Configure OpenVPN with IPv6 IPv4 on Qnap NAS
You have a Qnap NAS and want to access your data on the go? This is relatively easy to set up. All you need is an OpenVPN program on your Mac (like Viscosity) and the OpenVPN server (the program) on the NAS. This is about how to set it up on the Qnap. You can find the setup of Viscosity in this article.
The access to a Qnap NAS (as well as Synology) via VPN we consider as the most secure way to access the data of the storage box - as long as all other access ways are additionally disabled. The advantage is that only one port in the router has to be open for the NAS and that only the OpenVPN software exposes itself to the Internet, which was explicitly created for this purpose.
OpenVPN IPv6 configuration on Qnap NAS
Currently, a connection via IPv6 is not yet possible on Qnap devices. Only Synologys can do this to some extent.
OpenVPN IPv4 configuration on Qnap NAS
If you haven't already found and installed OpenVPN out of curiosity, go to the Qnap App Center and install "QVPN". Then open the QPVN program and enable "OpenVPN".
That would give us a slider green already, a nice thing. :) Now go to the Privilege Settings on the left and check "OpenVPN" for the users that are allowed to connect via OpenVPN. If you forget to check this box, you can do whatever you want later, a connection will simply not be established.
For the detailed settings we go to the menu item OpenVPN on the left. There you can see that now the OpenVPN server is started and every device that logs in gets an IP from the 10.8.0.x range. The Qnap itself has the address 10.8.0.1 - but also, and this will come in handy later, the address of your home network, for example 192.168.178.5. The advantage of this circumstance is immense: If you have created shortcuts in the Finder for your NAS folders, for example, they are now also accessible via the VPN without having to change anything! So OpenVPN knows that 10.8.0.1 is the address of the Qnap in the VPN and also reacts to the home network address at the same time, so that all shortcuts just work. So this duplicate IP address for one device makes life much easier.
If you want to do the same for other devices in your network, e.g. access your router with 192.168.178.1, then check the box "Use this connection as a default gateway for remote devices". If you don't want that and the access should be limited to the NAS, then don't check it - then you can only access the Qnap NAS.
That's it with the configuration! Now press the button Download Certificate and/or configuration file and read on how to set up Viscosity on your Mac as OpenVPN client to access the NAS. The download should provide you with a .crt and an .ovpn file (probably zipped). You should have already enabled a suitable port in your router (examples: FritzBox, DrayTek). This is the only way to reach the NAS from outside.