Which of the following is NOT an OSPF neighbor state?

The correct answer is "Complete." In Open Shortest Path First (OSPF), the states that a neighbor relationship can go through do not include a state called "Complete." The OSPF neighbor states that you will encounter include:

• Exstart: This is the state where routers determine which router will start the database exchange and which will be the master or slave in that exchange.

• Loading: In this state, routers are exchanging link-state updates to learn about the OSPF topology.

• Full: This indicates that the routers have successfully completed the database exchange, and they have synchronized their link-state databases.

These states are part of the neighbor establishment process that OSPF uses to establish and maintain neighbor relationships, ensuring that all routers in the same area have a consistent view of the network topology. The absence of the "Complete" state demonstrates a fundamental understanding of the OSPF process, as the term “Full” accurately describes the neighbors being fully synchronized.