Free Linux Firewalls provide a robust and reliable defense against hackers. They prevent personal or business systems from becoming victims of malware attacks when connected to the Internet. Linux firewalls are generally user-friendly and crucial in securing networks and Linux-based computers.
A typical Linux firewall positions itself between your system and the Internet, cleansing all incoming traffic before it reaches the internal network.
Therefore, from a cybersecurity perspective, having a firewall is essential to prevent unauthorized access to the system.
Although Linux has a default firewall integrated directly into the kernel, using it is not the easiest method. While setting up this dedicated firewall requires sufficient expertise, Linux can effortlessly deploy a specialized firewall.
The following sections introduce some of the best free Linux firewalls.
How to Choose the Best Free Linux Firewalls
Selecting the best Linux firewalls involves considering several criteria. The primary criteria include ease of setup, user-friendly interface, and firewall configuration method. Afterward, you should review the available documentation and examine the offered features.
Additionally, the frequency of security updates and whether the firewall is suitable for home use or professional deployment should be checked.
What Criteria Were Used to Evaluate These Firewalls?
The listed firewalls were evaluated based on features and performance. Criteria included execution speed, ease of implementation, interface simplicity, stability, and reliability. Moreover, the availability of up-to-date documentation and active online forums or official support was assessed.
The frequency of security updates and the firewall’s ability to detect and prevent intrusions were also considered.
Furthermore, the presence of a web-based interface and whether the firewall is suitable for home or professional use were evaluated.
1. IPFire
- Pros: Easy setup, various management options, Packfire package management.
- Cons: Supported by a relatively small community of specialists.
IPFire is one of the best free Linux firewalls with a user-friendly interface. It is a stateful firewall based on Netfilter, initially developed as a fork of IPCop but later rewritten from scratch based on Linux.
IPFire can be installed on various hardware, including ARM processors like the Raspberry Pi. During installation, you can segment your network into different security zones, each indicated by a distinct color. For instance, the green zone represents the secure local wired network, while the red zone represents the Internet. No traffic can pass from the red zone to other zones unless specifically configured.
IPFire also includes intrusion detection and prevention capabilities and can function as a VPN server. Additionally, it can be extended using a set of useful plugins to enhance its capabilities.
2. OPNsense
- Pros: Feature-rich, based on HardenedBSD, regular security updates.
- Cons: The user interface is not very intuitive.
OPNsense is the result of merging two open-source projects, pfSense and m0n0wall. It is one of the most scalable free Linux firewalls, built on HardenedBSD, a security-focused variant of FreeBSD.
OPNsense operates as a Firewall as a Service (FWaaS) and is a powerful routing platform. In addition to traffic filtering, it can act as a network gateway, implement traffic shaping, detect and prevent intrusions, set up a VPN, and more.
The firewall provides a stateful firewall with a web-based interface, allowing users to group firewall rules in different categories — a vital feature in the networking domain. It also uses deep packet inspection (DPI) to analyze data packets and connections and prevent malicious content from reaching the recipient.
3. pfSense
- Pros: Simple and intuitive interface, comprehensive features, well-documented.
- Cons: Complex installation process.
pfSense, another popular free Linux firewall, is based on FreeBSD and is widely regarded as one of the most reliable open-source firewalls.
Like OPNsense, pfSense is both a robust firewall and a routing platform. It includes many features, including intrusion detection, VPN setup, and network monitoring. It can be fully managed through a user-friendly web interface.
Moreover, pfSense has extensive documentation and numerous tutorials, making it easy for novice and advanced users to deploy and maintain.
4. ClearOS
- Pros: Easy management, customizable, and abundant documentation.
- Cons: Outdated documentation.
ClearOS is a CentOS-based distribution that can completely replace commercial server distributions like Red Hat Enterprise Server or Windows Small Business Server.
Various editions of ClearOS are available for free download and installation. ClearOS provides several network services, including a firewall with content filtering and intrusion detection.
ClearOS is particularly suited for users with minimal technical expertise. With a few clicks, you can configure and manage the firewall and enable network services based on your needs.
5. OpenWRT
- Pros: Excellent Wi-Fi support, high performance, extensive plugin support.
- Cons: Initial setup can be time-consuming.
OpenWRT is one of the best free Linux firewalls specifically designed for routers. Unlike the other firewalls mentioned, OpenWRT is tailored for routers and networks, making it ideal for advanced users, network enthusiasts, and wireless device developers.
For over 15 years, OpenWRT has been a go-to solution for many enterprises and professionals. Despite the emergence of many Linux firewalls, OpenWRT continues to be actively supported.
It features a visually appealing web interface and offers various optional packages, allowing users to customize it for multiple purposes, from wireless network management to advanced firewall settings.
Conclusion
Each firewall provides unique features and capabilities for different use cases, from simple home network protection to enterprise-level security.
- IPFire and pfSense are ideal for general users and small businesses seeking a balance between functionality and simplicity.
- OPNsense and OpenWRT cater to advanced users and enterprises with complex networking needs.
- ClearOS is well-suited for users with minimal technical expertise looking for a simple, easy-to-manage firewall solution.
Choosing the proper firewall depends on specific requirements, such as interface usability, feature set, and level of customization. Therefore, assessing each firewall against the earlier criteria will help make an informed decision.