, a Router Advertisement is the router’s reply that carries routing information, and a Neighbor Solicitation is used for neighbor discovery and link-layer address resolution, not for discovering routers.