Best Free and Open Source Alternatives to Cisco Secure Firewall

Last Updated on February 15, 2024

Cisco Systems, Inc. is an American multinational technology corporation that focuses on networking hardware and software. It has over 75,000 employees with its headquarters in San Jose, California.

Cisco has been participating in open source development for almost 30 years including founding projects like OpenDaylight,, VPP, PNDA, SNAS, and OpenH264, and contributing to projects like OPNFV, Kubernetes, OpenStack, Ansible, Chef, Puppet, Maven, and many others.

Cisco has also been a key contributor to the Linux kernel over the years, accounting for about 0.5% of total kernel commits, and is a Platinum Member of the Linux Foundation and Premium Sponsor of the Open Source Initiative.

From a software perspective, Cisco’s main focus is developing proprietary programs. In this series we look at free and open source alternatives to their products.

Cisco Secure FirewallSecure Firewall is a complete security portfolio that protects your applications and users. It includes a Snort 3 next-generation intrusion prevention system.

What are the best free and open source firewall solutions?

1. IPFire

IPFire is a Linux-based stateful firewall distro that’s built on top of Netfilter, the Linux packet filtering framework. Besides its easy to configure firewall engine, IPFire also has intrusion detection and prevention capabilities, and can also be used to offer VPN facilities. IPFire supports industry standards like IPsec and OpenVPN and interoperates with equipment from various vendors like Cisco & Juniper. VPNs are quickly and easily set up with IPFire and employ latest cryptography.

IPFire is built from scratch and not based on any other distribution.

We like that IPFire is easy to configure, there are multiple deployment options, and Pakfire package management.

2. OPNsense

OPNsense is powered by HardenedBSD, which is a security oriented fork of FreeBSD.

OPNsense is designed to serve as a firewall and routing platform and besides filtering traffic can also be used to display a captive portal, shape traffic, detect and prevent intrusions, as well as setup a Virtual Private Network (VPN), and lots more. It implements a stateful firewall with support for IPv4 and IPv6 and live view on blocked or passed traffic. The firewall enables users to group firewall rules by category.

There are lots of features and regular security updates. Like IPFire, it offers integrated support for IPsec (including route based), OpenVPN as well as pluggable support for Tinc (full mesh VPN) and WireGuard.

There’s two factor authentication, web filtering, intrusion detection and prevention, as well as hardware failover, SD-WAN Comparison, and much more.

3. pfSense

pfSense describes itself as the world’s most trusted open source network security solution. Besides being a powerful, flexible firewalling and routing platform, it includes a huge raft of features.

pfSense has an intuitive interface, good documentation, and it’s jam-packed with features.

All articles in this series:

Alternatives to Cisco's Products
AnyConnect SSL VPNAnyConnect SSL VPN gives users secure access to the enterprise network, from any device, at any time, in any location.
DNA CenterDNA Center is a centralized automation and management platform for the entire network.
FirewallSecure Firewall is a complete security portfolio that protects your applications and users. It includes a Snort 3 next-generation intrusion prevention system.
Cisco Secure IDSSecure IDS is a network-based intrusion detection system that uses a signature database to trigger intrusion alarms. The major components are a sensor platform and a director platform.
WebexWebex offers calling, meetings, and messaging in the cloud for teams of all sizes. It offers a way of collaborating that focuses around the work you do, not your location.
Notify of

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Inline Feedbacks
View all comments