[nsp] Cisco tunnel backup configuration

[Jay Fielding]

I am looking for some advise and help on a Cisco
backup configuration I'm setting up.  I am working on
a traditional frame-relay network and I'm looking for
a cheap backup solution.  I've already ordered a dsl
line because it was cheap and available for the remote
location.  I'm looking to use dsl and configure an
IPSEC GRE tunnel over the Internet back to the
headquarters.  I would like to have the router
immediately failover to the ipsec tunnel in the event
of a frame outage.

At headquarters, I have a VPN 3000 which I would like
to terminate the IPSEC GRE tunnel.  The company is
running EIGRP as the routing protocol and I thought
that I could configure the tunnel and let EIGRP handle
failover.  However, I can't find that the Altiega/VPN
3000 supports EIGRP. Without the VPN 3000 supporting
EIGRP, I'm not sure which would be the best way to
handle failover.  
 
I was looking into running OSPF at the remote location
and on the VPN concentrator.  Though, I would have to
run EIGRP and OSPF on the core router at headquarters.
 I have a cisco 2600 at the remote location and a
heavily used 3600 core router at headquarters.  Does
anyone have a similar configuration that wouldn't mind
providing some advise?

Thanks,
Jay