<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML ><HEAD ><TITLE >Support in kernel (ESP and AH)</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.7"><LINK REL="HOME" TITLE="Linux IPv6 HOWTO (en)" HREF="index.html"><LINK REL="UP" TITLE="Encryption and Authentication" HREF="chapter-encryption-authentication.html"><LINK REL="PREVIOUS" TITLE="Modes of using encryption and authentication" HREF="x2360.html"><LINK REL="NEXT" TITLE="Automatic key exchange (IKE)" HREF="x2381.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 IPv6 HOWTO (en)</TH ></TR ><TR ><TD WIDTH="10%" ALIGN="left" VALIGN="bottom" ><A HREF="x2360.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" >Chapter 19. Encryption and Authentication</TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="x2381.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><DIV CLASS="SECT1" ><H1 CLASS="SECT1" ><A NAME="AEN2371" ></A >19.2. Support in kernel (ESP and AH)</H1 ><DIV CLASS="SECT2" ><H2 CLASS="SECT2" ><A NAME="AEN2373" ></A >19.2.1. Support in vanilla Linux kernel 2.4.x</H2 ><P >At the time of writing missing in vanilla up to 2.4.28. There was an issue about keeping the Linux kernel source free of export/import-control-laws regarding encryption code. This is also one case why <A HREF="http://www.freeswan.org/" TARGET="_top" >FreeS/WAN project</A > wasn't included in vanilla source. Perhaps a backport from 2.6.x will be done in the future.</P ></DIV ><DIV CLASS="SECT2" ><H2 CLASS="SECT2" ><A NAME="AEN2377" ></A >19.2.2. Support in vanilla Linux kernel 2.6.x</H2 ><P >Current versions (as time of writing 2.6.9 and upper) support native IPsec for IPv4 and IPv6.</P ><P >Implementation was helped by the USAGI project.</P ></DIV ></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="x2360.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="x2381.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >Modes of using encryption and authentication</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="chapter-encryption-authentication.html" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >Automatic key exchange (IKE)</TD ></TR ></TABLE ></DIV ></BODY ></HTML >