Dynamic routing protocols help the network administrator manage the time-consuming and exacting process of configuring and maintaining static routes.
Imagine maintaining the static routing configurations for the seven routers in Figure 1.
What if the company grew and now had four regions and 28 routers to manage, as shown in Figure 2? What happens when a link goes down? How do you ensure that redundant paths are available?
Dynamic routing is the best choice for large networks like the one shown.