5.4 Stub and Totally Stubby Areas
5.4.4 OSPF stub area configuration example
In the figure, Area 2 is configured as a stub area. No routes from the external autonomous system will be forwarded into the stub.

The last line in each configuration, area 2 stub, defines the stub area. The area stub default-cost has not been configured on R3, so this router will advertise 0.0.0.0 (the default route) with a default cost metric of 1 plus any internal costs.

The only routes that will appear in R4's routing table are intra-area routes (designated with an O in the routing table), the default route, and interarea routes (both designated with an IA in the routing table; the default route will also be denoted with an asterisk).

Note that each router in the stub must be configured with the area stub command. The area stub command determines whether the routers in the stub become neighbors. This command must be included on all routers in the stub area if they are to exchange routing information.