If two routers have an OSPF network type mismatch, what will occur?

When two routers experience an OSPF (Open Shortest Path First) network type mismatch, they can form an adjacency, but the specifics of their configurations prevent them from fully exchanging OSPF routing information.

Each OSPF network type defines how routers interact on various media (broadcast, non-broadcast, point-to-point, etc.). For instance, routers configured for broadcast networks expect to deal with multiple neighbors and handle multiple OSPF packets differently than those configured for point-to-point connections, which involve a direct link to one neighbor.

During the adjacency formation, the routers will successfully exchange "hello" packets, and an adjacency will be established. However, due to the mismatch in expected network behavior, they will not share or learn OSPF routes from each other. The routers will act as if they are neighbors, but the routing tables will remain static, leading to a lack of route learning between them. Thus, while they manage to establish a connection, the functionality of OSPF in routing information exchange is hindered by the network type discrepancy.