Core Issue
OSPF is an interior gateway, link state routing protocol that exchanges link state updates with other routers in the network. The link state information exchanged with the neighbors is used to populate the topology database. All routers within an area have an identical database. The Area Border Router (ABR) has a topology database for multiple areas. The Shortest Path First (SPF) algorithm is run on the contents of the link state database to build the routing table.
Resolution
The contents of the OSPF database can be viewed by issuing the show ip ospf database in EXEC mode. To understand the OSPF database, refer to OSPF Database Explanation Guide.
