6.6 Multiarea OSPF Configuration and Verification  
  6.6.1 Using and configuring OSPF multiarea components  
The following paragraphs cover some of the multiarea OSPF capabilities and associated configurations in more detail. The student 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 two of its interfaces are configured to operate in different areas.

Configuring an ASBR
ASBRs are created when OSPF is configured to import, or redistribute, external routes into OSPF.

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

 

Web Links

Configuring OSPF

http://www.cisco.com/en/US/products/ sw/iosswrel/ps1828/products_configuration_ guide_chapter09186a00800ca56c.html