What are the states in OSPF when forming adjacencies?

In OSPF (Open Shortest Path First), the process of forming adjacencies involves several defined states that help routers communicate and establish relationships with one another. The correct answer identifies all the essential states — Down, Init, 2-Way, ExStart, Exchange, Loading, and Full — that occur during this adjacency formation.

Initially, when an OSPF router is trying to establish a neighbor relationship, it is in the Down state indicating that no communication has been established yet. As it sends hello packets, the router moves into the Init state, where it has received a hello packet from a neighbor but has not yet fully established bidirectional communication. When both routers recognize each other, they reach the 2-Way state; at this point, they can determine who will take the role of the designated router.

Following this, in the ExStart state, routers begin to negotiate the start of the database exchange process. The Exchange state follows, where the routers exchange their link-state advertisements (LSAs) to share routing information. After this, they enter the Loading state, where routers process the received LSAs and synchronize their databases. Finally, the Full state indicates that the adjacency is fully established, and both routers have synchronized routing information