Consider a network system having 4 routers P,Q,R AND S as shownbelow.initially, the routersise Distance vector routing and use number of hops as distance metric.
Initially, link p-q was down and all other routers agree p is unreachable.thr link p-q comes back up. Let x be the number of exchanges needed by routers P to stabilize its table having distance to all the other routers.assume the routers all exchanges all the messages at the same instant.After reaching to stable state the link goes down again.let y be the number of exchanges need for all the routers to conclude that P is unreachable..what is the value of x and y??
I think x should be 2 or 3 and y should be 2 or 3.
When p-Q links comes back.first exchange Q and R sends information amd R updates path to P. Second exhange S and R sends information and S also updates path to P.
And same thing will done when link P-Q goes down.
There will not be "count to infinity" problem as all routers are sending the information at the same instant.
How to solve this ques?