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| 6.7 |  | Stub, Totally Stubby, and Not-So-Stubby Areas |
| 6.7.4 |  | 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 one plus any internal costs.

The only routes that will appear on the routing table for R4 are intra-area routes, the default route, and interarea routes. Intra-area routes are designated with an O in the routing table. Both the default and interarea routes are designated with an IA in the routing table. The default route will also be denoted with an asterisk.

Notice 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.

| Lab Activity e-Lab Activity: OSPF Stub Area Configuration Example In this lab, configure an OSPF stub area example.