Question

Please discuss how a packet is routed from source node to its destination with the following algorithms:

1. Shortest path algorithm

2. Distance vector routing

Answer 1

2) Distance vector Routing

Lets understand the algorthm using an example

(due to the need of more drawings in have done it in a paper)

Initialization

At the start, each node can know only the distance between itself and its immediate neighbors,those directly connected to it.

The distance for any entry that is not a neighbor is marked as infinity(unreachable)

Sharing

The whole idea of distance vector routing is the sharing of information between neighbors.

Node A does not know about node E, node C does. Hence if  node C shares its routing table with A,node A can also know how to reach node E.

Nodes A and C, can improve their routing tables if they help each other

Updating

The receiving node needs to add the cost between itself and the sending node to each value in the second column.

Receiving node needs to add the name of the sending node to each row as the third column if the receiving node uses information from that row

Receiving node needs to compare each row of its old table with the corresponding row of the modified version
of the received table

1) Shortest path algorithm

The shortest path algorithm is also known as Dijkstra's algorithm,thsi algorithm works by finding shortest path between the node

Please see the flow chart to understand the algorithm

Analyse the below diagram to understand the process