Firewall

Install and Use UFW (Uncomplicated Firewall)

  • Enables UFW and displays its status
sudo apt-get install ufw
sudo ufw enable
sudo ufw status

Allow/Deny Services

  • Allows or denies specific services.
sudo ufw allow ssh
sudo ufw allow 80/tcp
sudo ufw deny 23/tcp

Install and Use iptables

  • Installs and lists iptables rules.
sudo apt-get install iptables
sudo iptables -L

Basic iptables Rules

  • Adds basic rules to allow SSH or HTTP traffic and drop all other traffic.
sudo iptables -A INPUT -p tcp --dport 22 -j ACCEPT
sudo iptables -A INPUT -p tcp --dport 80 -j ACCEPT
sudo iptables -A INPUT -j DROP