Troubleshooting OSPF Route Advertisement

This section discusses the problems related with OSPF route advertisement. OSPF is a link-state protocol. When it forms neighbor relationships, it exchanges the entire link-state database with its neighbor(s). If any database information is not shared with the neighbor, the link-state characteristics of OSPF will break.

The most common reasons for OSPF to not share the database information about a specific link are as follows:

The OSPF neighbor is not advertising routes.

The OSPF neighbor (ABR) is not advertising the summary route.

The OSPF neighbor is not advertising external routes.

The OSPF neighbor is not advertising the default route.

The sections that follow address these problems, the possible ...

Get Troubleshooting IP Routing Protocols now with O’Reilly online learning.

O’Reilly members experience live online training, plus books, videos, and digital content from 200+ publishers.