10 Best Free and Open Source Firewall Solutions for Small Businesses

When it comes to securing your small business, there are a lot of different things to consider. However, choosing the right firewall solution is one of the most important. There are a lot of different firewall options out there, both free and paid. However, it’s often best for small businesses to go with a free and open-source solution. There are a lot of benefits to using a free and open-source firewall. First of all, they’re usually more affordable/free than their paid counterparts. Additionally, they’re often more customizable and flexible, meaning you can tailor them to fit your small business’s needs better. To help you find the best free and open-source firewall solution for your small business, we’ve compiled a list of 10 of the best options. All of these firewalls come with a wide range of features. In this blog post, we’ll be taking a look at 10 of the best free and open-source firewall solutions for small businesses. We’ll be looking at features, ease of use, and more to help you decide which firewall is right for you. Whether you’re looking for a simple solution or something with more bells and whistles, we’ve got you covered. So without further ado, let’s get started!

1. pfSense firewall / router

pfSense is a free and open-source firewall solution that can be installed on a physical or virtual machine. It offers a web-based interface for easy administration and includes a wide range of features such as support for multiple WAN connections, traffic shaping, VPN support, and more. It is an all in one solution that can function as both a network firewall and an Edge / LAN router.

2. IPFire

IPFire is another popular free and open-source firewall solution. It offers an easy-to-use web interface and comes with a wide range of features including intrusion detection, content filtering, and VPN support.

3. ClearOS

ClearOS is a free and open-source firewall solution that is designed for small businesses. It offers an easy-to-use web-based interface and includes features such as Intrusion Detection/Prevention, Spam Filtering, Web Content Filtering, and more.

4. IPCop

IPCop is a free and open-source firewall solution that is designed for home and small office use. It offers an easy-to-use web interface and comes with a variety of features such as intrusion detection, content filtering, bandwidth control, and more.

5. Endian Firewall Community

Endian Firewall Community is a free and open-source firewall solution that is based on the popular Endian Firewall product. It offers an easy-to-use web interface and comes with all of the same features as the commercial version, including intrusion detection, content filtering, VPN support, and more.

6. OPNSense

OPNSense is a free and open-source firewall solution that is based on the popular pfSense project. It offers an easy-to-use web interface and comes with all of the same features as pfSense, including support for multiple WAN connections, traffic shaping, VPN support, and more.

7. Perimeter81 Firewall

The Perimeter81 firewall is a stateful firewall that offers protection for your network against external threats. It’s easy to set up and manage, and it’s affordable, making it a great option for small and medium-sized businesses. The firewall uses a variety of security features to keep your network safe, including intrusion detection and prevention, malware protection, and web filtering. It also offers advanced features like VPN support and two-factor authentication

8. IPTables

Iptables is a Linux command line tool used to set up, maintain, and inspect the tables of IP packet filter rules in the Linux kernel. Several different tables may be defined. Each table contains a number of built-in chains and may also contain user-defined chains. Chains are containers for rules.

Iptables uses a set of tables which have a number of built-in chains. These are the filter table (which has a built-in INPUT chain), the nat table (which has built-in PREROUTING, INPUT, OUTPUT and POSTROUTING chains), the mangle table (which has built-in PREROUTING, INPUT, FORWARD, OUTPUT and POSTROUTING chains) and the raw table (which has built-in PREROUTING and OUTPUT chains).

Iptables has a number of command line options. The most important ones are listed below:

-A : Append one or more rules to the end of the selected chain
-D : Delete one or more rules from the selected chain
-R : Replace a rule in the selected chain at the specified position
-I : Insert one or more rules in the selected chain at the specified position
-L : List all rules in the selected chain
-F : Flush (delete all rules) from the selected chain
-Z : Zero the packet and byte counters in the selected chain
-N : Create a new user-defined chain
-X : Delete a user-defined chain
-P : Change the policy for the selected chain to ACCEPT, DROP or RETURN
-h : Help

9. Shorewall Firewall

You can think of Shorewall firewall as a simplified version of IPTables firewall. It is a free and absolutely open source firewall product designed to make your LAN / Corporation / Enterprise network much more secure. It ships with many features that include: Masquerading/SNAT, Port Forwarding (DNAT), One-to-one NAT, Proxy ARP, NETMAP, Multiple ISP support and more

10. Smoothwall Express

Smoothwall Express is an open source and free network protection solution designed for digital safety for your users. It is a firewall solution initially released in the year 2000 and comes with 3 release types:

1. Standard – This is the normal release type for users.
2. Developer – This is a release targeted at people who want to work on Smoothwall Express.
3. Offroad – A cut down version for people who want to ensure their system’s hardware is compatible with Smoothwall Express.