Setting Up a Firewall with UFW

UFW (Uncomplicated Firewall) makes managing firewall rules straightforward, even for beginners.

Install UFW

apt install ufw -y

Set Default Policies

ufw default deny incoming
ufw default allow outgoing

Allow Essential Services

ufw allow ssh          # SSH (port 22)
ufw allow 80           # HTTP
ufw allow 443          # HTTPS

Enable the Firewall

ufw enable

View Current Rules

ufw status verbose

Common Operations

ufw allow 25565               # Allow a specific port
ufw delete allow 80           # Remove a rule
ufw allow from 203.0.113.100  # Allow a specific IP
ufw deny from 198.51.100.0    # Block a specific IP
ufw disable                   # Disable the firewall
ufw reset                     # Reset all rules

Note: Always allow SSH before enabling the firewall to avoid locking yourself out.