My problem is this:
My client has multiple servers, subnets, and routers in place. Everything works fine as it has been setup for years (dating back before my time). They are now looking at changing some of their setup and I seem to have hit a wall. They are using a software called NetMotion as their VPN. The setup is basically as follows.
Incoming internet is sent through a Prosafe VPN firewall which handles routing from the outside to the different servers(three to be exact) via their first NIC using a 192.168.x.x scheme. Each of the servers then have a second NIC that connects to their 10.24.x.x network. All server NICs are static IPs. On the primary server(srv1) in question, Hyper-V is running a Server 2012 R2 machine(we'll call it VM1) with two virtual NICs connecting to each network(192.168.x.x and 10.24.x.x). The NetMotion server software is running on VM1 and the client machine(currently being evaluated) connects through their client software(basically just a VPN client) via an external static IP that is routed through the Prosafe to the 192.168.x.x NIC on VM1. This is working fine through external networks and allows them to then connect to applications/databases running on the other two servers(srv2 and srv3).
I know that was a long explanation, but i'm trying to cover all bases here. Now comes the problem. What I haven't figured out is how to I allow access to the 10.24.x.x network through vm1. When physically on vm1, I can ping any clients on 10.24.x.x thanks to the second NIC. I can also browse network shares and use network printers. The problem I have is when I try to connect to those network shares and printers through the client machines when connected via VPN. Since the Prosafe controls the 192.168.x.x network, incoming connections can only route to NICs on the 192 network, thus the dual NIC configurations connecting to two networks. I'm sure there is some kind of routing to be done on vm1, but I have only limited routing experience.
Any help would be greatly appreciated. I'm sure I'm probably overlooking something simple that would get it working.
PS: I cannot change the two networks to be on one subnet(although that would be a much simpler solution in terms of everything working together). All of these systems are mission critical so taking the entire network down for a full reconfiguration is impossible. Thanks in advance.