best setup for 2 isp

[rgbatucan]

Hello,

We just acquired our 2nd ISP. I need some advice on what's best configuration or setup to our internet connection. Our goal is to maximize first all the bandwidth of 2nd ISP then when it's full, it goes to1st ISP. Please see network diagram below. Thanks.

[cisco_lad2004]

Hi,

You can use "backup load" comand where backup interafce is used as soon as a configured % is reached.

HTH

Samir

[Calin C.]

Depending on the scenario (you get a default route or the full routing table from ISP) there are multiple solutions.

Multihomed BGP I think is the best. You can also use EIGRP for it's unequal cost load balancing, but this is usually not a solution between customer and ISP. Simple static routing will also work (one default route prefered and another floating backup route)

I will stick with BGP explanation below.

Here you can find a scenario:

http://www.cisco.com/en/US/tech/tk365/technologies_configuration_example09186a00800945bf.shtml#conf4

Regarding the load-balancing, things will not work exactly how you expect. BGP support some unequal cost load balancing, but not on the way you expect to use on link until full then put the traffic on the other link.

http://blog.ine.com/2010/04/06/move-over-variance-bgp-proportional-load-balancing-is-here/

Another solution is to use one primary link and the other one as back if the bandwidth is different on the two ISP.

Also if the links have different bandwidth, you can prefer outboud some prefixes (less) on the less bandwith line and some prefixes (more) on the high bandwidth line with alternative backup over the other line. Inbound traffic is a little bit harder to control in this manner.

Let us know on which direction you want to go and we can help with configuration if needed.

Cheers,

Calin

[paolo bevilacqua]

It is not easy at all and will not be stable to work out at "overflow" configuration.

Recommend you will use regault traffic sharing instead.

Note that for, router must do NAT, not the ASA.

Unless you can get ASN and BGP from providers, that is in most cases unlikely.