https://blog.099c.org/tags/pmtu/ Recent content in Pmtu on Apuntes de root Hugo en-US jorti@pm.me (Juan Orti Alcaine) jorti@pm.me (Juan Orti Alcaine) Wed, 19 Nov 2014 00:00:00 +0000 https://blog.099c.org/posts/ipsec-and-pmtu-problems/ Wed, 19 Nov 2014 00:00:00 +0000jorti@pm.me (Juan Orti Alcaine) https://blog.099c.org/posts/ipsec-and-pmtu-problems/ <p>This post has a very good explanation of the problems I&rsquo;ve been suffering with my IPsec tunnels recently:</p> <p><a href="https://www.zeitgeist.se/2013/11/26/mtu-woes-in-ipsec-tunnels-how-to-fix/" title="MTU woes in IPsec tunnels and how you can fix it">MTU woes in IPsec tunnels and how you can fix it</a></p> <p>Two things have fixed my stalled transmissions over IPsec tunnels:</p> <ol> <li>Clamping the MSS of the IPsec connections to 1280</li> <li>Setting the sysctl <code>net.ipv4.tcp_mtu_probing=1</code></li> </ol> <p>As seen in <a href="https://www.mail-archive.com/ubuntu-devel-discuss@lists.ubuntu.com/msg13065.html">this post</a>, the values of <code>net.ipv4.tcp_mtu_probing</code> are:</p>