Cisco Certified Network Associate (CCNA) Practice Exam

What indicates a successful OSPF neigborship between two routers?

1. Interfaces must be in active mode

2. Router IDs must be identical

3. Hello and Dead timers do not need to match

4. Network Types can differ

The correct answer is: Interfaces must be in active mode

A successful OSPF (Open Shortest Path First) neighborship between two routers is primarily indicated when certain conditions related to interface configuration and parameters are met. For OSPF to establish a neighborship, the routers must successfully exchange OSPF Hello packets. The interfaces must be in an active state, meaning they are up and operational. This ensures that both routers can send and receive the necessary OSPF packets. If either interface is down or not functioning correctly, the routers will not be able to establish a neighborship. The other conditions related to OSPF, such as router IDs needing to be identical, are not required for a successful neighborship. In fact, router IDs must be unique for each router within an OSPF area. Additionally, Hello and Dead timers must match between routers to form a neighborship, while network types can sometimes differ, though it might limit certain types of adjacencies. Thus, the key indicator of a successful OSPF neighborship is that the interfaces involved must be active and properly configured to support OSPF.