Functions of OSI and TCP/IP Layers Q.45
Consider a network with five nodes, N1 to N5, as
shown as below.
Consider a network with 6 routers R1 to R6 connected
with links having weights as shown in the following
diagram.
The network uses a Distance Vector Routing protocol. Once the routes have been stabilized, the distance vectors at different nodes are as follows.
N1 : (0, 1, 7, 8, 4)
N2 : (1, 0, 6, 7, 3)
N3 : (7, 6, 0, 2, 6)
N4 : (8, 7, 2, 0, 4)
N5 : (4, 3, 6, 4, 0)
Each distance vector is the distance of the best known path at that instance to nodes, N1 to N5, where the distance to itself is 0. Also, all links are symmetric and the cost is identical in both directions. In each round, all nodes exchange their distance vectors with their respective neighbors. Then all nodes update their distance vectors. In between two rounds, any change in cost of a link will cause the two incident nodes to change only that entry in their distance vectors.
- Option : C
- Explanation : In the next round, N3 will receive distance from N2 to N1 as infinite. It will receive distance from N4 to N1 as 8. So it will update distance to N1 as 8 + 2 = 10.
