How to setup a Wireguard server behind the Firewall

safe_net

Behind my Zyxel firewall (USG Flex 50) I run a Qnap NAS with a Wireguard server. In order to access this device from outside, I have set up the Wireguard server on the NAS. But I have no idea, how I need to setup the firewall in order to reach my NAS over the Wireguard tunnel - also asking Dr. Google didn't really help.
Does anybody was already successful to setup such a Wireguard tunnel behind the Zyxel? 

Zyxel_Stanley

Hi @safe_net
You can have a check the tutorial on QNAP website.
If QNAP Wireguard server is behind FLEX50(NAT router), the one thing of FLEX50 need to do is creating port forwarding rule to forward VPN traffic from WAN to LAN.

e.g. Default Wireguard VPN service port is UDP 51820

Of course, you have to allow the traffic from WAN to QNAP(Intranet)
You can refer to the FAQ of port forwarding, it is the same thing.