{{Short description|Firewall management software}} {{technical|date=January 2019}} {{Lowercase title}}{{distinguish|Firewall (disambiguation){{!}}Firewalled}} {{Use mdy dates|date=January 2026}} {{Infobox software | name = firewalld | logo = | screenshot = | caption = | collapsible = | author = | developer = Eric Garver, Thomas Woerner, Red Hat, Inc. | released = {{Start date and age|2011|01|03}}<ref>{{cite web|title=firewalld releases|url=https://github.com/firewalld/firewalld/releases|website=github.com repository|access-date=March 29, 2017}}</ref> | latest release version = {{wikidata|property|preferred|references|edit|P348|P548=Q2804309}} | latest release date = {{Start date and age|{{wikidata|qualifier|preferred|single|P348|P548=Q2804309|P577}}}} | latest preview version = | latest preview date = | repo = {{URL|https://github.com/firewalld/firewalld.git}} | programming language = Python | operating system = Linux | platform = Netfilter | size = | language = | genre = | license = GNU General Public License 2 | website = {{URL|https://www.firewalld.org/}} | bodystyle = width:28em; }}
'''firewalld''' is a firewall management tool for Linux operating systems. It provides firewall features by acting as a front-end for the Linux kernel's netfilter framework. firewalld's current default backend is nftables. Prior to v0.6.0, iptables was the default backend.<ref>{{cite web|url=https://github.com/firewalld/firewalld/releases/tag/v0.6.0|title=Release firewalld-0.6.0 · firewalld/firewalld|website=Firewalld github|access-date=June 12, 2019}}</ref> Through its abstractions, firewalld acts as an alternative to nft and iptables command line programs. The name ''firewalld'' adheres to the Unix convention of naming system daemons by appending the letter "d".<ref>{{cite book|last1=Kerrisk|first1=Michael|title=The Linux Programming Interface|url=https://archive.org/details/linuxprogramming00kerr|url-access=limited|date=2010|publisher=No Starch|location=San Francisco, California|isbn=9781593272203|page=[https://archive.org/details/linuxprogramming00kerr/page/n811 768]}}<!--|access-date=9 February 2016--></ref>
firewalld is written in Python. It was intended to be ported to C++, but the porting project was abandoned in January 2015.<ref>{{cite web|title=firewalld development page|url=https://www.firewalld.org/development/|website=firewalld project website|access-date=February 9, 2016|archive-url=https://web.archive.org/web/20160203173005/https://www.firewalld.org/development/|archive-date=February 3, 2016|url-status=dead}}</ref>
==Features== firewalld supports both IPv4 and IPv6 networks and can administer separate ''firewall zones'' with varying degrees of trust as defined in ''zone profiles''. Administrators can configure Network Manager to automatically switch zone profiles based on known Wi-Fi (wireless) and Ethernet (wired) networks, but firewalld cannot do this on its own.<ref>{{cite web|title= FirewallD|url= https://fedoraproject.org/wiki/FirewallD|website= Fedora community wiki|access-date= February 9, 2016}}</ref>
Services and applications can use the D-Bus interface to query and configure the firewall.<ref name="firewalldhomepage">{{cite web|title= firewalld project home page|url= https://www.firewalld.org/|website= firewalld project website|access-date= February 9, 2016}}</ref> firewalld supports timed rules, meaning the number of connections (or "hits") to a service can be limited globally. There is no support for hit-counting and subsequent connection rejection per source IP; a common technique deployed to limit the impact of brute-force hacking and distributed denial-of-service attacks.<ref name="firewalldvsufw">{{cite web|last1= Aleksandersen|first1= Daniel|title= Comparing and contrasting Uncomplicated Firewall and FirewallD|url= https://www.slightfuture.com/technote/ufw-vs-firewalld|website= Slight Future|date= February 9, 2016|access-date= February 9, 2016|archive-date= January 7, 2017|archive-url= https://web.archive.org/web/20170107005602/https://www.slightfuture.com/technote/ufw-vs-firewalld|url-status= dead}}</ref>
firewalld's command syntax is similar to but more verbose than other iptables front-ends like Ubuntu's Uncomplicated Firewall (ufw).<ref name="firewalldvsufw" /> The command-line interface allows managing firewall rulesets for protocol, ports, source and destination; or predefined services by name.
Services are defined as XML files containing port- and protocol-mappings, and optionally extra information like specifying subnets and listing required Kernel helper modules.<ref> {{cite web |title= firewalld service configuration files |url= https://twoerner.fedorapeople.org/firewalld/doc/firewalld.service.html |website= Thomas Woerner's space on Fedora People |access-date= February 9, 2016 }} </ref> The syntax resembles that of systemd's service files. A simple service file for a web server listening on TCP port 443 might look like this:
<syntaxhighlight lang="xml"> <?xml version="1.0" encoding="utf-8"?> <service> <short>Web Server</short> <description>Public web host over HTTPS.</description> <port port="443" protocol="tcp" /> </service> </syntaxhighlight>
firewalld v0.9.0 added native support for forward and output forwarding via policy objects.<ref>{{cite web|title= Policy Objects Introduction|url= https://firewalld.org/2020/09/policy-objects-introduction|website= firewalld blog|date= September 2, 2020|access-date= August 20, 2021}}</ref> By default, firewalld does not block outbound traffic as required by standards such as NIST 800-171 and 800-53.{{cn|date=January 2026}}
==Graphical front-ends (GUIs)== '''firewall-config''' is a graphical front-end that is optionally included with firewalld, with support for most of its features.
'''firewall-applet''' is a small status indicator utility that is optionally included with firewalld. It can provide firewall event log notifications as well as a quick way to open firewall-config. firewall-applet was ported from the GTK+ to the Qt framework in the summer of 2015 following the GNOME Desktop’s deprecation of system tray icons.<ref>{{cite web|last1=Woerner|first1=Thomas|title=On the way to Qt|url=https://www.firewalld.org/2015/06/on-the-way-to-qt|website=firewalld blog|access-date=February 9, 2016|archive-url=https://web.archive.org/web/20160216230645/https://www.firewalld.org/2015/06/on-the-way-to-qt/|archive-date=February 16, 2016|url-status=dead}}</ref>
==Adoption== {{Portal|Free and open-source software|Linux}} firewalld ships by default on the following Linux distributions:<ref name="firewalldhomepage" />
* CentOS 7 and newer * Fedora 18 and newer * OpenSUSE Leap 15 and newer<ref name=SUSE>{{Cite web|url=https://en.opensuse.org/Firewalld|title=Firewalld - openSUSE Wiki}}</ref> * Red Hat Enterprise Linux 7 and newer * SUSE Linux Enterprise 15 and newer<ref name=SUSE></ref> * EndeavourOS Apollo and newer
firewalld is enabled by default in all of these distributions. firewalld is also available as one of many firewall options in the package repository of many other popular distributions such as Debian<ref>{{cite web|title=Package: firewalld|url=https://packages.debian.org/stable/firewalld|website=Debian package repository|access-date=February 9, 2016}}</ref> or Ubuntu.
==References== {{reflist}}
==External links== * [https://www.linode.com/docs/guides/introduction-to-firewalld-on-centos/ Firewalld guide (in English)] * [https://puerto53.com/linux/configuracion-firewalld-linux/ Firewalld guide (in Spanish)]
{{Firewall software}}
Category:Command-line software Category:Firewall software Category:Linux security software Category:Linux-only free software Category:Red Hat software