Which of the following OSPF neighbor states is expected when the exchange of topology information is complete between two OSPF neighbors?

In Open Shortest Path First (OSPF), the correct state indicating that the exchange of topology information between two OSPF neighbors is complete is the Full state. When two routers establish a neighbor relationship, they progress through various states as they share their link-state information.

Once both routers have successfully exchanged and acknowledged their Link State Update (LSU) packets, and they have gathered the complete topology information from each other, they reach the Full state. In this state, both routers have a complete view of each other's link-state databases, which allows them to make informed routing decisions based on the updated topology.

To provide further context, the other states serve different purposes in the OSPF neighbor establishment process. The Init state indicates the initial stage where one router has received a Hello packet from a neighbor but has not yet completed the exchange of information. The Exstart state marks the beginning of the database description process, where routers negotiate who will start sending LSAs first. The 2-way state indicates that bi-directional communication has been confirmed, but this is not the final state where topology information is fully exchanged. Hence, the Full state is crucial as it signifies the completion of the exchange, ensuring both routers are synchronized and have a complete understanding of