Consider a computer network using the distance vector routing algorithm in its network layer. The Objective is to find the shortest cost path from router R to routers P and Q. Assume that R does not initially know the shortest routes to P and Q. R Assume that has three neighboring routers, X, Y Z R namely: and . During one iteration measures its distance as 3,2 , and 5 from its X, Y Z R neighbors and , respectively. Router getting routing vectors from its neighbors that indicates a distance of 7,6 and 5 from router X, Y Z P and to router , respectively. The routing vector also indicates that the distance to Q X, Y Z router from Routers and are 4, 6, 8 respectively. Which of the following statements is/are Ture with respect to the new routing table R at router after updation during this iteration. R P

A. The distance from to will be stored as 10 R Q

B. The distance from to will be stored as 7 R P

C. The next hop router for a packet from to Y is R Q

D. The next hop router for a packet from to Z is

Choose the correct answer from the options given below:

1. AB and C only
2. BA and C only
3. CC and D only
4. DB and D only

Pick an option to check yourself, or open the answer below.

Show answer & explanation

Correct answer: A. B and C only

Explanation

To P: via X 3 + 7 = 10, via Y 2 + 6 = 8, via Z 5 + 5 = 10, so 8 via Y. To Q: via X 3 + 4 = 7, via Y 2 + 6 = 8, via Z 5 + 8 = 13, so 7 via X. B and C are true.