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RE: is it possible to block ip packets that contains experimentaltcp opt

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Subject: RE: is it possible to block ip packets that contains experimentaltcp options ?
From: Paul Blondé <jpb@entel.ca>
Date: Thu, 17 May 2007 10:25:06 -0700
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I would guess this refers to the following:

http://www.psc.edu/networking/projects/sack/

or, more generally, the options discussed here:

http://www.snort.org/archive-3-186.html



~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Paul Blondé
Web Programmer
enTel Communications Inc
jpb@entel.ca
250.633.5151
866.633.2644
 


> -----Original Message-----
> From: netfilter-bounces@lists.netfilter.org 
> [mailto:netfilter-bounces@lists.netfilter.org] On Behalf Of Marc Cozzi
> Sent: Thursday, May 17, 2007 10:18 AM
> To: netfilter@lists.netfilter.org
> Subject: RE: is it possible to block ip packets that contains 
> experimentaltcp options ?
> 
> 
>  Paul,
> 
> I believe that's correct. Although I'm still not
> Sure what was originally meant by "experimental tcp options".
> 
>   -marc
> 
> > -----Original Message-----
> > From: Paul Blondé [mailto:jpb@entel.ca] 
> > Sent: Thursday, May 17, 2007 11:09 AM
> > To: netfilter@lists.netfilter.org
> > Subject: RE: is it possible to block ip packets that contains 
> > experimentaltcp options ?
> > 
> > I assume that LOG-AND-DROP is your own chain, crafted so that 
> > you can perform both functions with a single entry?
> > 
> > 
> > 
> > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> > Paul Blondé
> >  
> > 
> > 
> > > -----Original Message-----
> > > From: netfilter-bounces@lists.netfilter.org
> > > [mailto:netfilter-bounces@lists.netfilter.org] On Behalf Of 
> > Marc Cozzi
> > > Sent: Wednesday, May 16, 2007 5:19 AM
> > > To: netfilter@lists.netfilter.org
> > > Subject: RE: is it possible to block ip packets that contains 
> > > experimentaltcp options ?
> > > 
> > > 
> > > 
> > > Glenn,
> > > 
> > > Not sure what you mean by "experimental" however, there are some 
> > > conditions of flags that should never occur on the network. 
> > These can 
> > > be trapped with rules similar to the following.
> > > 
> > > iptables -A BLOCKED -m state --state INVALID -j 
> > LOG-AND-DROP iptables 
> > > -A BLOCKED -p tcp --tcp-flags ALL ALL -j LOG-AND-DROP iptables -A 
> > > BLOCKED -p tcp --tcp-flags ALL NONE -j LOG-AND-DROP
> > > 
> > >   --marc
> > > 
> > > 
> > > > -----Original Message-----
> > > > From: Glenn Terjesen [mailto:glenn@webcat.no]
> > > > Sent: Wednesday, May 16, 2007 5:24 AM
> > > > To: netfilter@lists.netfilter.org
> > > > Subject: is it possible to block ip packets that contains 
> > > > experimental tcp options ?
> > > > 
> > > > Hello,
> > > > got a iptables firewall filtering our servers.
> > > > 
> > > > Is it possible to block tcp packets that contains 
> > experimental tcp 
> > > > options ?
> > > > 
> > > > AND is it smart to do so ?
> > > > 
> > > > 
> > > > --
> > > > Mvh Glenn Terjesen @ Webcat AS
> > > > Tlf: +47 37 02 20 20
> > > > E-post: support@webcat.no
> > > > 
> > > 
> > 
> > 
> 
> 



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