Cisco Enterprise Network Core Technologies (ENCOR) Practice Exam

The correct multicast address used for OSPFv3 is FF02::5. This link-local multicast address is specifically designated for OSPF (Open Shortest Path First) version 3, allowing OSPFv3 routers to communicate with each other within the same network segment without needing a specific unicast address.

OSPFv3 utilizes FF02::5 to send routing updates and various OSPF packets, ensuring efficient communication of routing information among OSPF routers. The use of this multicast address facilitates the discovery of adjacent routers and the sharing of routing tables, which are crucial for maintaining up-to-date network topology information.

The other multicast addresses mentioned serve different purposes. For instance, FF02::1 is the all-nodes multicast address and is used to send messages to all nodes on the local link. FF02::2 is the all-routers multicast address, which is utilized for routers to discover each other. Meanwhile, FF02::0 is not a valid multicast address for OSPF or any other specific networking protocol. Each of these addresses plays a role in IPv6 networking, but FF02::5 is the one explicitly designated for OSPFv3.