Marcus Moeller wrote on Mon, 9 Feb 2009 14:23:02 +0100:
Google for that as a string
iptables -A FORWARD -i eth0 -o eth0
and you will see quite a few hits, also in German. For instance http://www.linuxforen.de/forums/showthread.php?t=81200
It seems you are either doing something wrong or testing in the wrong way. (I'm not very familiar with forwarding rules.)
Kai