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From: Lawrence MacIntyre <macintyrelp@ornl.gov>
To: Jan Engelhardt <jengelh@linux01.gwdg.de>
Cc: linux-kernel@vger.kernel.org
Subject: Re: Hung Port
Date: Wed, 17 Jan 2007 12:39:10 -0500	[thread overview]
Message-ID: <45AE5F3E.4020500@ornl.gov> (raw)
In-Reply-To: <Pine.LNX.4.61.0701171756050.18562@yvahk01.tjqt.qr>

If that was the case, would the port not show up in TIME_WAIT state?
Also, the kernel should only hold a closed socket in TIME_WAIT state for
2 minutes or so.  These hung ports stay around until the machine is
rebooted.

This one time, at band camp, Jan Engelhardt wrote:
>> Last week I had a port (TCP:52557) that was mysteriously unavailable on
>> my ubuntu machine (running kernel 2.6.15-27-k7 #1 SMP PREEMPT).  If you
>> tried to bind to it, it was unavailable.  However, nmap (both to
>> localhost and from an external host) reported the port closed.  fuser,
>> lsof, and netstat had no record of the port being used.
> 
> Did your application forgot to set SO_REUSEADDR?
> 
>>  Our firewall
>> logs didn't show any unusual traffic to the machine.  Nor did they show
>> any traffic at all to/from that port on the machine.  After checking
>> everything I could think of, I rebooted it, and there were no ports that
>> were unavailable in this way when it came back up.  This morning another
>> hung port has appeared (TCP:43355).  My best guess is that this is an
>> ephemeral port that has somehow gotten hung in the kernel somewhere.
>> Has anyone seen anything like this and/or is there anything else I could
>> look at to figure it out?
> 
> 	-`J'

-- 
  Lawrence MacIntyre   865.574.8696   macintyrelp@ornl.gov
                Oak Ridge National Laboratory
Cyber Security and Information Infrastructure Research Group

Protect your digital freedom and privacy, eliminate DRM.
Learn more at http://www.defectivebydesign.org/what_is_drm

      reply	other threads:[~2007-01-17 17:39 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-01-17 15:54 Lawrence MacIntyre
2007-01-17 16:56 ` Jan Engelhardt
2007-01-17 17:39   ` Lawrence MacIntyre [this message]

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