Tried finding the answer but could not seem to do so, so here I go.
This is what I want to do (just a testing environment):
Users connect to a Win7 running a VPN service. The machine has a valid IP-address and I have tested the connection from the outside and authentication with the VPN. No problems.
This VPN PC has 2 NICs, one obviously to the Internet (direct) and the other one to a local network (192.168.0.x).
There is a second PC with 2 NICs. This PC has a working Proxy running on it (again test this).
This proxy PC has 1 NIC connected to the Internet (direct) and 1 NIC to the internal network (192.168.0.x).
The question is: How to I configure the VPN PC so all traffic coming in from users is redirected over the local network to the Proxy PC where the actual requests are send out and routed back over the internal network to the VPN server which routes it back to the users?
The only thing that I need to get working is piping all traffic from the VPN external NIC (say: 18.104.22.168) to the Proxy internal NIC (192.168.0.2).
You need a router to do that and win7 considers itself a end device. It will only terminate traffic it will not allow traffic to flow between nics that was not created by the machine itself.
Now there is something called RRAS Routing and Remote Access Services that runs in some windows SERVER platforms that can partially do this. There is some discussion saying parts of it work in a clinet like win7 but I have no direct knowledge.