Redudant ISP connections via DSL

[lucidus]

We're looking at setting up redudant/fault-tolerant/load-balanced conenctions to two different DSL providers. One options would be to have our firewall plug into a Cisco 2650, and have two ethernet interfaces on the 2650 that conenct to the two different DSL routers (running in bridge mode) from the two different ISP's. Then to set this all up with BGP. Will this work? Will BGP pass through the routers without any problems? Is this even the best way to do this? Another option would be a 2650 with two DSL WIC's that run to the two ISP's. Let me know what you think!
My other questions revolves around DNS issues. I'm assuming that DNS propogates out far enough that if the ISP holding our MX record goes down, that we'd still be able to get email through the other DSL provider. I appreciate any feedback!

 

[jeter]

WOW, to be honset with you I have not yet setup any DSL on a Cisco router. I have set them up on other routers. My first question to you would be why 2 differnet isp? Why not have one isp and get the maximum speed available for your location? Has far as the DNS you can, and I have done this use a different DNS for an other isp. The thing to remember
here is that its possible that they may be going out the same Redback at a Central office. J.Fisher CCNA
Jeter@LasVegas.com

 

[fynx]

If you are trying to install a resilient solution, may I suggest that the 2650 is a SPOF. (just my 2 pence worth

 

[lucidus]

We're looking at two different ISP's for redundancy. I know they may both use the same DSLAM, but there are other parts of the network they don't share and that would be helpful. Instead of doing DSL on the Cisco, like I mentioned, I could use the ISP provided DSL routers, but I'm not sure how well that would work with BGP.

 

[buraglio]

Are you running Servers? If you want to have redudant server access via your 2 DSL connections (i.e. access for prople from outside your network), remember that most ISPs won't accept BGP announcements of less than 8 class C's. If you are talking about iBGP just for outbound redundancy, then that may work, but it's probably overkill. I'm working on something similar myself with a customer of mine.

 

[lucidus]

Yes, we have two email servers and a VPN Concertrator. The main issue redudant conenctions came up is because we're putting more and more people on the VPN. If our internet connection goes down, then so do all our VPN connections.