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From: "Ric Messier" <kilroy@WasHere.COM>
To: 'Bgs' <bgs@bgs.hu>, netfilter@lists.netfilter.org
Subject: RE: syn DDoS attack solution
Date: Thu, 31 May 2007 14:08:01 -0600	[thread overview]
Message-ID: <015e01c7a3bf$64fbe7e0$2ef3b7a0$@COM> (raw)
In-Reply-To: <465EF582.4070904@bgs.hu>


Bgs writes:
> 
>   We recently got under a low traffic botnet DDoS attack. All attacker
> nodes opened a single tcp session (just SYN part) and then did nothing.
> This rules out rate limiting solutions and syncookie doesn't help
> either. (Thousands of attacking nodes).
> 

This is simply a SYN flood attack. It may or may not be a botnet (though
saying botnet makes it sound sexier :-) ). A decent SYN flood attack tool
would randomize the source address anyway. 

You should try reading the following as a starting point:

http://www.securityfocus.com/infocus/1729

Your second suggestion has been implemented in the TCP/IP stack forever. The
article above gives guidance on how to tune it in a Linux implementation.

Ric



  parent reply	other threads:[~2007-05-31 20:08 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 [this message]
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
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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