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New Member

1 router, 2 wan links... balancing?

Good day everyone and sorry (again) for this noob question.

This company cannot have a dsl connection so the provider suggested 2 isdn physical lines. Not going in details for this offer.

Now, what i'd like to do is to use a a 2600 series router with two ISDN WICs.

Do anyone have any advice on how to balance the traffic properly?

Thanks a lot


Re: 1 router, 2 wan links... balancing?

Hi Simon,

If you want you can have one link as backup but if you want load balancing you can use policy base routing using route maps and do the load balancing. I mean it is not a exact load balancing like 50% traffic from one link and rest from other but yes using route maps you can define that certain ip traffic for certain ports route through one link and rest all from other.

I think PBR using route maps is the best option in your case.



New Member

Re: 1 router, 2 wan links... balancing?

Thanks Ankur, very useful.

Unluckly, most of the user will be using just http, so discriminating using destination port would be somehow useless.

I was wondering (and now I will discover) if it's possible to use route-maps to split the clients pool in the two wan links, so that the first... say, 5 use one link and the rest use the other.

The ideal would be splitting the real connections pool. Let's see.

Thank you

Hall of Fame Super Silver

Re: 1 router, 2 wan links... balancing?


While the suggestion from Ankur about policy based routing is one interesting possibility, I think that there are some other possibilities that you might consider.

- since the ISDN will almost certainly be configured using encapsulation PPP, you might consider the possibility of using the multilink capability. Multilink takes several separate physical links and binds them into one logical link. Multilink does a very effective job of spreading the data over the physical links so you get very good load balancing.

- another possibility is to configure each of the ISDN channels separately. Give each one its own IP address. And configure 4 default routes (one default route per ISDN channel). This would present 4 independent paths to the outside. And the IOS would default to doing per destination load balancing. So this would not matter if the users are using mostly http. If they are going to different destination addresses you will get traffic over the various physical links.



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