I am attempting to route to an airgapped network via a teltonika cell modem using zerotier. I can ping the teltonika via zerotier from my Laptop- so that much is good. All looks online and happy between my laptop and the Teltonika.
My next step is to initiate a remote desktop sharing session using TightVNC (or similar). I need to see the desktop of a PC on the Teltonica’s LAN port. The ONLY internet connection to that PC is through the Teltonika and it is set to not route internet to items on the LAN (so I don’t get the onsite guys downloading who knows what via my cell connection as I choke on data usage fees). Also I cannot have this target PC being a permanent part of my Zerotier network. This needs to be a one-way street. Me to the target when needed. Not the other way around.
I used to do this same setup through a Tosibox on this same site, using Tight VNC - but the Tosibox needs to go. I had similar settings over there - the Internet as set to not be accessible via the LAN port.
I tried to hit the Teltonika via TightVNC (as a test) and it says the device refused the connection - which is perfect. It means that I can reach it and it behaves as expected. But I cannot get to the IP of the PC on the other side of the Teltonika. How do I bridge that gap? I would imagine I need to set up routing in Zerotier. I did set up a route from my 172.xxx zerotier IP to the local 192.168 network that is on the LAN plug. No dice. I am missing something. Probably staring me in the face - you know how that goes.