4.2 OSPF Operation
4.2.1 Steps of OSPF operation
OSPF routers progress through five distinct steps of operation:
  1. Establish router adjacencies.
  2. Elect a DR and BDR (if necessary).
  3. Discover routes.
  4. Select the appropriate routes to use.
  5. Maintain routing information.

The following sections describe each of these steps in detail.