How are OSPF neighbors determined?

In OSPF (Open Shortest Path First), the formation of neighbor relationships is essential for the exchange of routing information. Neighbors are determined by several factors, primarily the matching of certain parameters that are crucial for the OSPF protocol to establish communication between routers.

One of the key parameters that OSPF checks are the Hello and Dead intervals, which dictate how frequently OSPF sends Hello packets and how long it will wait to consider a neighbor down, respectively. Both routers on a link must have the same Hello and Dead interval settings to recognize each other as neighbors. If these intervals do not match, the routers will not form an OSPF neighbor relationship.

Additionally, the area ID is another critical factor. OSPF operates within a subdivided network structure called areas. Each OSPF router must belong to the same area for neighboring relationships to be formed. When routers in the same area advertise their OSPF capabilities, they can successfully establish neighbor adjacencies.

Other options do not encompass the full range of criteria or mechanisms involved in neighbor establishment. For example, while network type is important in some scenarios, it alone does not determine neighbor formation without also considering Hello/Dead intervals and area ID. Manual configuration may influence routes