Understanding Firewalls

1) What is a firewall

A firewall acts as your device’s first line of defense. It filters network traffic to decide what should be allowed in or out, keeping threats out and protecting your data. This matters at home, on public Wi-Fi, and on servers in the cloud.

Linux offers flexible tools for this protection, from beginner-friendly interfaces to advanced configurations used by administrators and security teams.

2) Firewall tools on Linux

UFW is designed for simplicity and is great for desktops or anyone who wants quick control without complex syntax. For example, sudo ufw enable activates your firewall quickly.

iptables provides traditional, granular control and is common on systems that need fine-tuned rules for performance or compliance.

nftables is the modern replacement for iptables. It offers better performance and a cleaner rule model. Many distributions use nftables by default.

Recommendation: most desktop users can start with UFW for a safe and simple setup. Servers benefit from nftables for efficient, maintainable policies.

3) Role-based firewall profiles

The CyberLife Firewall Configurator includes profiles that match common use cases.

• Desktop or Laptop focuses on everyday browsing and applications, while blocking unsolicited inbound traffic.
• Web Server allows secure web traffic on ports 80 and 443 and enables SSH for maintenance.
• Developer permits local development services while preserving safe boundaries.

These profiles adjust key rules automatically so you avoid common mistakes and stay secure.

4) Advanced options explained

Country Blocking limits traffic from selected regions using IP sets. Use carefully because legitimate services may operate from those ranges.

Allow My IP exempts your current address to prevent lockouts, especially useful when configuring remote servers over SSH.

Logging records what is allowed or blocked. This is essential for troubleshooting and learning how rules behave.

IPv6 Support ensures your firewall covers both IPv4 and IPv6 so all network paths are protected.

5) Best practices

• Keep your firewall enabled at all times.
• Test new rules on a non-critical machine or VM before production use.
• Review logs regularly to detect unwanted access attempts.
• Combine firewall protection with OS updates, strong passwords, and multi-factor authentication.
• Back up your current configuration before major changes.

These habits reduce risk and make troubleshooting easier.