From: Pablo Neira Ayuso <pablo@netfilter.org>
To: Alessandro Vesely <vesely@tana.it>
Cc: netfilter@vger.kernel.org, support@iptables.info,
Jan Engelhardt <jengelh@medozas.de>
Subject: Re: Best way to kill a live TCP connection?
Date: Wed, 12 Jan 2011 01:20:29 +0100 [thread overview]
Message-ID: <4D2CF3CD.1030704@netfilter.org> (raw)
In-Reply-To: <4D2C8374.70408@tana.it>
On 11/01/11 17:21, Alessandro Vesely wrote:
> On 11/Jan/11 15:41, Jan Engelhardt wrote:
>> On Tuesday 2011-01-11 13:35, Alessandro Vesely wrote:
>>
>>> Hi all,
>>> this is clearly an overworked topic. However, I haven't been able to
>>> find definitive info about it. Please help providing more insight.
>>> In particular, if it is possible/convenient to design an RST injector
>>> and how to attach it to iptables?
>>
>> If you use a ruleset that emits RST for NEW connections that are picked
>> up rather than SYN-new,
>>
>> -m conntrack --ctstate NEW -p tcp ! --syn --dport 22 -j REJECT
>> --reject-with tcp-reset
>>
>> .. makes it possible to RST-kill connections using `conntrack -D`.
>
> That's the most elegant method I've seen thus far. Thanks a lot!
>
> A generic rule like that (i.e. without --dport) is mentioned in the
> tutorial http://www.iptables.info/en/iptables-problems.html#NEWNOTSYN
> but I never realized it can be used this way. (I CC this there.)
I'll try to add this to the conntrack-tools manual, it's indeed good.
prev parent reply other threads:[~2011-01-12 0:20 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-01-11 12:35 Best way to kill a live TCP connection? Alessandro Vesely
2011-01-11 14:41 ` Jan Engelhardt
2011-01-11 16:21 ` Alessandro Vesely
2011-01-11 17:39 ` Pascal Hambourg
2011-01-11 21:10 ` Grant Taylor
2011-01-11 22:31 ` Jan Engelhardt
2011-01-12 8:52 ` Alessandro Vesely
2011-01-18 17:50 ` Alessandro Vesely
2011-01-18 18:45 ` Gáspár Lajos
2011-01-19 13:32 ` Alessandro Vesely
2011-01-12 0:20 ` Pablo Neira Ayuso
2011-01-12 0:20 ` Pablo Neira Ayuso [this message]
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