During which OSPF state do routers exchange Database Description (DBD) packets?

The correct state during which routers exchange Database Description (DBD) packets in OSPF is the Exchange state. In this phase, OSPF routers that have established a connection move to share their link-state information. The Exchange state allows routers to send and receive DBD packets, which summarize the contents of their link-state databases.

This packet exchange is crucial because it helps minimize the amount of data that needs to be transferred initially, as the DBD packets only contain headers that provide information about the LSA (Link State Advertisement) entries available in each router's database. Each router can then determine if it requires any additional information to synchronize its link-state database with its neighbor.

In the context of OSPF operational steps, this state follows the Init state, where routers first send Hello packets to discover neighbors, and precedes the Loaded state, where the databases of the routers are fully synchronized. Thus, understanding the Exchange state and the significance of DBD packets is essential for grasping how OSPF efficiently routes information in a network.