From mboxrd@z Thu Jan  1 00:00:00 1970
From: Alexey Kurnosov <akurn@omnisp.ru>
Subject: GRE filter.
Date: Sat, 20 Mar 2004 20:48:49 +0300
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Sorry for my English.

I have Linux as VPN terminator (pptpd). Some computers in LAN should not 
have access to the server (Over GRE). So I just put:

iptables -I INPUT -s 192.168.1.1 -j DROP

And nothing.

I put:
iptables -I PREROUTING -s 192.168.1.1 -p 47 -j LOG
iptables -I PREROUTING -s 192,.168.1.1 -j LOG

and there are no messages from kernel when tunnel is up.

What wrong? Why some IP-level packets travel behind my filter?

--
Best regards.
Alex Kurnosov.