Consider the network with the topology shown in Figure $1.$

$($a$)$ Run an example of RIP on this network to find the minimum paths between all nodes. Show the routing

tables at each time step.

A

B C

D

$2$

$3$

$1$

$6$

Figure $1$: A small graph for an example of RIP.

$($b$)$ Now the link between A and C fails, resulting in a cost of $\backslash$infty for both directions of transmission. B and

C immediately detect the link failure and update their own routing tables using the information they already

have from their one$-$hop neighbors. Write down the routing tables for four iterations after the link failure. You

need to only show the routing tables that change. What is happening to the paths to A$?$

$($c$)$ Propose a solution to the problem found in $($b$).$

$1$