How to: Make AdGuard UI and DNS service ports only accessible via VPN

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I was fiddling around a bit with ufw and decided to share my results with you: How to Make AdGuard UI and DNS service ports only accessible via VPN
Note: by enabling ufw you can block new connections required to manage your server (SSH). Make sure you keep an SSH connection to your server open and test the rules by opening a another SSH connection. Otherwise you risk loosing access to your server!

1. Reset ufw to defaults

sudo ufw default deny incoming
sudo ufw default allow outgoing

2. Allow SSH access

sudo ufw allow ssh

3. Allow access to the Wireguard VPN server (in this case the default port used in this tutorial)

sudo ufw allow 51820

4. Identify network adapter used by Wireguard (can be identified by a name starting with "wg" followed by a number, if you start with a fresh install and follow this tutorial it should be wg0)

ip link show

5. Allow access to all ports by requests coming from the Wireguard network adapter

sudo ufw allow in on wg0

6. Enable ufw

sudo ufw enable

7. Check the status of ufw

sudo ufw status numbered

I hope you find these rules useful. Feedback, modifications and suggestions are welcome 😊