Best Firewall Software for Linux of 2025

Heimdal® Endpoint Detection and Response is our proprietary multi-solution service providing unique prevention, threat-hunting, and remediation capabilities. It combines the most advanced threat-hunting technologies in existence: Heimdal Next-Gen Antivirus, Heimdal Privileged Access Management, Heimdal Application Control, Heimdal Ransomware Encryption Protection, Heimdal Patch & Asset Management, and Heimdal Threat Prevention. With 6 modules working together seamlessly under one convenient roof, all within one agent and one platform, Heimdal Endpoint Detection and Response grants you access to all the essential cybersecurity layers your business needs to protect itself against both known and unknown online and insider threats. Our state-of-the-art product empowers you to quickly and effortlessly respond to sophisticated malware with stunning accuracy, protecting your digital assets and your reputation in the process as well.

For IT professionals to stop ransomware, you need to do more than look for threats. ThreatLocker helps you reduce your surface areas of attack with policy-driven endpoint security and change the paradigm from only blocking known threats, to blocking everything that is not explicitly allowed. Combined with Ringfencing and additional controls, you enhance your Zero Trust protection and block attacks that live off the land. Discover today the ThreatLocker suite of Zero Trust endpoint security solutions: Allowlisting, Ringfencing, Elevation Control, Storage Control, Network Access Control, Unified Audit, ThreatLocker Ops, Community, Configuration Manager and Health Center. 

Kamatera offers robust cloud firewall solutions designed to safeguard cloud servers and private cloud networks from various attacks. Our team of cloud security professionals is dedicated to configuring cloud firewalls and continuously monitoring server activities in real-time. We prioritize your data's security by assessing and filtering data packets to determine their origin, destination, and content, allowing only verified and authorized packets to access your servers. Our cloud firewalls provide a comprehensive, all-in-one security solution, seamlessly integrating with all virtual appliances for thorough protection. In addition, Kamatera’s cloud firewalls can serve as a hardware VPN server, effectively managing all network traffic without the need for supplementary VPN services. Thanks to their adaptability and limitless scalability, our cybersecurity offerings cater to individuals, small and medium-sized businesses, as well as large enterprises. A single cloud firewall is capable of safeguarding your entire cloud infrastructure.

Imunify360 provides security solutions for web-hosting servers. Imunify360 is more than antivirus and WAF. It combines an Intrusion Prevention & Detection system with an Application Specific Web Application Firewall, Real time Antivirus protection, and Patch Management components into one security suite. Imunify360 is fully automated and displays all statistics in an intuitive dashboard.

NextDNS offers comprehensive protection from various security risks, effectively blocking advertisements and trackers across websites and applications while ensuring a secure and monitored online experience for children on all devices and networks. You can assess your security needs and customize your protection by activating over ten different safety measures. By utilizing reliable threat intelligence feeds that contain millions of harmful domains and update constantly, you can enhance your defense mechanisms. Our system goes beyond merely tracking domains; it evaluates DNS queries and responses instantaneously, allowing for the swift identification and prevention of harmful activities. Given that there is often only a brief window of hours from when a domain is registered to when it is used in an attack, our advanced threat intelligence framework is designed to identify malicious domains more efficiently than traditional security methods. Additionally, you can effectively eliminate advertisements and trackers in both websites and applications, including even the most sophisticated ones, by leveraging the most widely used ad and tracker blocklists, which include millions of domains that are refreshed in real-time. Ultimately, NextDNS empowers users with tools to create a safer browsing environment tailored to their specific security needs.

Multilayered endpoint security utilizing behavior-based analysis offers robust defenses against both familiar and emerging threats. It provides complete real-time oversight of your entire software inventory, regardless of location. The FortiClient endpoint protection service, tailored for small and medium enterprises, is delivered via the cloud. This cohesive endpoint protection platform delivers automated next-generation threat defense, granting visibility and control over your software and hardware assets within the broader security framework. It enables the identification and remediation of vulnerable or compromised systems throughout your attack surface. As an integral component of the Fortinet Security Fabric, FortiClient connects endpoints to enhance early detection and prevention of sophisticated threats. Security events, including zero-day malware attacks, botnet identifications, and detected vulnerabilities, are communicated instantly. With its comprehensive approach, this solution not only safeguards your assets but also streamlines security management.

IPFire is an advanced, robust, and secure Open Source firewall built on the Linux platform. Its user-friendly interface, exceptional performance across various environments, and adaptability make it suitable for a wide range of users. Prioritizing security above all, IPFire is fortified to defend against online threats while simultaneously safeguarding your network from potential intrusions. The firewall's robust engine and its integrated intrusion prevention system work in tandem to shield your network from cyber attacks and denial-of-service threats. Developed as free software by a collaborative community, IPFire is trusted by hundreds of thousands of users globally. The core aim of IPFire is to ensure maximum security, and it is designed for easy configuration to establish a firewall engine that effectively blocks unauthorized access. By default, IPFire organizes the network into distinct zones with tailored security policies, such as LAN and DMZ, allowing for effective risk management and customized configurations to cater to specific requirements. This thoughtful design enhances the overall security posture of any network it protects.

Our Linux virtual machines simplify cloud infrastructure and provide a robust set of tools that make it easy to develop, deploy, scale, and scale modern applications faster and more efficiently. Linode believes virtual computing is essential to enable innovation in the cloud. It must be accessible, affordable, and easy. Our infrastructure-as-a-service platform is deployed across 11 global markets from our data centers around the world and is supported by our Next Generation Network, advanced APIs, comprehensive services, and vast library of educational resources. Linode products, services and people allow developers and businesses to create, deploy, scale, and scale applications in the cloud more efficiently and cost-effectively.

The pfSense project provides a free network firewall distribution. It is based on FreeBSD's operating system with a custom kernel. Third-party free software packages are also included. The package system allows pfSense software to offer the same functionality as or more common commercial firewalls without any artificial limitations. It has replaced every major commercial firewall in many installations around the globe, including Check Point and Cisco PIX, Cisco ASA and Juniper.

Fortinet stands out as a prominent global entity in the realm of cybersecurity, recognized for its all-encompassing and cohesive strategy aimed at protecting digital infrastructures, devices, and applications. Established in the year 2000, the company offers an extensive array of products and services, which encompass firewalls, endpoint security, intrusion prevention systems, and secure access solutions. Central to its offerings is the Fortinet Security Fabric, a holistic platform that effectively melds various security tools to provide enhanced visibility, automation, and real-time intelligence regarding threats across the entire network. With a reputation for reliability among businesses, governmental bodies, and service providers across the globe, Fortinet places a strong emphasis on innovation, scalability, and performance, thereby ensuring a resilient defense against the ever-evolving landscape of cyber threats. Moreover, Fortinet’s commitment to facilitating digital transformation and maintaining business continuity further underscores its role as a pivotal player in the cybersecurity industry.

Traditional packet filters are gradually becoming outdated, as even open-source solutions are shifting towards Next-Generation Firewalls. OPNsense stands out as a leading option for features like intrusion detection, application control, web filtering, and antivirus protection. No network, regardless of its size, is immune to potential attacks; even devices in home networks, such as washing machines and smartwatches, are at risk and need robust security measures. Firewalls play a crucial role in a comprehensive security strategy, shielding systems from both established and emerging threats. The effectiveness of a firewall is maximized when its capabilities are well understood, it operates intuitively, and is strategically placed within the network infrastructure. OPNsense rises to the occasion by fulfilling these essential requirements in various ways. This book serves as an invaluable guide for anyone looking to comprehend, install, and configure an OPNsense firewall effectively. Ultimately, understanding the intricacies of OPNsense can empower users to create a more secure digital environment.

Data is the most valuable asset of your company, so it is important to protect it. Network security is about zero trust. You should never trust anyone outside or within your network perimeter. Network security is becoming more difficult because network perimeters are blurring and endpoints continue proliferating. Cyberattacks are also being launched using machine learning and automation. Organizations are shifting to the cloud to protect their data in a hybrid cloud/on premises environment. This is without adding cost or complexity. A huge step towards secure environments is the combination of micro-segmentation and real-time network governance. You can improve your security posture through automation and data by choosing the right software solution. ditno is a cybersecurity management platform that offers a zero trust network approach to simplify and improve security.

Open source software and a universal router are key to democratizing the way we access networks. VyOS' vision is to revolutionize how we access networks, so that everyone can build the solutions they have always wanted, without limitations, restrictions, or prohibitive prices. We believe that internet access is just as important to human development as food, water, air, and healthcare. VyOS was founded by engineers for engineers. It is an open-source software company that makes it possible to access networks without restrictions or prohibitive fees. Through our open-source software and virtual platforms, we do this as VyOS. Stateful firewalls, zone based firewall, all types source and destination NAT (one-to-one, one-to many, many to many). For auditing, creating customized images and contributing, everyone has access to the entire codebase and build toolchain.

AP Lens is a Sandbox Browser designed to enhance network security through DNS Whitelisting, effectively preventing attacks from penetrating the network. What features does AP Lens offer? - Web Filtering: Offers adaptable and user-friendly options for content blocking. - Anti-Phishing: Eliminates look-alike domains with complete precision. - Ransomware Protection: Safeguards the network while allowing business applications to function smoothly. - Secure Remote Work: Implements internet usage policies efficiently without the delays associated with VPNs. - No More 0-Day Attacks: Overcomes the limitations of traditional blacklisting through the AP Lens Augmented Whitelist. - Compliant: Aligns with regulatory standards set forth by cybersecurity insurance policies. - One-Click Installation: Allows for quick setup without requiring extensive user intervention or updates. - No Maintenance: Prevents malware and phishing threats without the need for ongoing oversight. With a foundation built on over 20 years of expertise in cybersecurity, cloud security, and information protection across various sectors, including private banking and public services, our team is equipped to address the evolving challenges in digital security.

CrowdSec, a free, open-source, and collaborative IPS, analyzes behaviors, responds to attacks, and shares signals across the community. It outnumbers cybercriminals. Create your own intrusion detection system. To identify cyber threats, you can use behavior scenarios. You can share and benefit from a crowdsourced, curated cyber threat intelligence platform. Define the type and location of the remediation you wish to apply. Use the community's IP blocklist to automate your security. CrowdSec can be run on containers, virtual machines, bare metal servers, containers, or directly from your code using our API. Our cybersecurity community is destroying cybercriminals' anonymity. This is our strength. You can help us create and distribute a qualified IP blocklist that protects everyone by sharing IP addresses you have been annoyed by. CrowdSec can process massive amounts of logs faster than Fail2ban, and is 60x faster than Fail2ban.