In this context, we will talk about the best Linux firewalls of 2023. Additionally, we will describe the entire concept and every helpful detail for you to know better about these security solutions. Stay with us!
What is a firewall?
A firewall is a network security program that controls incoming and outgoing connections based on a set of rules. Simply put, it’s a wall between your computer and the outside network that prevents many malicious attacks, threats, and vulnerabilities on your network.
Do you need a firewall?
You might think it’s better to put up a firewall, and you’d be right! However, all Linux distributions come without firewalls. To be more precise, they come with disabled firewalls.
Because the Linux kernel has a built-in firewall, all Linux distros technically have a firewall, which is not configured and enabled. The reason is that using a firewall requires some skill.
However, don’t worry! Your Linux-based system is still protected without an active firewall. By default, most distributions, such as Ubuntu and Linux Mint, do not have any open ports.
Therefore, your computer cannot be accessed by intruders. Nevertheless, we recommend enabling a firewall. It’s better to be safe than sorry! It doesn’t use many resources, but it adds an extra layer of security. An inexperienced user with samba, ssh, or apache installed may accidentally open some ports without knowing. In this case, a firewall will still protect the system.
How to set up a firewall?
There are two ways of setting up a firewall. Here, we try to describe them through some examples:
UFW
UFW is perhaps the most user-friendly firewall available on Linux. If you prefer to have a graphical interface, install GUFW.
How to use GUFW?
To use a GUFW firewall, you may follow these steps:
- Install GUFW.
- Open it.
- Additionally, enable it.
Now, your firewall is enabled, and the default settings to deny incoming and allow outgoing connections are fine for most users. Nobody will be able to connect your computer. At the same time, any application on your system can reach the outside world.
If you need to open some ports to connect to your computer from outside, go to the Rules tab and open ports for specific applications. For example, if you need to access your computer remotely via SSH, you should select the SSH option in the Applications list.
GUFW is a very simple and effective firewall application that can also be used from the terminal. To do this, you need to follow these steps: Open your terminal by
- Pressing Ctrl + Alt + T.
- Type the command below to enable the UFW firewall:
$ sudo ufw enable
- Enter the password.
- Type the following syntax to check its status:
$ sudo ufw status verbose
Now, you can see the rule denies incoming and allows outgoing connections.
If you want to open some ports, it’s easy to run the following command:
$ sudo ufw allow ssh
- That way, you will allow SSH access to your computer.
- If you check the status again, you will see SSH is allowed.
Iptables
Tables are more advanced but probably the correct way to configure a Linux firewall. If you want some hardcore Linux experience, you can try configuring iptables. Understanding iptables is not easy. So, you need to read a lot to understand how it works and how to configure it for your needs. Without going too deep, we will give some tips, which are important for beginners to know. In this firewall, input is a chain used to control the system’s behavior regarding incoming connections and most deny them.
Although the output is a chain used for outgoing connections and accessing Internet websites. Therefore, you mostly leave it open. There is also a forward chain. If you do not make any routing or anything else on your system that requires forwarding, you will not use this chain.
How to use Iptable?
To keep things simple, you can follow these steps:
First, you should type the following syntax in your terminal to create the required chain:
$ sudo iptables –N TCP
Enter the password
If you are using Arch Linux, you can type in the following syntax to enable Iptables on the system:
$ sudo systemctl enable iptables.service
So, it starts with your system.
To make it executable, type following command:
$ chmod +x iptablea_ArchLinux.sh
and run it using the following syntax:
iptables_ArchLinux
- It will implement all necessary rules.
What are the best Linux firewalls in 2023?
Some of the best Linux firewalls of 2023 are as follows:
pfSense
PfSense is an open-source, free UTM Firewall designed and distributed on the basis of FreeBSD. It is used as a comprehensive, integrated threat management solution and central Internet and network bandwidth management.
This free and powerful software has been able to stand up to tough competitors like Juniper and Cisco ASA and has been included in the list of security and firewall contenders.
pfSense user-friendly environment and WEBGUI software, which manages via shell and SSH, with a graphical environment that makes changes, settings, and reporting easy.
This software provides many security features on your network using software packages based on open sources such as Linux and Squid or Scoid or Snort.
Key benefits
Some of the key benefits of pfSense are:
- Real-time monitoring
- Dynamic DNS
- with multiple DNS clients
- Port/IP filtering and limiting network connections
- Built-in load balancing
- Network address translation
- High availability
- Supports OpenVPN and IPsec
- Stores a complete history of resource usage to enable reporting
IPFire
IPFire is an open-source Linux-based distribution that primarily serves as a router and firewall. It is an independent firewall system, providing network administrators with a web-based management console for configuration and settings.
It turns the PC into a router so they can design routing systems and internet gateways and firewalls. IPFire is built on top of NetFilter to provide improved security for enterprise networks.
It consists of a set of hooks in Linux kernel and is used to block and manipulate packets. Therefore, it can act as a device that allows traffic to pass through secure networks and prevents insecure connections.
The simplicity and ease of handling of IPfire are the most important features that make it more popular among users.
Key features
Some of IPFire’s key features are:
- packet inspection
- Intrusion detection system
- Offers a proxy server
- Provides a virtual private network including OpenVPN and IPsec
- WOL capability
- Dynamic DNS
- Offers a DHCP server
VyOS
Vyos is a fully open-source and free firewall written on Debian GNU Linux and can run on both virtual and physical platforms. This software also provides connection management services and supports VPN and network routing capabilities. It supports paravirtual drivers and integration packages on virtual platforms.
In addition, it supports advanced capabilities like dynamic routing and a command line interface.
Key features
Some key features of the Vyos are:
- Traffic instructions
- tunnel interface
- Static and dynamic routing
- sFlow and NetFlow
- Remote Syslog
- Acting when an event occurs (event handling)
- Web proxy & URL filtering (no HTTPS filtering)
- Backup settings remotely
- DHCPv6 and DHCP servers and relays
- VXLAN, Static L2TPv3, SIT, IPIP, GRE, PPPoE
- Network address translation
Untangle
Untangle is an open-source firewall similar to ClearOS and based on Debian 8.4. Its core network security functions are offered with free and paid plans to add additional functions and features, which are managed through a web-based user interface. The technical name of this dynamic firewall is NG, and it can be easily installed in various formats on any hardware or virtual machine.
Key features
Some key features of Untangle Firewall are:
- Web monitoring
- Virus blocking
- Ad blocking
- Open the VPN
- Spam blocking
- Firewall function
- Intrusion prevention
Smoothwall Express
SmoothWall Express is a free, open-source solution with a simple web interface and multiple applications for configuring and managing network connections. It can be stopped or restarted directly through the web interface.
Key features
Some key features of Smoothwall Express are:
- Easy to use
- Specific outgoing connection filtering
- Listing malicious IP addresses to prevent access
- Port forwarding
- DHCP supports external connections over Ethernet, PPPoA, PPPoE, and static Ethernet
- Systematically detecting intrusions
OPNSense
OPNsense is an open-source, free and secure firewall based on FreeBSD and uses two powerful IPFW and PF solutions. It supports both IPv6 and IPv4 and provides best intrusion detection services.
This software is designed to manage network bandwidth in an optimal way. Additionally, it uses Suricata instead of Snort.
Key features
Some key features of OpenSense Firewall are:
- Supports many plugins
- Built-in monitoring and reporting tools
- Detecting intrusions and preventing systems against them
- VPN solution
Endian Firewall Community (EFW)
EFW is a powerful security product based on Linux with easy installation, typically used for small networks. Endian is a hardware device resistant to external attacks with a firewall, antivirus, and anti-filter software. This hardware is considered an efficient security management solution. This flexible firewall protects your network from various attacks and threats.
Key features
Some of EFW’s key features are:
- Provides real-time monitoring
- Advanced secure remote access
- Improves web security
- Improves the security of email services
- Detecting intrusions and preventing systems against them
ClearOS
ClearOS is a Linux firewall based on CentOS designed to completely replace Red Hat Enterprise Server or Windows Small Business Server. It has several versions, including a free community version that provides a variety of network services, a firewall, content filtering, and intrusion detection. You can install and configure this software easily.
Key features
Some Key Features of ClearOs are:
- Bandwidth management
- Content and web proxy filtering
- Detecting intrusions and preventing systems against them
- Provide multiple security layers
- File sharing management
Conclusion
Here, you learn about the best Linux firewalls of 2023 and their key features. Additionally, we talked about how you can set them up. Please give us your feedback and comments, and don’t hesitate to ask any questions about this useful network security solution. Good luck!
