<html xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns="http://www.w3.org/TR/REC-html40">
<head>
<META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=us-ascii">
<meta name=Generator content="Microsoft Word 11 (filtered medium)">
<style>
<!--
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0cm;
margin-bottom:.0001pt;
font-size:12.0pt;
font-family:"Times New Roman";}
a:link, span.MsoHyperlink
{color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{color:purple;
text-decoration:underline;}
span.E-MailFormatvorlage17
{mso-style-type:personal-compose;
font-family:Arial;
color:windowtext;}
@page Section1
{size:595.3pt 841.9pt;
margin:70.85pt 70.85pt 2.0cm 70.85pt;}
div.Section1
{page:Section1;}
-->
</style>
</head>
<body lang=DE link=blue vlink=purple>
<div class=Section1>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>hallo,<br>
<br>
i am using openswan 2.3.0 under suse9.3 (kernel 2.6.10). If i start a
connection from my winxp pro workstation (sp2) via adsl a vpn-connection every
thing works fine until i start a vnc-session. Then the screen is frozen and
nothing works. This is a classical (p)mtu-prohlem as i read but until now i
haven'f found any solution for this problem.<br>
<br>
Here is what i did:<br>
<br>
Under windows xp the largest packet i can ping without defragmentation is 1395
bytes (ping -f -l 1395 xx.xx.xx.xx). The mtu of my linuxbox is 1492 bytes. I am
tuning via iptables the mtu:<br>
<br>
#iptables -A FORWARD -p tcp -m tcp --tcp-flags SYN,RST SYN -j TCPMSS --set-mss
1452<br>
iptables -A FORWARD -p tcp --tcp-flags SYN,RST SYN -j TCPMSS
--clamp-mss-to-pmtu<br>
<br>
none of them fixed the problem.<br>
<br>
During the session setup my linux box writes the following message to the
systemlog:<br>
kernel: pmtu discovery on SA ESP/54c693d0/54a99ca9<br>
<br>
Do you have any suggestions?<br>
<br>
<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><br>
Regards from germany<br>
Frank</span></font><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p></o:p></span></font></p>
</div>
</body>
</html>