5.3 Multiarea OSPF Configuration
5.3.1 Using and configuring OSPF multiarea components
The following paragraphs cover some of the multiarea OSPF capabilities and associated configurations in more detail. You will learn how to configure an ABR and how to configure route summarization.

Configuring an ABR
There are no special commands to make a router an ABR or an ASBR. The router becomes an ABR as soon as you configure two of its interfaces to operate in different areas, as shown in Figure .

Configuring an ASBR
ASBRs are created when you configure OSPF to import, or redistribute, external routes into OSPF, as shown in Figure .

Note that the ASBR configuration commands shown in Figure include the command redistribute rip. This command tells OSPF to import RIP routing information. A detailed discussion of route redistribution can be found in Chapter 7, Route Optimization.

Interactive Lab Activity (Flash, 383 kB)
  The purpose of this activity is to configure an Area Border Router in a multiarea OSPF environment.

SanJose1 and the Singapore routers have already been configured for OSPF routing. Your task is to configure SanJose3 to enable Inter-Area routing.