Which OSPF state follows the Exchange state?

In the OSPF (Open Shortest Path First) protocol, the state that follows the Exchange state is the Loading state. During the Exchange state, routers exchange Database Description (DBD) packets to share information about their link-state database. Once this exchange is complete, and the routers have established what they need to synchronize, they move into the Loading state.

In the Loading state, routers begin to request the specific link-state updates for any entries that they might not yet have in their databases. This is essential for ensuring that all routers ultimately have a complete and synchronized view of the network topology. Thus, the Loading state is crucial for efficient and accurate routing decisions.

Other states, such as Exstart and Negotiation, occur earlier in the process of establishing adjacency between OSPF routers. Exstart is the state where routers determine which one will be the master and adjust the sequence number for the exchange, while Negotiation is where routers exchange initial information about their databases to prepare for the DBD exchange.