<HTML ><HEAD ><TITLE >Userland tunnels</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.7"><LINK REL="HOME" TITLE="Linux Advanced Routing & Traffic Control HOWTO" HREF="index.html"><LINK REL="UP" TITLE="GRE and other tunnels" HREF="lartc.tunnel.html"><LINK REL="PREVIOUS" TITLE="GRE tunneling" HREF="lartc.tunnel.gre.html"><LINK REL="NEXT" TITLE="IPv6 tunneling with Cisco and/or 6bone" HREF="lartc.ipv6-tunnel.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" >Linux Advanced Routing & Traffic Control HOWTO</TH ></TR ><TR ><TD WIDTH="10%" ALIGN="left" VALIGN="bottom" ><A HREF="lartc.tunnel.gre.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" >Chapter 5. GRE and other tunnels</TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="lartc.ipv6-tunnel.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><DIV CLASS="SECT1" ><H1 CLASS="SECT1" ><A NAME="LARTC.TUNNEL.USERLAND" ></A >5.4. Userland tunnels</H1 ><P >There are literally dozens of implementations of tunneling outside the kernel. Best known are of course PPP and PPTP, but there are lots more (some proprietary, some secure, some that don't even use IP) and that is really beyond the scope of this HOWTO.</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="lartc.tunnel.gre.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="lartc.ipv6-tunnel.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >GRE tunneling</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="lartc.tunnel.html" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >IPv6 tunneling with Cisco and/or 6bone</TD ></TR ></TABLE ></DIV ></BODY ></HTML >