The power and flexibility of Netfilter is implemented through the iptables interface. This command line tool is similar in syntax to its predecessor, ipchains; however, iptables uses the Netfilter subsystem to enhance network connection, inspection, and processing; whereas ipchains used intricate rule sets for filtering source and destination paths, as well as connection ports for both. iptables features advanced logging, pre- and post-routing actions, network address translation, and port forwarding all in one command line interface.

This section provides an overview of iptables. For more detailed information about iptables, refer to the Red Hat Enterprise Linux Reference Guide.