Basic Process in OSPF
1. Each router discovers its neighbors on each interface. The list of
neighbors is kept in a neighbor table.
2. Each router uses a reliable protocol to exchange topology information
(LSAs – link state advertisements) with its neighbors.
3. Each router places the learned topology information in its topology
database.
4. Each router runs the SPF algorithm against its own topology database
to calculate the best routes to each subnet in the database.
5. Each router places the best route to each subnet in the IP routing table.