I am building a DMVPN with static routing for my locations throughout the state using a 2821 as the hub and 877 as the spokes. These locations will primarily be talking to the hub...spoke to spoke communication won't be happening too often. Each location with have DHCP addressing from their ISP and most locations will be DSL (via Dialer interface).
I've got no problem running the DMVPN, and everything is working fine. What I want to do now is connect a modem via the AUX port of the 877 and allow each spoke to dial up to the internet and establish the tunnel via that when the primary connection is down.
I've tried many methods and done a lot of searching, but I am unable to get it working properly. Any suggestions or suggested reading?