summary addresses and static routing

Unanswered Question
Nov 16th, 2007

Hi,I'm not sure if it possible to use summary addresses and static routing but here's the problem:-

We have a class b network 10.31.x.x and a gateway of and within that we want to have the class c's 10.31.1.x, 10.31.2.x each with their own g/way. I know that you can summarize with dynamic routing so that external routers only need to point to one to get to hosts on 10.31.1.x but was not sure if you could do this with static routes?



I have this problem too.
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Kevin Dorrell Fri, 11/16/2007 - 03:51

I'm not sure if this is your question, but ... yes you can have static routes that are subsets of each other. The more specific route wins.

For example, in your routing table you could have:

ip route Serial1/0

ip route Serial1/1

ip route Serial1/2

So, anything destined for any part of the class B would be send to Serial1/0 except destinations that fall into or, which would be routed to Serial1/1 or Serial 1/2 respectively.

I am using interface destinations for illustration - they could just as well be IP next-hop addresses.

You can even have the Class C routes from a dynamic routing protocol and the class B as a static if you want.

Does that answer your question?

Kevin Dorrell


paul_xedos Fri, 11/16/2007 - 06:13

Hi Kevin,

Thanks for the help but I was rather hoping to avoid adding specific route commands by using something similar to route summarisation found in dynamic routing protocols



Kevin Dorrell Fri, 11/16/2007 - 06:30

In that case, I don't think there is anything. But since the scope of a static route is only local, what advantage would there be to configuring it as a (hypothetical) summary on an interface rather than as a static route? I don't think I fully understand what you are trying to achieve.

Kevin Dorrell



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