descriptionferm is a tool to maintain complex firewalls, without having the trouble to rewrite the complex rules over and over again.
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last changeTue, 18 Apr 2017 14:08:39 +0000 (18 16:08 +0200)
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        Max Kellermann <>
        Auke Kok <>


ferm is a frontend for iptables. It reads the rules from a structured
configuration file and calls iptables(8) to insert them into the
running kernel.

ferm's goal is to make firewall rules easy to write and easy to
read. It tries to reduce the tedious task of writing down rules, thus
enabling the firewall administrator to spend more time on developing
good rules than the proper implementation of the rule.

To achieve this, ferm uses a simple but powerful configuration
language, which allows variables, functions, arrays, blocks. It also
allows you to include other files, allowing you to create libraries of
commonly used structures and functions.

ferm, pronounced "firm", stands for "For Easy Rule Making".

Installing ferm

  make install

The package does not need to be compiled, just make sure you have perl
(which is present in any base linux system) and iptables (including
iptables-save and iptables-restore), and the a kernel supporting

Run the make install install script as root to install the package in
it's best location, so it can be reached from the command line when
called. The manual page will also be installed.

That's all!

Uninstalling ferm

  make uninstall

Ferm can now be quickly removed from the system by issuing a "make
uninstall" command (as root, of course). This will not remove any
configuration files of course!

Getting started

The ferm(1) manpage provides extensive documentation about the ferm
syntax.  To get started, try one of the example files, and modify it
for your needs.

If your machine is already firewalled and you wish to switch to ferm,
the "import-ferm" script comes handy.  It converts the current
firewall rules to a ferm configuration file:

  import-ferm >/etc/ferm/ferm.conf

After that, let ferm install the new ruleset:

  ferm /etc/ferm/ferm.conf

Be careful, don't lock youself out of remote machines!  Use the
interactive mode (--interactive, -i) often!
11 days ago Max KellermannMerge branch 'fix/synproxy' of git:// master
11 days ago Max Kellermannincrement version number to 2.4.1
2017-04-14 Apollon OikonomopoulosFix SYNPROXY timestamp option
2017-04-02 Max Kellermannrelease v2.4
2017-03-29 Max Kellermannimport-ferm: translate "-f" to "fragment"
2017-03-22 Max Kellermann"@preserve" preserves existing chains
2017-03-22 Max Kellermannsort domains and tables in --fast output
2017-03-14 Sam MorrisExtend cgroup match to parse major:minor classification id
2017-03-14 Sam MorrisAdd cgroup match
2017-01-16 Max Kellermannsupport recent/reap
2017-01-16 Max Kellermannsupport recent/mask
2017-01-16 Max Kellermannincrement version number to 2.3.2
2017-01-05 Max Kellermannrelease v2.3.1
2017-01-05 Max Kellermannupdate copyright year to 2017
2017-01-05 Max Kellermanndoc: fix netmask example
2016-10-20 Max Kellermannvarious extension updates
13 months ago v2.3 release v2.3
3 years ago v2.2
4 years ago v2.1.2
4 years ago v2.1.1
5 years ago v2.1
6 years ago v2.0.9
6 years ago v2.0.8
7 years ago v2.0.7
7 years ago v2.0.6
8 years ago v2.0.5
8 years ago v2.0.4
8 years ago v2.0.3
8 years ago v2.0.2
8 years ago v2.0.1
8 years ago v2.0
8 years ago v1.3.5
11 days ago master
8 years ago ferm-1.3.x
9 years ago ferm-1.2.x
10 years ago ferm-1.0.x