Dynamic vs. static routing

[rj.remien]

Is there any reason to use a routing protocol in place of static routing when there is only one route to a destination? In other words, should a routing protocol only be used when there is at least two routes to the same destination?

Thanks,

RJ

[thisisshanky · Accepted solution]

If its a stub network...Like the first scenario you mentioned, where there is only one route to a destination, Its better to use a static route (default). Still there is a disadvantage using this method.

Assume, A------B----C---X.

X is a network connected to C, and B and C are running routing protocol between each other, but A is using default static route to B.

Now B comes to know from C, when network X is down. But A will not know, anything abt network X. During this time, A will continue to send packtes to B, and B will drop them, because, there is no route to X. So the network changes were reflected dynamically through routing protocol in B, but not in A, because of the static route.

When you have two routes to a destination, still you can use both static and dynamic routing. So there is really speaking no recomendation that, you should be only using static routing for stub networks, and dynamic for two routes to same destination. Routing protocols are much better, than static routes, as they dynamically reflect network changes.

[rj.remien]

This is a very good descriptive example. Knowing when a network is down is good information. Thanks for you insight.

RJ