CCNP Routing and Switching ROUTE 300-101 Official Cert Guide

Domain-Wide Defaults Using the default-information originate Command

The OSPF subcommand default-information originate tells OSPF to create a Type 5 LSA (used for external routes) for a default route—0.0.0.0/0—and flood it like any other Type 5 LSA. In other words, it tells the router to create and flood information about a default route throughout the OSPF domain.

For example, consider a typical single multihomed Internet design, as shown in Figure 9-7. In this case, the enterprise has two Internet-connected routers, and the engineer wants to use default routing inside the enterprise to cause all the enterprise routers to send packets toward either ASBR1 or ASBR2.

Figure 9-7 Single Multihomed Internet Design Using Default Routes

The default-information ...