I need to set up a site to site vpn and on one end, the only internet connection option is ADSL. I have acquired a block of 6 IP addresses from the ISP, but Im unsure how to make the connection work considering that the DSL router seems to NAT even if in bridge mode, and the S2S vpn wont survive NAT. I have had no luck getting it to talk. What is the easiest option here? The ADSL modem has some limited static routing features but Im not sure if that will solve the problem. I have no management capability over the Cisco routers I just need to provide a connection that will allow the two routers set up that VPN tunnel.
Here is the goal:
Cisco 1800 router for site to site vpn endpoint
DSL modem (bridge mode?)
Cisco 1800 site to site vpn endpoint