[11509] in North American Network Operators' Group
Re: [nsp] known networks for broadcast ping attacks
daemon@ATHENA.MIT.EDU (Jay R. Ashworth)
Thu Jul 31 01:51:31 1997
Date: Thu, 31 Jul 1997 01:19:24 -0400
From: "Jay R. Ashworth" <jra@scfn.thpl.lib.fl.us>
To: Joe Rhett <jrhett@ISite.Net>
Cc: nanog@merit.edu
In-Reply-To: <199707310515.WAA03848@narc.noc.isite.net>; from Joe Rhett <jrhett@ISite.Net> on Wed, Jul 30, 1997 at 10:15:24PM -0700
On Wed, Jul 30, 1997 at 10:15:24PM -0700, Joe Rhett wrote:
> > .255 is _always_ a broadcast address, no?
>
> Uh, no. If the bit mask is smaller than /24, any given .255 address could
> be legitimate.
RFC 917 and RFC 922 (admittedly old) suggest strongly that this isn't a
good idea; I'm still searching to find the reference I remember that
specifically deprecates it.
I guess it matters, since I'm not aware of routers that allow the
specification of filter rule addresses with /netsizes.
Cheers,
-- jra
--
Jay R. Ashworth jra@baylink.com
Member of the Technical Staff Unsolicited Commercial Emailers Sued
The Suncoast Freenet "People propose, science studies, technology
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