OSPF Routing Protocol using Dijkastra Algorithm

What is OSPF?

The OSPF (Open Shortest Path First) protocol is one of a family of IP Routing protocols, and is an Interior Gateway Protocol (IGP) for the Internet, used to distribute IP routing information throughout a single Autonomous System (AS) in an IP network.

What is Dijkastra Algorithm?

Dijkstra's algorithm is an algorithm for finding the shortest paths between nodes in a graph, which may represent, for example, road networks

The topology table can easily be read to list off all of the networks and then one-by-one Dijkstra's algorithm calculates the best path to each of those destinations. So it's not like we run Dijkstra's algorithm and it answers all of the best paths. We run it each time we have to get to a unique destination network.

Dijkstra's Shortest Path First Algorithm comes up with based on its calculations. But it does those calculations based on the information it has in its topology table and we can't have information in the topology table unless we have neighbors. So it's an important relationship here between all these tables; that is very important for us to know because when it comes to troubleshooting, we have to be able to work our way around these tables to find out what's really going on if we don't have the routes we expect inside of that routing table.