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From: Pascal Hambourg <pascal.mail@plouf.fr.eu.org>
To: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Cc: Jan Engelhardt <jengelh@medozas.de>,
	netfilter@vger.kernel.org, "Dennis J." <dennisml@conversis.de>,
	pablo@netfilter.org
Subject: Re: Synflood filtering and Conntrack
Date: Fri, 30 Jul 2010 01:19:56 +0200	[thread overview]
Message-ID: <4C520C9C.7090909@plouf.fr.eu.org> (raw)
In-Reply-To: <alpine.DEB.2.00.1007291723040.32027@blackhole.kfki.hu>

Jozsef Kadlecsik a écrit :
> 
> I don't see why it looks soo complicated: of course, a ct entry is created 
> by conntrack whenever a new connection is detected. And of course the 
> entry is destroyed if the packet, which triggered to create the new entry,
> is dropped by a rule. Why should the conntrack entry be kept, if the 
> connection is not allowed by the rules?
> 
> The new ct entries are kept in the unconfirmed list and only added to the 
> conntrack hash iff the entry will be confirmed, that is the entry-creating 
> packet won't be dropped by a rule.

Thanks for this explanation. Just one more clarification, please : is
the conntrack entry destroyed also if the packet which triggered its
creation is dropped by something else than an iptables rule, such as
routing decision, TTL exceeded, conflict with an existing NAT mapping ?



  parent reply	other threads:[~2010-07-29 23:19 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-07-27 22:29 Synflood filtering and Conntrack Dennis J.
2010-07-28  5:24 ` Mart Frauenlob
2010-07-28  6:11   ` Jan Engelhardt
2010-07-28 13:30     ` Pascal Hambourg
2010-07-28 14:10       ` Jan Engelhardt
2010-07-28 14:27         ` Pascal Hambourg
2010-07-29 11:11     ` Mart Frauenlob
2010-07-29 11:21       ` Jan Engelhardt
2010-07-29 11:31         ` Mart Frauenlob
2010-07-29 12:34           ` Pascal Hambourg
2010-07-29 12:49             ` Jan Engelhardt
2010-07-29 13:16               ` Pascal Hambourg
2010-07-29 15:50               ` Jozsef Kadlecsik
2010-07-29 17:14                 ` Gáspár Lajos
2010-07-29 17:52                   ` Jozsef Kadlecsik
2010-07-29 22:18                 ` Mart Frauenlob
2010-07-29 23:19                 ` Pascal Hambourg [this message]
2010-07-30 10:32                   ` Jozsef Kadlecsik

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