I have Windows PC behind a NAT/Firewall at home, and a Windows PC behind a NAT/Firewall at work. i.e. Neither PC has a publicly visible IP address. On each of the PCs, I am running a Ubuntu VM on VirtualBox.
My IT folks at work will not let me SSH from outside into my Windows machine or the Ubuntu VM running on that machine, nor will they open any ports to make my machine accessible, nor will they give me a publicly visible IP address for my Windows PC or Ubuntu VM. But I can SSH out (as I often do to manage Amazon EC2 instances).
I would like to SSH from my (unaddressable) home machine to my (unaddressable) work machine so that I can run software on my work machine from home. All of the solutions I found on the internet require that one of the VMs be network-addressable, but none solve the problem when both machines are unaddressable. I'm willing to cough up a few bucks to rent a cheap Digital Ocean server to bridge the communication between the Ubuntu VMs.
Is there a way that I can configure a set of SSH tunnels between my Ubuntu VMs and the external Digital Ocean server which will make my Ubuntu VM at work addressable via SSH from my Ubuntu VM at home? I am willing to make this work by setting up a SSH tunnel from each Ubuntu VM to the (addressable) Digital Ocean server (with the SSH command originating from the Ubuntu VM).