What are common reasons why an OSPF neighbor relationship cannot change to full state

Common causes of this problems are:

The OSPF network is a non-broadcast multiple access (NBMA) network, and no neighbor is configured.
The interval at which the OSPF neighbor sends Hello packets is longer than the aging time of the neighbor relationship.
In a stub area or not-so-stubby area (NSSA) area, some devices are not configured as stub routers or NSSA routers.
The configuration of OSPF verification is incorrect.
The OSPF router IDs on two ends of the OSPF link are different.
The network types on two ends of the OSPF link are different.
The MTU values on two ends of the OSPF link are different.
OSPF is not enabled on the local or remote device.
The area numbers on two ends of the OSPF link are different.

Scroll to top