Which OSPF state indicates the initialization phase of the neighbor relationship?

The Init state indicates the initialization phase of the neighbor relationship in the Open Shortest Path First (OSPF) protocol. In this state, a router has detected a neighbor but has not yet exchanged information or determined the full characteristics of that relationship. This is essentially the starting point where the router sends out Hello packets to its neighbors, and upon receiving a Hello packet from a neighbor, the router moves into the Init state.

During this phase, the router is waiting for the neighbor’s acknowledgement and is aware that a neighbor exists but hasn’t established any further communication. As the neighbor relationship progresses, the state will transition to Exstart, where routers begin to agree on the master/slave relationship before proceeding to share their link-state advertisements.

The other states mentioned, such as 2-way, Exstart, and Full, represent further steps in the neighbor discovery process and indicate established or progressing relationships rather than the initial phase itself. Thus, understanding the function and definition of the Init state is crucial in grasping how OSPF builds and maintains neighbor relationships.