From: Martijn Lievaart <m@rtij.nl>
To: Ric Messier <kilroy@WasHere.COM>
Cc: netfilter@lists.netfilter.org
Subject: Re: syn DDoS attack solution
Date: Fri, 01 Jun 2007 23:34:02 +0200 [thread overview]
Message-ID: <466090CA.2050806@rtij.nl> (raw)
In-Reply-To: <007101c7a45d$bc50e380$34f2aa80$@COM>
Ric Messier wrote:
> Bgs writes:
>
>> Some more info about the attack: All IPs were real IPs otherway the tcp
>> handshake wouldn't have made it. The attacker IPs were also consistent.
>> They also new about the blocked IPs as after a new bunch of blocked IPs
>> we fared OK then they added another bunch new IPs... we played this for
>> quite some time...
>>
>> All connections were in the ESTABLISHED state.
>>
>>
>
> Then your original description was incorrect or at least inadequate. It has
> nothing to do with SYN as originally suggested since an ESTABLISHED
> connection has blown past SYN, through SYN/ACK and by ACK. It has completed
> the TCP handshake, as you note above. A SYN attack/flood would stop after
> sending the initial SYN and leave the connection half-open to exhaust the
> half-open buffers.
>
An connection is in the ESTABLISHED state once a packet has been seen.
So once the SYN is seen, the state is ESTABLISHED.
M4
next prev parent reply other threads:[~2007-06-01 21:34 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-05-31 16:19 syn DDoS attack solution Bgs
2007-05-31 19:57 ` R. DuFresne
2007-06-01 9:45 ` Bgs
2007-05-31 20:08 ` Ric Messier
2007-06-01 1:20 ` Tony.Ho
2007-06-01 9:44 ` Bgs
2007-06-01 15:01 ` Ric Messier
2007-06-01 15:37 ` Bgs
2007-06-02 19:07 ` R. DuFresne
2007-06-04 14:22 ` Ric Messier
2007-06-04 17:24 ` Martin McKeay
2007-06-04 23:16 ` R. DuFresne
2007-06-05 8:29 ` Bgs
2007-06-05 14:16 ` Steven M Campbell
2007-06-05 15:22 ` ..prevention, was: " Arnt Karlsen
[not found] ` <466583F4.8080107@SCampbell.net>
2007-06-05 15:40 ` Steven M Campbell
2007-06-05 18:34 ` Arnt Karlsen
2007-06-07 18:41 ` Martin McKeay
2007-06-08 1:40 ` Arnt Karlsen
2007-06-12 18:10 ` Martin McKeay
2007-06-12 22:44 ` R. DuFresne
2007-06-13 14:24 ` Martin McKeay
2007-06-13 17:26 ` Arnt Karlsen
2007-06-13 17:44 ` Martin McKeay
2007-06-14 19:43 ` R. DuFresne
2007-06-14 20:13 ` supportnew
2007-06-01 21:34 ` Martijn Lievaart [this message]
2007-06-01 21:37 ` Martijn Lievaart
2007-06-01 21:38 ` Ric Messier
2007-06-01 23:09 ` Ethy H. Brito
2007-06-19 18:22 ` R. DuFresne
2007-06-19 22:19 ` Robert Nichols
2007-06-19 23:02 ` Pascal Hambourg
2007-06-21 18:26 ` R. DuFresne
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