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Re: [nsp] known networks for broadcast ping attacks
From: "Jay R. Ashworth" <jra () scfn thpl lib fl us>
Date: Thu, 31 Jul 1997 01:19:24 -0400

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.

-- jra
Jay R. Ashworth                                                jra () baylink com
Member of the Technical Staff             Unsolicited Commercial Emailers Sued
The Suncoast Freenet      "People propose, science studies, technology
Tampa Bay, Florida          conforms."  -- Dr. Don Norman      +1 813 790 7592

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