Port forwarding properly and letting PiVPN do the rest (with DynDNS on the router)

Using PiVPN it’s only a few button pushes and config details to set up a VPN on a RPi or Debian/Ubuntu server. The main bother is that the port forwarding needs to be right (1194 or some other port on *UDP* from the outermost router right to the Pi), and that a DynDNS service is needed if the public IP address will be changing. In my case since it’s a home internet connection the IP can change at any time, so halfway through the install process I signed up for a no-IP address and set up DDNS on the outermost router.