I have two broadband networks; one is cable modem connected (call it net1), the other is DSL (net2). Both broadband connections are DHCP assigned, however the net2 is assigned a private non-routable IP (ISP uses 172.x.x.x addressing). Net1 utilizes dyndns.org to resolve to the current IP. At each network a Linksys BEFSX41 sits behind the modem. The local and remote secure nets on the VPN setups on both ends are configured for each other's full subnet. Behind net1's router is a 10.0.1.0/24 network, and behind net2's router is a 10.0.2.0/24 network. I can establish the VPN by letting net2's router initiate the connection to the dyndns.org FQDN. Once connected however, I cannot ping 10.0.2.1 from a 10.0.1.x address, and vice versa. Also tried http connections with no luck.
In the past, we used PPTP tunnels through the routers to create a server to server tunnel with no problem, but this needs to be hardware based now with no software based connections.