Workshop: Lock down your Linux system with Firewalld and OpenSnitch
Double Protection
© Lead Image courtesy of Sofia Tolstaya, the author's 10-year-old daughter
For maximum security, you'd better watch traffic in both directions. This hands-on workshop takes you through the steps of setting up firewalls for outgoing as well as incoming traffic.
Linux has a great selection of firewalls for securing stand-alone computers or whole networks. Small LANs usually depend on small routers for security. But what if your Linux machine is exposed on the network and you don't have control over the upstream router or gateway? What if you're working behind one of the millions of smaller routers with out-of-date firmware or missing security patches?
If you're really serious about building a perfectly secure, network-attached Linux workstation, you'll need to fortify the system from two directions: with a host-based firewall for managing incoming connections and with a per-application firewall for controlling outbound traffic. This hands-on workshop will show you how to fortify your system using Firewalld and the OpenSnitch application firewall.
Limiting the Incoming Flow
Network security starts with limiting access to your host from the outer world. One of the most advanced and popular tools for limiting incoming traffic is Firewalld [1], a modern and flexible firewall that replaced the legacy Iptables software a few years ago. Firewalld was introduced as a default network security solution in Fedora 18 and RHEL 7, and consequently, in CentOS 7 as well. The Firewalld firewall is now included in many other mainstream Linux distributions, such as openSUSE and Arch.
[...]
Buy this article as PDF
(incl. VAT)
Buy Linux Magazine
US / Canada
UK / Australia
Subscribe to our Linux Newsletters
Find Linux and Open Source Jobs
Subscribe to our ADMIN Newsletters
Support Our Work
Linux Magazine content is made possible with support from readers like you. Please consider contributing when you’ve found an article to be beneficial.
News
-
Akamai Will Host kernel.org
The organization dedicated to cloud-based solutions has agreed to host kernel.org to deliver long-term stability for the development team.
-
Linux Kernel 6.14 Released
The latest Linux kernel has arrived with extra Rust support and more.
-
EndeavorOS Mercury Neo Available
A new release from the EndeavorOS team ships with Plasma 6.3 and other goodies.
-
Fedora 42 Beta Has Arrived
The Fedora Project has announced the availability of the first beta release for version 42 of the open-source distribution.
-
Dash to Panel Maintainer Quits
Charles Gagnon has stepped away as maintainer of the popular Dash to Panel Gnome extension.
-
CIQ Releases Security-Hardened Version of Rocky Linux
If you're looking for an enterprise-grade Linux distribution that is hardened for business use, there's a new version of Rocky Linux that's sure to make you and your company happy.
-
Gnome’s Dash to Panel Extension Gets a Massive Update
If you're a fan of the Gnome Dash to Panel extension, you'll be thrilled to hear that a new version has been released with a dock mode.
-
Blender App Makes it to the Big Screen
The animated film "Flow" won the Oscar for Best Animated Feature at the 97th Academy Awards held on March 2, 2025 and Blender was a part of it.
-
Linux Mint Retools the Cinnamon App Launcher
The developers of Linux Mint are working on an improved Cinnamon App Launcher with a better, more accessible UI.
-
New Linux Tool for Security Issues
Seal Security is launching a new solution to automate fixing Linux vulnerabilities.