Dijkstra Algorithm

Dijkstra Algorithm

1. Start with the local node (router) as the root of the tree.

2. Assign a cost of 0 to this node and make it the first permanent node.

3. Examine each neighbor of the node that was the last permanent node.

4. Assign a cumulative cost to each node and make it tentative.

5. Among the list of tentative nodes :

      a. Find the node with the smallest cost and make it permanent .

      b. If a node can be reached from more than one  route then select the route with the shortest cumulative cost.

6. Repeat steps 3 to 5 until every node becomes permanent.

Calculation of Routing Table from Shortest Path Tree

•       Each node uses the shortest path tree protocol to construct its routing  table.

•       The routing table shows the cost of reaching each node from the  root.