I have a situation where I require an IPSEC tunnel between two sites. Site 2 is a small branch office with basic (ADSL) connectivity and Site 1 is the "main" office with SDSL and ADSL for redundancy should the SDSL fail. From Site 1, all traffic bound for the 172.0.0.0 network will then be sent down another IPSEC tunnel to a supplier's Remote Server. See this page for the basic premise (this is a rough idea and things can be moved about etc...)
I am considering specifying Cisco ASA devices as the firewalls for both sites for all connections. Would it be possible to employ something like HSRC to provide a backup at Site 1 should the SDSL go down? I suppose the key aims here are that Site 2 can somehow failover to initiate a VPN to the ASA behind the ADSL at Site 1. I will have a 21 subnet mask on all internet connections so can play with Class C routing if need be...
If I'm barking up the wrong tree with HSRC, is there another way I can acheive this without massive expenditure on Barracuda routers et al?
Many Thanks.
With an ASA this is going to be tricky if you have 2 tunnels with the same destination network.
If you are prepared to setup some NATing for one of the endpoint networks you could use simple weighted static routes with your preferred tunnel having a lower metric.
This may be a little tricky to setup but you can avoid more complicated routing setups.