<sect3 id="userppp-nat">

	<title>Using PPP Network Address Translation Capability</title>

	<indexterm><primary>PPP</primary><secondary>NAT</secondary></indexterm>

	<para>PPP has ability to use internal NAT without kernel diverting

	  capabilities. This functionality may be enabled by the following 

	  line in <filename>/etc/ppp/ppp.conf</filename>:</para>

	<programlisting>nat enable yes</programlisting>

	<para>Alternatively, PPP NAT may be enabled by command-line

	  option <literal>-nat</literal>. There is also 

	  <filename>/etc/rc.conf</filename> knob named 

	  <literal>ppp_nat</literal>, which is enabled by default.</para>

	<para>If you use this feature, you may also find useful

	  the following <filename>/etc/ppp/ppp.conf</filename> options

	  to enable incoming connections forwarding:</para>

	<programlisting>nat port tcp 10.0.0.2:ftp ftp

nat port tcp 10.0.0.2:http http</programlisting>

	<para>or don't trust the outside at all</para>

	<programlisting>nat deny_incoming yes</programlisting>

      </sect3>