My problem is that my work LAN is using mobile internet provider to access internet, so none of the PC's neither our router is accessible from Internet. I'd love to have possibility to connect to Remote Desktop of any PC in our local LAN, for remote work. That's more or less our network topology:
So before we changed offices we had routings configured on our router so we could use RDPS on PC1-PC3 from Employee's notebooks, because our ISP didn't block inbound traffic.
Now our new ISP blocks inbound traffic, so we are no longer able to connect to our router and further into the network.
The solution I thought of, is to place OpenVPN server on Our VPS (which is accessible from any of computers (both Employees' and from inside our LAN) and set up OpenVPN client on our Internal Server (accessible only from LAN), so that it would allow access to PC1-PC3 from any computer connected to the same OpenVPN server. Is that possible somehow? If so, how should I set up these computers?
If only per-port access to PC1-PC3 is accessible, so Internal Server would work like any ordinary router with port forwarding, it would be sufficient, as we need only single, RDP port on any given machine accessible from network.
Our VPS machine is Windows Server 2012,
Internal Server is Debian Jessie,
PC1-PC3 are Windows machines