From: Kerin Millar <kerframil@gmail.com>
To: netfilter@vger.kernel.org
Subject: Re: ICMP packets seeping through a DROP policy - security concern
Date: Mon, 05 Mar 2012 19:51:17 +0000 [thread overview]
Message-ID: <jj35fo$t1p$1@dough.gmane.org> (raw)
In-Reply-To: <20120304172506.2e79468a@mistral.stie>
On 04/03/2012 22:25, jonetsu wrote:
> The setup is:
>
> unit1<--> eth4 unit3 eth1<--> unit2
>
> unit1 is continuously pinging unit2 via unit3. Rules are applied
> on unit3.
In that case, it's the FORWARD chain that matters. The behaviour of
kernel 3.0.0 seems correct; ping continues to work because the ICMP is
subjected to connection tracking and you are allowing
RELATED/ESTABLISHED traffic in the FORWARD chain. To test the INPUT
chain, you should be pinging unit3, not unit2.
Cheers,
--Kerin
next prev parent reply other threads:[~2012-03-05 19:51 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-03-04 22:25 ICMP packets seeping through a DROP policy - security concern jonetsu
2012-03-05 19:51 ` Kerin Millar [this message]
2012-03-07 1:09 ` jonetsu
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