ufw - Uncomplicated Firewall

Uncomplicated Firewall，簡稱 UFW，是 Ubuntu 系統上預設的防火牆組件。UFW 是為輕量化組態 iptables 而開發的一款工具。UFW 提供一個非常友好的介面用於建立基於 IPV4，IPV6的防火牆規則。UFW 在 Ubuntu 8.04 LTS 後的所有發行版中預設可用。

Tutorials

• Linux Firewalls: Uncomplicated Firewall (ufw)
• Using Firewall With UFW in Ubuntu Linux [Beginner's Guide] (itsfoss.com)

Basic Commands

# Install
sudo apt-get install ufw

# Enable the UFW
sudo ufw enable
sudo ufw status

# Allow the services and ports
sudo ufw allow OpenSSH
sudo ufw allow 655

For Cloudflare Traffic

Cloudflare publishes the IP addresses of its servers online.

# For HTTP with IPv4 
sudo ufw allow from 173.245.48.0/20 to any port http
sudo ufw allow from 103.21.244.0/22 to any port http
sudo ufw allow from 103.22.200.0/22 to any port http
sudo ufw allow from 103.31.4.0/22 to any port http
sudo ufw allow from 141.101.64.0/18 to any port http
sudo ufw allow from 108.162.192.0/18 to any port http
sudo ufw allow from 190.93.240.0/20 to any port http
sudo ufw allow from 188.114.96.0/20 to any port http
sudo ufw allow from 197.234.240.0/22 to any port http
sudo ufw allow from 198.41.128.0/17 to any port http
sudo ufw allow from 162.158.0.0/15 to any port http
sudo ufw allow from 104.16.0.0/12 to any port http
sudo ufw allow from 172.64.0.0/13 to any port http
sudo ufw allow from 131.0.72.0/22 to any port http

# For HTTP with IPv6
sudo ufw allow from 2400:cb00::/32 to any port http
sudo ufw allow from 2606:4700::/32 to any port http
sudo ufw allow from 2803:f800::/32 to any port http
sudo ufw allow from 2405:b500::/32 to any port http
sudo ufw allow from 2405:8100::/32 to any port http
sudo ufw allow from 2a06:98c0::/29 to any port http
sudo ufw allow from 2c0f:f248::/32 to any port http

# For HTTPS with IPv4
sudo ufw allow from 173.245.48.0/20 to any port https
sudo ufw allow from 103.21.244.0/22 to any port https
sudo ufw allow from 103.22.200.0/22 to any port https
sudo ufw allow from 103.31.4.0/22 to any port https
sudo ufw allow from 141.101.64.0/18 to any port https
sudo ufw allow from 108.162.192.0/18 to any port https
sudo ufw allow from 190.93.240.0/20 to any port https
sudo ufw allow from 188.114.96.0/20 to any port https
sudo ufw allow from 197.234.240.0/22 to any port https
sudo ufw allow from 198.41.128.0/17 to any port https
sudo ufw allow from 162.158.0.0/15 to any port https
sudo ufw allow from 104.16.0.0/12 to any port https
sudo ufw allow from 172.64.0.0/13 to any port https
sudo ufw allow from 131.0.72.0/22 to any port https