Best Opensource Firewall Programs Available In Linux

In this post we will discuss some best and popular opensource firewall tools which are available for Linux system. "A firewall is a very basic and important network security feature that monitors incoming and outgoing network traffic and decides whether to allow or block specific traffic based on a defined set of security rules. Firewall set a barrier between trusted and untrusted network."

There are two types of firewall available in computing world.

1: Hardware Firewall : They are dedicated hardware machines which filter the packets based on defined and configured rules

2: Software Firewall : They are software tools which can be installed with in an operating system and confgiured in terms of rules to blocks or filter network ips

In this post we will talk about software firewall which are opensource and available for Linux systems.


The one of the legacy firewall program for Linux system. iptables is the userspace command line program used to configure the Linux 2.4.x and later packet filtering ruleset. It is targeted towards system administrators. The iptables package also includes ip6tables. ip6tables is used for configuring the IPv6 packet filter. It was initialy released on 1998 and written in C by Rusty Russel.

Dependecies : iptables requires a kernel that features the ip_tables packet filter. This includes all 2.4.x and later kernel releases.

Main Features

1) listing the contents of the packet filter ruleset

2) adding/removing/modifying rules in the packet filter ruleset

3) listing/zeroing per-rule counters of the packet filter ruleset

Download : You can download the package from official repository.


RPM Base Distros

sudo yum install iptables

Debian/Ubuntu Based Distros

sudo apt install iptables

Arch/Manjaro Based Distros

sudo pacman -Syu iptables


Ufw stands for Uncomplicated Firewall, and is program for managing a netfilter firewall. It provides a command line interface and aims to be uncomplicated and easy to use. Its by default installed in all ubuntu operating systems from version 8.


- iptables
- python (2.6+)
- iptables (1.4**)
- gettext
- /proc filesystem support

Main Features

- IPv6 (by default)

- extensible framework

- application integration

- bash completion

- rsyslog support

- python 3.5 support

-systemd support

-log levels


You can download the package from official repository


RPM Base Distros

yum install epel-release
yum update
yum install ufw

Debian Base Distros

by default installed in Ubuntu and some other debian based systems

apt install ufw

Arch Based System

 sudo pacman -Sy ufw

firewalld[ Dynamic Firewall ]

Firewalld is one of the latest and popular firewall program pre installed in Redhat/CentOS/Fedora distros developed by Redhat as a front end tool for Linux kernel's netfilter framework. Firewalld provides a dynamically managed firewall with support for network/firewall zones to define the trust level of network connections or interfaces. Firewalld uses firewall-cmd utility to manage and operate its services. First released on Jan 2011 at Redhat.Inc and written in Python. For more detail you can visit its official website.


- ebtables
- ipset
- iptables
- python-firewall
- bash
- systemd
- pythone-platform

Main Features

- Affect loads in runtime environment. No restart of the service or daemon is needed
- Firewall zones
- IPv4 and IPv6 NAT support
- Simple service, port, protocol, source port, masquerading, port forwarding, icmp filter, rich rule, interface and source address handlig in zones
- Graphical configuration tool using gtk3
- Complete D-Bus API
- Automatic loading of Linux kernel modules
- Rich Language for more flexible and complex rules in zones
- Simple service definition with ports, protocols, source ports, modules (netfilter helpers) and destination address handling
- Many More....


You can download the package from official repository


RPM Base Distros

 yum install firewalld

Arch Base Distros

 pamac build firewalld-git

Deb Base Distros

 apt install firewalld


The most recent and powerful program , nftable is another opensource netfilter tool written in C provided by the as a replacement of ip, ip6, arp, eb tables. It has been available since Linux kernel 3.13 released on 19 January 2014. The software provides a new nft userspace command line tool. nftables reuses the existing Netfilter subsystems such as the existing hook infrastructure, the connection tracking system, NAT, userspace queueing and logging subsystem. how ever the commands for nftables are different but you can use iptables commands in it.


- Linux kernel >= 3.13
- libmnl: the minimalistic Netlink library
- libnftnl: low level netlink userspace library
- nft: command line tool

Main Features

Network-specific VM.
Smaller kernel codebase.
Unified and consistent syntax for every support protocol family.
High performance through maps and concatenations.
Allow monitoring of rule updates.
Move most rule handling to userspace.
No distinction between matches and targets anymore.
Applications can ask the kernel to get a notification when rules are added or removed.


you can download the package from official repository


Deb Base Distros

 apt install nftables

RPM Base Distros

 yum install nftables

Arch Base Distros

 sudo pacman -Syu nftables


There are many other applications available which provided "network traffic filtering" for Linux kernel but no one is better or stable as these ones. However UFW & Firewalld are only the frontend tool for iptables. But comes with ease to configure firewall rules. In other hand , nftables is the upgrade version of iptables which provide more flexibilty , stablility , features with backup compatibilty of iptables. There are many GUI application e.g GUFW, Firewall-Config available which can be used to manage and configure these program in graphical manner. Which one is your faviroute tool to manage firewall services , write down in below comment section.

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