In OSPF, what role do DBD packets play during the ExStart state?

In OSPF, during the ExStart state of the neighbor adjacency establishment process, DBD (Database Description) packets play a critical role in exchanging database summaries. This state is where routers that are initializing their adjacency will start to negotiate the master/slave relationship to determine which router will send and which will receive DBD packets.

The DBD packets contain a summary of the Link State Advertisements (LSAs) that exist in the routing databases of the routers. By comparing these summaries, the routers can identify which LSAs they already have and which ones need to be requested for synchronization. This is crucial for ensuring that both routers have the same routing information so they can make informed forwarding decisions.

The other options do not accurately represent the role of DBD packets in the ExStart state. For instance, neighbor discovery occurs earlier in the OSPF process, while routing information updates are handled through different packet types once the adjacency has been established. Router priority is relevant in the context of election processes for designated routers but does not pertain to the function of DBD packets during the ExStart state.