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Load Balancing over two ADSL lines

Unanswered Question
Apr 27th, 2006
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I need to load balance traffic from one router over two ADSL lines but I only have control over the on-site router, not over the ISP router.

Is there a way of doing this...I've been reading trying to find some information regarding the subject but in all the papers they seem to think that you have to have control over the two routers (ISP and site) .....is it there a way of applying load balancing without having to contact the ISP and ask them to modify the config in their router???

so far my config looks like this....

ip address 88.x.x.x.255.255.0

ip access-group 150 in

ip access-group sdm_dialer1_out out

no ip redirects

no ip unreachables

no ip proxy-arp

ip nat outside

ip load-sharing per-packet

service-policy output policing

no ip route-cache

no ip mroute-cache

speed auto


hold-queue 224 in

I believe that the commands that I should apply at the interface level to load balancing are these two..

no ip route-cache

ip load-sharing per-packet

...combined with the "ip cef" command at the general level..........is this correct??

Finally........would "Multilink PPP" be an alternative????

Thank your for your help

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Overall Rating: 0 (0 ratings)
spremkumar Mon, 05/01/2006 - 21:56
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You can try configuring 2 equal cost default routes pointing towards the interfaces which are connected to the ISP end.

ip route dialer 0

ip route dialer 1

this will inturn take care of load balancing on the outbound direction..


vladrac-ccna Tue, 05/02/2006 - 09:10
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the configs you want to use will provide load-balancing per-packet, usually this is not needed (and sometimes not recommended , voip for instance dont tolerate jitter, as each packet will take a different path).

You can use cef to do load-balance per-destination, but this will only control how traffic goes out, not the way it comes in (this is why you need to control the ISP too, to have symmetrical paths).

and of course to load-balance you'll need 2 (or more) routes in the routing table.

So, maximum-path for routing protocols, or, as the other post recommends, 2 static routes pointing to the same IP.


if it does, I'd appreciate if you rate this post.



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