The puppetlabs/firewall module is one of the supported modules from Puppet Labs. This means that if you run Puppet Enterprise, you can officially get support on the module on operating systems it will currently run on. At present, this includes Linux distributions. For this reason, this module is one of the best examples of modules available.

The module happens to also be one of the older ones. The current incarnation of this module dates back to early 2011. It also contains the code from an earlier iptables module that dates all the way back to 2007.

The module manages firewall rules on your host. In its current form, it can manage iptables firewalls for IPv4 and IPv6 as well as ebtables for Ethernet bridging and filtering support. In this chapter, we'll cover the iptables IPv4 aspects of the module, although the concepts will apply to all of the other types as well.

Iptables is the primary firewall interface on Linux hosts since kernel Version 2.4. It will...