How do routers behave during the OSPF Loading State?

During the OSPF Loading State, routers engage in the exchange of information critical for establishing a fully synchronized link-state database. This phase is characterized by routers acknowledging Database Description (DBD) packets that have been exchanged in the previous state and subsequently exchanging Link-State Advertisements (LSAs) that contain updates about the network topology.

When routers are in the Loading State, they are focused on ensuring that all neighboring routers have a consistent view of the network; this includes confirming receipt of LSAs and potentially receiving new information that may have emerged since the last update. The successful acknowledgment of DBD packets indicates that the routers are ready to share detailed link-state information to reach an accurate understanding of network routing paths.

The behavior of other processes, such as sending Hello packets, completing the neighbor discovery process, or entering a waiting state, pertains to different phases of the OSPF state machine. Sending Hello packets typically occurs in the interval where neighbor relationships are maintained, while the discovery process is completed before the Loading State begins. Entering a waiting state for LSAs is not an active engagement phase like the Loading State, but rather reflects a period of inaction versus the proactive information exchange central to the Loading State.