[Olsr-users] Too big packets | > 1420 Bytes!

[Michael Rack]

All right! That figures :)

So i try to adjust the vpn-interface mtu settings. I hope OLSR splits 
messages, that gets bigger then the maximum mtu / mss.

Currently i use OLSR v0.6.2.

> DebugLevel      0
> IpVersion       4
> FIBMetric       "flat"
> ClearScreen     yes
>
> RtTable 100
> RtTableDefault 253
>
> AllowNoInt      yes
> TosValue        16
>
> Willingness             3
> LinkQualityLevel        2
> LinkQualityAlgorithm    "etx_ff"
>
> UseHysteresis   no
> Pollrate        0.05
> NicChgsPollInt  3.0
>
> TcRedundancy    2
> MprCoverage     1
>
> InterfaceDefaults
> {
>   ...
> }

Liebe Grüße aus Freilassing,

Michael Rack
RSM Freilassing
-- 
RSM Freilassing                 Tel.: +49 8654 607110
Nocksteinstr. 13                Fax.: +49 8654 670438
D-83395 Freilassing            www.rsm-freilassing.de

Am 12.08.2012 01:09, schrieb Song Gao:
> Hey Michael,
>
> I am probably not the best person to answer this but from my 
> understanding, OLSRd uses MTU of the interface to decide packet size. 
> The interface created by VPN tunnel should be setting proper MTU.
>
> Could you post your OLSRd config file as well as the version of OLSRd 
> you are using?
>
>
> Kind regards,
> -- 
> Song Gao
> https://profiles.google.com/song.gao.beta/about
>
>
>
> On Sat, Aug 11, 2012 at 3:49 PM, Michael Rack 
> <(spam-protected) 
> <mailto:(spam-protected)>> wrote:
>
>     Hi OLSR-Users!
>
>     I have a VPN-Tunnel that runs over a PPPoE-Link, so i have only
>     1492 Bytes available. The VPN-Tunnel is established via UDP, so i
>     have 8 Bytes (MAC), and 12 Bytes (UDP) overhead. So the remaining
>     MTU is 1472 Bytes for the inner Layer-2.
>
>     So there are 1452 Bytes left for OLSR.
>
>     But OLSR currently send out packets with more then 1452 Bytes, so
>     the VPN-Tunnel goes down and automatically get reestablished.
>
>         Aug 11 21:18:50 vtund[6598]: Session
>         neubichl-dsl-backup[79.192.xxx.xxx:46105] opened
>         Aug 11 21:18:50 vtund[6598]: UDP connection initialized
>         Aug 11 21:19:29 vtund[6598]: Message too long (90)
>         Aug 11 21:19:29 vtund[6598]: Session neubichl-dsl-backup closed
>
>
>     currently i drop packages over 1420 bytes that are passing the
>     DSL-Interface:
>
>         iptables -A OUTPUT -o tap107 -m length --length 1420: -j DROP
>
>
>     since that, the VPN-Tunnel is stable.
>
>         ~ # ip route show table olsr-network | wc -l
>         84
>
>
>     currently there are 84 routes spreaded over the whole network via
>     OLSR. That can not result in a so high package size? How can i
>     reduce the packet-size, or what have to be done, so olsr does not
>     eat up more then 1400 Bytes?
>
>
>     Liebe Grüße aus Freilassing,
>
>     Michael Rack
>     RSM Freilassing
>     -- 
>     RSM Freilassing                 Tel.: +49 8654 607110
>     <tel:%2B49%208654%20607110>
>     Nocksteinstr. 13                Fax.: +49 8654 670438
>     <tel:%2B49%208654%20670438>
>     D-83395 Freilassing www.rsm-freilassing.de
>     <http://www.rsm-freilassing.de>
>
>
>     -- 
>     Olsr-users mailing list
>     (spam-protected) <mailto:(spam-protected)>
>     https://lists.olsr.org/mailman/listinfo/olsr-users
>
>

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