Cisco Certified Network Associate (CCNA) Practice Exam

In the OSPF protocol, what is the correct order of states during the exchange protocol?

1. Loading state, full state, exstart state, exchange state

2. Exstart state, exchange state, loading state, full state

3. Exchange state, loading state, exstart state, full state

4. Full state, loading state, exchange state, exstart state

The correct answer is: Exstart state, exchange state, loading state, full state

In the OSPF (Open Shortest Path First) protocol, the states during the neighbor discovery and database synchronization process follow a specific sequence that is essential for establishing and maintaining OSPF neighbor relationships. The correct order starts with the exstart state, where the routers negotiate the parameters for establishing the adjacency. This is crucial, as both routers need to agree on the initial settings before proceeding to the next stage. Following this, the exchange state is where routers exchange hello packets containing their database description (DBD) information. This exchange is critical for sharing information about the OSPF database and ensuring both routers have a synchronized view of the network. Once the exchange of DBD packets is completed, the routers transition into the loading state. During this phase, routers request the full OSPF link-state advertisements (LSAs) from one another to ensure a complete and up-to-date view of the routing environment. This step is important for maintaining the integrity of the OSPF routing information. Finally, the full state is reached when the routers have fully exchanged all necessary routing information and established a complete OSPF adjacency. In this state, the routers can now exchange routing updates and share the overall routing topology efficiently. Thus, the correct order of