Cisco Certified Network Associate (CCNA) Practice Exam

To confirm that interfaces are in the same subnet in an OSPFv3 network, which command should you use?

1. #show ipv6 route

2. #show ipv6 interface

3. #show ipv6 neighbors

4. #show ipv6 ospf link

The correct answer is: #show ipv6 interface

The command that confirms whether interfaces are in the same subnet in an OSPFv3 network is the one that shows detailed information about the IPv6 configuration on the interfaces. This command provides output that includes the IPv6 address assigned to each interface along with the associated prefix length and other settings. By examining this information, you can determine if the interfaces under consideration share the same subnet prefix. In the context of OSPFv3, having interfaces in the same subnet is essential for forming OSPF adjacencies and allowing them to properly exchange routing information. If the interfaces do not share the same subnet, they will not be able to establish a successful OSPF neighbor relationship. The other commands serve different purposes. The command that shows the IPv6 routing table provides insight into the routes known to the router, while the command for viewing IPv6 neighbors is used for discovering directly connected devices on the same link. The command specifically related to OSPF link information would provide details about the OSPF state and configurations, but it does not directly confirm subnet information like the chosen command does. Therefore, checking the interface configuration is the most direct way to verify that interfaces are in the same subnet for OSPFv3 operation.