OSPF Areas

• OSPF allows a autonomous system’s network to be divided into routing areas

• An area contains one or more subnets

• Each area runs the OSPF algorithm independently of the others

• There must be a “backbone” area

• All areas must connect to the backbone

• “Stub” areas have only one exit point

• Some people recommend no more than 50 routers per area – having a larger area is possible but complex