Re: Ugly problem with ebtables

[Pascal Hambourg <pascal.mail@plouf.fr.eu.org>]

Hello,

Juan Antonio Rodriguez Moreno a écrit :
> 
> I have a linux bridged machine, with eth1 and eth2 port on br0. I'm using
> ebtables to up smtp traffic on routing process and iptables to mark it. I
> route this traffic over openvpn tunnel tun0.
> 
> That's all right but when IP fragment a packet and send the former frame
> without the PUSH flag, this frame dissapear.

What your traces shows below is not IP fragmentation (which has nothing 
to do with PUSH which is a TCP flag) but TCP segmentation.

> I can see all traffic on the sending point of the tunel, but the frames
> without the PUSH flag set don't arrive on the another side.

IIUC, some packets enter the bridge, are routed through the tunnel and 
don't arrive at the other end. What makes you think that ebtables is 
involved ?

Couldn't it be an MTU problem in the tunnel ? AFAIK, when TCP transmits 
a message which must be segmented, it sends maximum-size segments 
without the PUSH flag and a last smaller segment with the PUSH flag set 
containing the remaining data.