a. b. Figure 5.7 Changes in link cost 11. Consider Figure 5.7. Suppose there is another router w, connected to router y and z. The costs of all links are given as follows: c(x,y)=4,c(x,z)=50, c(y,w)=1,c(z,w)=1,c(y,z)=3. Suppose that poisoned reverse is used in the distance-vector routing algorithm. a. When the distance vector routing is stabilized, router w,y, and z inform their distances to x to each other. What distance values do they tell each other? b. Now suppose that the link cost between x and y increases to 60 . Will there be a count-to-infinity problem even if poisoned reverse is used? Why or why not? If there is a count-to-infinity problem, then how many iterations are needed for the distance-vector routing to reach a stable state again? Justify your answer. c. How do you modify c(y,z) such that there is no count-to-infinity problem at all if c(y,x) changes from 4 to 60