Using fail2ban with iptables instead of firewalld

In the previous post I wrote about the minor configuration changes needed to get fail2ban to actually do something.

I have been working primarily with CentOS 7 and have been using iptables instead of firewalld. Normally, fail2ban works with iptables by default. However, installing fail2ban on CentOS 7 also installs fail2ban-firewalld — which changes that default. Even with a properly configured fail2ban jail, you will not see the expected results. fail2ban will log events as expected, but no traffic will actually be banned.

The fail2ban-firewalld package places a file in /etc/fail2ban/jail.d/00-firewalld.conf. It overrides the default banaction (iptables) and sets it to firewallcmd-ipset.

The top of the 00-firewalld.conf file says:

You can remove this package (along with the empty fail2ban meta-package) if you do not use firewalld

When I tried removing fail2ban-firewalld, it removed fail2ban as a dependency. I have a feeling the referenced fail2ban meta-package may have something to so with that.

I have not yet investigated the meta-package and de-coupling fail2ban-firewalld from fail2ban (see Update below). My solution, for now, has been to move 00-firewalld.conf and restart fail2ban:

$ sudo mv /etc/fail2ban/jail.d/00-firewalld.conf /etc/fail2ban/jail.d/00-firewalld.disabled
$ sudo systemctl restart fail2ban

The default banaction defined in jail.conf is no longer overridden and performs as expected:
banaction = iptables-multiport

Update
According to Fail2ban with FirewallD, The fail2ban package itself is a meta-package that contains several other packages, including fail2ban-firewalld and fail2ban-server. Removing the meta-package will not remove fail2ban-server.

If you’ve already moved 00-firewalld.conf to 00-firewalld.disabled, you’ll get a warning:
warning: file /etc/fail2ban/jail.d/00-firewalld.conf: remove failed: No such file or directory

You can ignore the warning, or remove 00-firewalld.disabled.

4 thoughts on “Using fail2ban with iptables instead of firewalld”

  1. hello,
    thanks for this idea. To watch for ssh attempts I need to install fail2ban-server only. Thanks again!
    a.

  2. It’s worth noting that just installing fail2ban-server will result in some missing default fail2ban configs being made, such as /etc/fail2ban/action.d/sendmail-common.conf

  3. Hi !
    While I have found a lot of articles on using iptables with failban to achieve banning, there is little or no information on using firewalld with fail2ban and on related configuration issues.

    Would be great if you could shed some light on this newer method like what configuration changes are needed to be made in some custom conf file to achieve the correct banning.

    Thanks

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