<HTML ><HEAD ><TITLE >General kernel config considerations for PPP</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.76b+ "><LINK REL="HOME" TITLE="Linux PPP HOWTO" HREF="index.html"><LINK REL="UP" TITLE="Configuring your Linux Kernel" HREF="kernel-configuration.html"><LINK REL="PREVIOUS" TITLE="Note on PPP-2.x and /proc/net/dev" HREF="x676.html"><LINK REL="NEXT" TITLE="Getting the Information you need about the PPP server" HREF="server-info.html"></HEAD ><BODY CLASS="SECT1" BGCOLOR="#FFFFFF" TEXT="#000000" LINK="#0000FF" VLINK="#840084" ALINK="#0000FF" ><DIV CLASS="NAVHEADER" ><TABLE SUMMARY="Header navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TH COLSPAN="3" ALIGN="center" ><A HREF="http://www.linuxports.com/howto/ppp" TARGET="_top" >Linux PPP HOWTO</A ></TH ></TR ><TR ><TD WIDTH="10%" ALIGN="left" VALIGN="bottom" ><A HREF="x676.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" >Chapter 10. Configuring your Linux Kernel</TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="server-info.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><DIV CLASS="SECT1" ><H1 CLASS="SECT1" ><A NAME="AEN686">10.6. General kernel config considerations for PPP</H1 ><P >If you are setting up your Linux PC as a PPP server, you must compile in IP forwarding support. This is also necessary if you want to use Linux to link to LANs together or your LAN to the Internet.</P ><P >If you are linking a LAN to the Internet (or linking together two LANs), you should be concerned about security. Adding support for IP fire walls to the kernel is probably a MUST!</P ><P >You will also need this if you want to use IP masquerade to connect a LAN that uses any of the above mentioned 'unconnected' IP network numbers.</P ><P >To enable IP Masquerade and IP fire walling, you <EM >MUST</EM > answer yes to the first question in the <TT CLASS="LITERAL" >make config</TT > process:- <TABLE BORDER="0" BGCOLOR="#E0E0E0" WIDTH="100%" ><TR ><TD ><FONT COLOR="#000000" ><PRE CLASS="PROGRAMLISTING" >Prompt for development and/or incomplete code/drivers (CONFIG_EXPERIMENTAL)?</PRE ></FONT ></TD ></TR ></TABLE > </P ><P >Whilst this may sound a bit off-putting to new users, many users are actively using the IP Masquerade and IP fire walling features of the Linux 2.0.x or 2.2.x kernels with no problems.</P ><P >Once you have installed and rebooted your new kernel, you can start configuring and testing your PPP link(s).</P ></DIV ><DIV CLASS="NAVFOOTER" ><HR ALIGN="LEFT" WIDTH="100%"><TABLE SUMMARY="Footer navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" ><A HREF="x676.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="index.html" ACCESSKEY="H" >Home</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><A HREF="server-info.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >Note on PPP-2.x and <TT CLASS="LITERAL" >/proc/net/dev</TT ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="kernel-configuration.html" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >Getting the Information you need about the PPP server</TD ></TR ></TABLE ></DIV ></BODY ></HTML >