I also tested ping with -M option, from B1 to GW1:<br>ping -M do -s 1448 192.168.20.4<br><br>It works up to 1448 bytes, then starting from 1549 I receive the error <br>&quot;From 192.168.100.2 icmp_seq=1 Frag needed and DF set (mtu = 1476)&quot;<br>
<br>And my bat0 configuration is:<br><br>bat0: &lt;BROADCAST,MULTICAST,UP,LOWER_UP&gt; mtu 1476 qdisc pfifo_fast state UNKNOWN qlen 1000<br><br><br>andrea<br><br><div class="gmail_quote">On Tue, Oct 6, 2009 at 11:43 AM, Sven Eckelmann <span dir="ltr">&lt;<a href="mailto:sven.eckelmann@gmx.de">sven.eckelmann@gmx.de</a>&gt;</span> wrote:<br>
<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"><div class="im">a wrote:<br>
&gt; It is correct. I&#39;m using openwrt and, at the moment, without -M option.<br>
&gt; 1500byte packets work, with fragmentation.<br>
&gt; However, my TCP packets are small (about 60bytes). I have verified TCPDump<br>
&gt; file and packets arrive. It seems that the Linux IP stack does not forward<br>
&gt; them to the application.<br>
&gt; Moreover, if I disable batman on B1-GW1 link, it works<br>
</div>So it would be a good idea to do what Marek said. Give him a dump with `batctl<br>
td` on the gateway and if I could add something: complete tcpdump of both ends<br>
so we can see what packets receive on both sites.<br>
<br>
Best regards,<br>
<font color="#888888">        Sven<br>
</font></blockquote></div><br>