How to create a server-level firewall
You can restrict VPS incoming connections within your VPS provider’s admin page (at a network-level), but if you can’t restrict outgoing connections, or you prefer to use a firewall at a server-level. you can use
This is an example of how
ufw works. We are going to restrict our incoming connections to a specific IP. Replace “IP” with your chosen IP.
You may need to start and enable
sudo ufw default deny incoming sudo ufw default allow outgoing sudo ufw allow from IP sudo ufw enable
To allow a specific port:
sudo ufw allow 1050
If you use Docker,
-p flag makes the selected port available to everyone regardless of your
ufw configuration, so you need to use
--network host instead.
docker run -d --network host nginx