–I left the Global Discovery Servers at default –I gave each machine a unique Port number under the Sync Protocol Listen Address –I forwarded both of those Ports using the VPN Client Area… I ran the VPN tcp test, and it said the Ports are reachable… –I added the Ports to my IPtables list (on the Linux machine) (I turned the Firewall off on the Windows machine & on the router, so nothing would interfere with my testing…) –I manually forwarded the ports on my router… & restarted,
I turned on the VPN, at first I thought it was not working… But, I was not waiting long enough for it! (…because when the VPN was turned off; both machines would connect pretty much straight away!) DOH! both machines seem to connect now, but first, after a small delay of under 5 minutes!
–Thanks for all the Help and Advice