From: Olaf van der Spek <olafvdspek@gmail.com>
To: netdev@vger.kernel.org
Subject: Re: Enable syn cookies by default
Date: Wed, 21 Oct 2009 09:17:53 +0200 [thread overview]
Message-ID: <b2cc26e40910210017v3885b18dre5021c8a920f30d7@mail.gmail.com> (raw)
In-Reply-To: <b2cc26e40910150159q68ce555fs4b1683969d939d25@mail.gmail.com>
On Thu, Oct 15, 2009 at 10:59 AM, Olaf van der Spek
<olafvdspek@gmail.com> wrote:
> On Sat, Oct 10, 2009 at 3:01 PM, Olaf van der Spek <olafvdspek@gmail.com> wrote:
>> Hi,
>>
>> I'm forwarding Debian feature request #520668.
>>
>> Could syn cookies be enabled by default?
>>
>> AFAIK syn cookies only get send when the half-open TCP connection
>> queue is full. So stuff like window scaling should work fine in normal
>> situations.
>>
>> Speaking of which:
>> When the half-open TCP connection queue is full and syn cookies are
>> enabled, you get a message like "kernel: possible SYN flooding on port
>> 2710. Sending cookies."
>> However when syn cookies are disabled, you don't get any message (in
>> kern.log), although connections to your server are timing out.
>> Could such a message be added?
>> Maybe with a suggestion to increase the size of that queue or to
>> enable syn cookies.
>>
>> Greetings,
>>
>> Olaf
>>
>> http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=520668
>> http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=520667
>> https://bugs.launchpad.net/ubuntu/+bug/57091
>>
>
> Somebody?
Anybody?
next prev parent reply other threads:[~2009-10-21 7:17 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <b2cc26e40910100601q7aed04acjcc9973ef06e6458f@mail.gmail.com>
2009-10-11 10:26 ` Enable syn cookies by default Frans Pop
2009-10-15 8:59 ` Olaf van der Spek
2009-10-16 8:55 ` Jarek Poplawski
2009-10-16 19:01 ` Jarek Poplawski
2009-10-16 19:56 ` Florian Westphal
2009-10-16 19:49 ` [PATCH 1/2] syncookies: print synflood warning if syn queue is full Florian Westphal
2009-10-16 19:51 ` [PATCH 2/2] syncookies: enable by default Florian Westphal
2009-12-08 14:47 ` [PATCH 1/2] syncookies: print synflood warning if syn queue is full Olaf van der Spek
2009-12-08 21:09 ` David Miller
2010-01-27 17:01 ` Olaf van der Spek
2009-10-21 7:17 ` Olaf van der Spek [this message]
2009-10-21 7:25 ` Enable syn cookies by default Eric Dumazet
2009-10-21 7:48 ` Olaf van der Spek
2009-10-21 9:16 ` William Allen Simpson
2009-10-21 10:10 ` Olaf van der Spek
2009-10-21 18:36 ` William Allen Simpson
2009-10-21 18:45 ` Olaf van der Spek
2009-10-21 13:04 ` David Miller
2009-10-21 18:04 ` William Allen Simpson
2009-11-13 12:42 ` Olaf van der Spek
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