Shorewall (lite version), a high-level tool for configuring Netfilter

 Shorewall allows you to describe your firewall/gateway requirements using
 entries in a set of configuration files. It reads those configuration files
 and, with the help of the iptables utility, configures Netfilter to match your
 requirements.
 .
 Shorewall supports a wide range of router/firewall/gateway applications,
 traffic shaping and almost every type of VPN.
 .
 The shorewall-lite package is designed to allow you to maintain all Shorewall
 configuration information on a single system within your network.