Consider a general topology.

• The synchronous version of the distance – vector algorithm is used to compute the entries in the distance table.

• The nodes in the network are only aware of the costs of their immediate neighbors.

**The following procedure gives the maximum number of iterations required for the algorithm converges:**

• The node exchanges the distance tables with its neighbors in each iteration.

• For example, let node A represents the source node, and node B is a neighbor of node A, then all the neighbors of node B (which are one or two hops from node A) are aware of the shortest cost path to node A after the first iteration.

• Let d (be the diameter of the network) represents the length of the longest path without loops between any two nodes in the network.

• Using the above example, after *d-1* iterations, all nodes will know the shortest path cost of d or fewer hops to all other nodes.

• Any path with greater than d hops consists of loops which leads the result of the algorithm to converge in at most *d-1* iterations.

• When the Distance Vector algorithm runs as a result of a change in the cost of a link, then there is no priori bound on the number of iterations required until convergence and unless a bound on link costs are specified.

**Therefore, the distance vector algorithm converges in at most d -1 iterations.**

If you found this answer helpful, please upvote and share with other students in your network.