Cisco Certified Network Associate (CCNA) Practice Exam

How can you display which OSPF interfaces are currently in a passive state?

1. #show ospf interface

2. #show ipv6 ospf neighbor

3. #show ipv6 ospf interface

4. #debug ipv6 ospf adj

The correct answer is: #show ospf interface

To display which OSPF interfaces are currently in a passive state, the command "show ospf interface" provides relevant information. This command outputs the status of all OSPF-enabled interfaces on the router, including details such as the interface type, OSPF state, and whether the interface is in a passive state or not. In OSPF, passive interfaces are those that do not actively participate in the OSPF routing process by sending or receiving OSPF Hello packets. This feature is often used to prevent OSPF from forming neighbors on interfaces where it is not desired, such as on interfaces connected to end hosts or where you don't want OSPF routing updates. The output from the command will clearly indicate which interfaces are passive, displaying the necessary information efficiently. The other command options do not serve this specific purpose. For instance, the command related to OSPF neighbors primarily focuses on neighbor relationships rather than interface states, while commands dealing with IPv6 OSPF interfaces or debugging will not provide a clear overview of which interfaces are passive. Only the command that directly lists OSPF interface statuses will give the necessary details about passive interfaces.