I've read several other posts concerning this issue. However, I wanted to bring my specific structure to the table for discussion.
Main site has cisco 2911. We have several (<20) Software VPN users. In the near future I plan to set up site-to-site VPN's at several (<5) satellite locations. This will reduce or eliminate the number of software VPN users. Equipment there would be either PIX501 or ASA5505.
I need to get a fail over Internet connection at our main site. We currently have a cable modem. I want to put in DSL for backup. Ideally the 2911 would switch over after a failure of the main connection and all VPN users would not be interrupted. I'm not concerned about load sharing across ISP's, however, if a load sharing configuration helps produce the end result then I'm all for it.
So what is the best way to get this set up using our current equipment?