Jack Wallen/ZDNETZDNET’s key takeaways
- The default Fedora/KDE firewall GUI can be daunting.
- An alternative is Plasma Firewall, which is simpler.
- This firewall GUI is free to install and use.
Firewalls are a necessity. Even if you’re using the Linux operating system as your desktop, you will benefit from having a firewall up and running.
Also: Yes, you need a firewall on Linux — here’s why and which to use
But not all firewalls are created equal. Take, for instance, the Uncomplicated Firewall (UFW) system, the default for Ubuntu-based distributions. Not only is this tool’s command-line version easy to use, but the GUIs are even easier.
Then there’s the Fedora equivalent, firewalld. This firewall is very powerful but not nearly as beginner-friendly as UFW. Even the firewalld GUIs can overwhelm new users. You have to know about zones and other firewall features that you don’t have to bother with when using UFW.
Any time I have to use the Fedora firewalld GUI, I roll my eyes thinking, “Someone needs to make a front end for this that won’t scare off those who are new to Linux.”
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It just so happens that I found such a GUI the other day that makes configuring your firewall on KDE Plasma/Fedora much easier.
The GUI in question is called Plasma Firewall.
What is Plasma Firewall?
Plasma Firewall isn’t a standalone app. Instead, when you install Plasma Firewall, the tool adds a firewall section to the KDE Plasma Settings app.
You can install Plasma Firewall from the default repositories by opening Discover (the KDE app store), searching for Firewall, locating Info Center – Plasma Firewall, and clicking Install.
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Unlike the complex features of the firewalld GUI, all users face with Plasma Firewall are default incoming and outgoing rules and specific rules for particular apps and services.
If you’re unfamiliar with how a firewall works, the fundamentals are simple:
- A packet of data attempts to enter your computer.
- The firewall compares the packet to custom rules. If a rule applies to the packet (such as allowing it in), it is applied; if not, the firewall continues its evaluation.
- If there are no custom rules, the packet is compared to the default input policy, which is either allow, deny, or reject.
- If the default policy is allow, the packet is allowed in; if it’s reject, the packet is denied with a message; if it’s deny, the packet is denied with no message.
That’s the basic gist of a firewall and all you really need to know at first.
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The default incoming policy of nearly all firewalls is Reject, which Plasma Firewall adheres to. So, when a packet comes in, if there’s no rule allowing it through, it is denied.
Using the simplified GUI
Say, however, you want to allow SSH connections into your machine. In that situation, you would create a rule that allows SSH connections. With Plasma Firewall, open the firewall section in KDE System Settings (you might need to search for firewall), click Add Rule, select SSH from the dropdown, and click Create. The SSH rule is then created and automatically set to Allow.
Screenshot by Jack Wallen/ZDNETYou can also customize a rule. For example, when you create a new rule, check the Advanced box, which opens the pop-up window for more advanced features.
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In the advanced section, you can customize the source and destination addresses, IP version, protocol, interface, and logging. Keeping with our earlier example, if I wanted to limit SSH connections to my local LAN (which uses a 192.168.1.x IP address scheme), I could open the advanced section and set the following:
- Policy: Allow
- Source: 192.168.1.1/24
- Destination: IP of the machine to connect to
- Port: Both set to 22
- Protocol: TCP
- Interface: Any
Screenshot by Jack Wallen/ZDNETClick Create, and only machines on my LAN can connect to the desktop in question via SSH.
After you’ve created the rule, click the Enabled slider to Off, wait a second, and then click it back to On.
In short, Plasma Firewall is easier to use than the default firewalld GUI, and being built into the Settings app makes managing your system more efficient.
From my perspective, whatever it takes to get people to use their OS’s firewall is a good thing, and if that means installing a sort of dumbed-down version of the primary firewall GUI, then so be it. This particular GUI might not be as powerful as the default, but more people might use it because it’s simple.
And that, my friends, is a good thing.
