OSPF is a link-state routing protocol. Such protocols are also referred to in the literature and technical documents as SPF-based or distributed database protocols. This section discusses the developments in link-state technologies that have influenced the evolution of the OSPF protocol.
What Is a Link-State Protocol?
OSPF is a link-state protocol. For example, you can think of a link as being an interface on the router. The state of the link is a description of that interface. This description would include the interface’s IP address and mask, and the type of network to which it is connected. This information is compiled for all the routers in your network into a link-state database, and the SPF algorithm is run against that data. ...