Skip site navigation (1)Skip section navigation (2)
Date:      Tue, 14 Sep 2010 04:30:53 -0700
From:      Jeremy Chadwick <freebsd@jdc.parodius.com>
To:        Gareth de Vaux <bsd@lordcow.org>
Cc:        stable@freebsd.org, luigi@freebsd.org
Subject:   Re: ipfw: Too many dynamic rules
Message-ID:  <20100914113053.GA19053@icarus.home.lan>
In-Reply-To: <20100914111200.GA59889@lordcow.org>
References:  <20100909153902.GA28341@lordcow.org> <20100909162009.GA80375@icarus.home.lan> <20100910114908.GA55978@lordcow.org> <20100914103657.GA57521@lordcow.org> <20100914110302.GA84971@icarus.home.lan> <20100914111200.GA59889@lordcow.org>

next in thread | previous in thread | raw e-mail | index | archive | help
On Tue, Sep 14, 2010 at 01:12:00PM +0200, Gareth de Vaux wrote:
> On Tue 2010-09-14 (04:03), Jeremy Chadwick wrote:
> > You're absolutely certain these are all in FIN_WAIT_2 state and not
> > TIME_WAIT?
> 
> Yup,
> 
> $ netstat -an | grep FIN_WAIT_1 | wc -l
>       57
> $ netstat -an | grep FIN_WAIT_2 | wc -l
>      431
> $ netstat -an | grep TIME_WAIT | wc -l
>       17

Regarding net.inet.tcp.finwait2_timeout=15000 -- you don't see any
improvement at all?  That's a bit strange.  There's probably something
about ipfw I'm not getting.  Adding luigi@ to the CC list, since I think
he's familiar with ipfw internals.

FWIW, I'd recommend keeping an appended log of output from something
like this script:

while true
do
  echo "`date` -- `netstat -n | grep -c FIN_WAIT_2`" >> /some/log
  sleep 5
done

Just make sure the sleep interval is lower than the FIN timeout.

Another thing to try: setting net.inet.tcp.fast_finwait2_recycle=1 and
see if this makes a difference.  I'm not familiar with this setting
myself, but some Google results indicate some people do use it.  The
sysctl description is a bit vague too.

-- 
| Jeremy Chadwick                                   jdc@parodius.com |
| Parodius Networking                       http://www.parodius.com/ |
| UNIX Systems Administrator                  Mountain View, CA, USA |
| Making life hard for others since 1977.              PGP: 4BD6C0CB |




Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20100914113053.GA19053>