Load-balancing over multiple ADSL links towards Internet

[cminard]

Hi

I have a 1801 router(1 ETH, 1 ADSL, 1 Switching module) and 2 access to the Internet via 2 different providers (one access directly ADSL and the other one Ethernet through the provider ADSL box).

I'd like to use the 2 access to load-balance the traffic to the Internet and to backup shoud one of the 2 links fails.

I have to NAT to different @ depending of the link I use.

Can anybody help me with the features and commands to use, please ?

Thanks

Caroline

[izackvail · Accepted solution]

Hi Caroline, if you create 2 static routes the router will load balance across them. Just point one at the Ethernet interface and point one at the ADSL interface.

Example:

ip route 0.0.0.0 0.0.0.0 eth0

ip route 0.0.0.0 0.0.0.0 atm0

However, keep in mind that this will load balance equally. This will also allow the router the redundency you want if one of the links fails.

You might find this article helpful

http://blog.ioshints.info/2007/02/unequal-load-split-with-static-routes.html

[cminard]

Hi

Thank you very much for your help. Your tips are really useful.

My problem is for the VPN traffic that must go out through the same interface but also have the backup, in case of failure of that interface. I read in your document that CEF should solve the problem, shoud'nt it ?

I have also found something interesting on cisco.com with SLA configuration. I think that with all that, I should have the complete configuration of what I want to do.

http://www.cisco.com/en/US/tech/tk648/tk361/technologies_configuration_example09186a00808d2b72.shtml

Thanks again

Caroline