NARC (Netfilter Automatic Rules Configurator) is a free firewalling package for Netfilter/Iptables, released under the BSD license. It attempts to simplify the setup of a firewall (stateful packet filter) via the iptables tools. It is a bash shellscript that generates (hopefully) sensible and secure rules for Netfilter based on a simple configuration file. It features quick setup via a simple configuration file, connection tracking (and fragmentation reassembly), customized logging, probe detection (TCP & UDP), and much more.
