There is a Remote Server in a large company behind a firewall. You own the MiddleServer, a public available SSH server. Last but not least there is your Workstation – you want to control the RemoteServer from this machine.
:3389 <---Remote Tunnel-->:12344<--Local Tunnel->:12333
In other words, this is a RDP-over-SSH tunnel…
On the RemoteServer, start a SSH session to the MiddleServer. Change to the “Tunnels Tab” and enter the REMOTE forwarded port:
Forward Port 3389 from localhost to Port 12344 of the MiddleServer (Remote port).
Now start a session from your Workstation to the MiddleServer:
We forward our local port 12333 the MiddleServer port 12344.
And now fire-up the Terminal Server Client (mstsc.exe):
Now you control the RemoteServer without change any firewall rules…
One final note: use the “Keep Alive” option in Putty, so the idle connection (RemoteServer – MiddleServer) will not be closed: