Question

Two routers, R1 and R2, are connected over an Ethernet link and both have OSPFv2 enabled on the connecting interfaces in area 0. The interfaces are in the same subnet, router IDs are unique, and MTU matches. However, the neighbor adjacency never forms. On R1 the interface shows 'Hello 10, Dead 40' and on R2 it shows 'Hello 30, Dead 120'. What is preventing the adjacency?

Accepted Answer

The Hello and Dead timers do not match between the two interfaces.

Answer

The two routers have different OSPF process IDs configured.

Answer

One interface is configured as passive, suppressing Hello packets.

Answer

The routers are using different OSPF network types on the link.