How to setup a firewall with UFW on Debian

Uncomplicated Firewall (ufw) is a tool for managing firewall designed to be easy to use. It uses a command-line interface and uses iptables for configuration.

Installation

  sudo apt-get install ufw

Setup

• Allow main ports and ports you need to expose:

  sudo ufw allow 22
  sudo ufw allow 80
  sudo ufw allow 443

• Deny all other ports and allow outgoing connections:

  sudo ufw default deny incoming
  sudo ufw default allow outgoing

• To delete a rule you can use:

  ufw delete allow 80

• Before enable the firewall, remember to allow connections from ssh port if you are connecting remotely to your vps:

  sudo ufw enable

• To verify the firewall is running you can use the command:

  sudo ufw status