From mboxrd@z Thu Jan  1 00:00:00 1970
From: Pascal Hambourg <pascal.mail@plouf.fr.eu.org>
Subject: Re: FORWARD packet problem
Date: Wed, 19 Jul 2006 21:09:57 +0200
Message-ID: <44BE8385.4080509@plouf.fr.eu.org>
References: <44BE4BCE.8060509@darkstar.nom.za>
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To: netfilter <netfilter@lists.netfilter.org>

Hello,

Paulo Andre a =E9crit :
> I have a multiple isp fw
> eth0 =3D int
> eth1 =3D default isp
> eth2 =3D sec isp
>=20
> when I try and make a connection to and internal server via the eth2 ,=20
> the packet appears on the PREROUTING table, and then not on FORWARD ,=20
> anyone have any ideas?

I guess there is a default route via eth1.
If so, first check that /proc/sys/net/ipv4/conf/eth2/rp_filter=3D0 else=20
the input routing, which takes place between PREROUTING and INPUT or=20
FORWARD, may drop incoming IP packets on eth2 whose source address is=20
not routed out via eth2 as a protection against IP spoofing.