documentation_complete: true

title: 'iptables and ip6tables'

description: |-
    A host-based firewall called <tt>netfilter</tt> is included as
    part of the Linux kernel distributed with the system. It is
    activated by default. This firewall is controlled by the program
    <tt>iptables</tt>, and the entire capability is frequently referred to by
    this name. An analogous program called <tt>ip6tables</tt> handles filtering
    for IPv6.
    <br /><br />
    Unlike TCP Wrappers, which depends on the network server
    program to support and respect the rules written, <tt>netfilter</tt>
    filtering occurs at the kernel level, before a program can even
    process the data from the network packet. As such, any program on
    the system is affected by the rules written.
    <br /><br />
    This section provides basic information about strengthening
    the <tt>iptables</tt> and <tt>ip6tables</tt> configurations included with the system.
    For more complete information that may allow the construction of a
    sophisticated ruleset tailored to your environment, please consult
    the references at the end of this section.
