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load balancing question

Does anybody have a suggestion on what i should do:

I have a 2611 router with 3 network interfaces.

one goes to a leased line and the other a adsl router and the other the internal network.

I am wanting to use the adsl roter as a backup route or load balancing because the leased line is my main route out.

what would be the best way to do this?? i have been told to use ospf! if that is the case does anybody have a config that would do this???


Re: load balancing question

Presumably you have a default route pointing out the leased line interface. The easiest way to use the DSL interface as a backup is to configure a so-called 'floating static route' to point out the DSL interface. This is simply another default route, but with a higher administrative distance so that the leased line route is preferred unless the leased line is down. Search around for 'floating static route' and you should be able to find more information.

You can load share outbound traffic between the two links by not increasing the AD of the DSL route so that you end up with two equal default routes. You can then enable CEF if it isn't already and the router will automatically load balance outbound traffic on a per-flow basis. You'll probably need to NAT the source address of traffic that goes out the DSL interface so that the return traffic also comes through the DSL line. This isn't a concern with the leased line, as all inbound traffic to the IP block that you were assigned by the ISP will come in through that interface.

I'm sure someone here could provide specific commands if you post your current configuration, but I think your best bet would be to spend some time reading about this stuff so that you fully understand how it works when you implement it.

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