Need kind a VPN-solution

Hi,

We are a machine building company, and I am look for a way to remotely log-in to our machines. There are devices for that (we've used EWON for that).

However we do not install such a device in every of our machines, but what we do have in every automation, is a Windows PC.

Let me explain a little bit :

Our machines typically consist of a simple local network with fixed IP's, no router/DHCP. In that network you'll find a PLC, robot, camera, printer,... and also a Windows 10 PC. Via this "machine network", the devices can communicate and the equipment can work.

However we always put an 2nd NIC in the Windows PC, so that it has access to the company network. By using this 2nd NIC, the 'machine network' remains isolated and invisible from the company network. The Windows PC is typically used for logging, SQL-communication, and we also put teamviewer on it for remote assistance.

So this would be my question : If we want to edit the PLC-code on the PLC that is on the 'machine network', we need to put the PLC development software on the local machine-PC, so that it can connect to the PLC. Or we connect a laptop the the machine switch, so that it can see the PLC.

We were wondering if there is a way to have laptop in our office, dial in to a VPN-server on the local windows PC, and use this connection to connect to the machine network and the PLC.

So to use the machine-Pc as a gateway to connect remotely to any device on the local machine network.

The problem is that a regular (built-in PPTP, I know : old, don't use it) VPN server in Windows is blocked by the company firewall. So we can't just setup a VPN-server without going through the IT-department of the customer. We would like to avoid this, by using only outgoing connections (typically not blocked).

So I tried to use the Teamviewer VPN. Teamviewer has a built-in VPN-client and server, and is accessible behind a company's firewall.

So now I have a situation that I can connect my laptop from our company, to the VPN server on the machine PC at the customer. However my laptop gets an IP in the Teamviewer VPN-subnet, and cannot ping the machine network.

So I then need to bridge the VPN connection to the first physical NIC on the PC, right? But we are not succeeding in this.

Do you guys perhaps have a more elegant solution?

Thomas.