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Date: Thu, 30 Oct 2003 13:01:37 +1000 (EST)
From: Andy Farkas <andyf@speednet.com.au>
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To: Jarkko Santala <jake@iki.fi>
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cc: security@freebsd.org
cc: Kris Kennaway <kris@obsecurity.org>
Subject: Re: Best way to filter "Nachi pings"?
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On Mon, 27 Oct 2003, Jarkko Santala wrote:
> On Mon, 27 Oct 2003, Kris Kennaway wrote:
> > On Mon, Oct 27, 2003 at 11:06:52AM +0200, Jarkko Santala wrote:
> > >
> > > Definitely this block-all approach is not sane, its like if someone
> > > complains about NFS being broken you'd say disable it. Filtering packets
> > > by length on the other hand is a very nice feature to have.
> >
> > As it happens, ipfw[2] does this anyway.
>
> IMHO this is the correct answer that might have been given right away.

So, using IPFW2, a rule to block the nachi ping would look like:

  add deny icmp from any to any in icmptypes 8 iplen 92

correct?

--

 :{ andyf@speednet.com.au

        Andy Farkas
    System Administrator
   Speednet Communications
 http://www.speednet.com.au/