Re: [dnsext] SPF, a cautionary tale

[Mark Andrews <[e-mail]>]

In message <[e-mail]>
, Phillip Hallam-Baker writes:
> 
> On Mon, May 6, 2013 at 2:58 PM, <[e-mail]> wrote:
> 
> >
> > > I'm an existence proof that your claim is false.  I've read RFC5507 and
> > I'm
> > > familiar with its contents.  I've already said that, were we writing this
> > > anew, I think we'd likely be taking a different path here, one that would
> > > make the members of dnsext much happier.  But since the former is false,
> > > and there's a substantial deployed base much of which is unlikely to
> > change
> > > its behaviour for various reasons, we have to look at this a different
> > way.
> >
> >
> >         there is this wonderful thing called "O'Dells Law" which,
> > paraphrased
> >         is:  "The installed based doesn't matter".   However, there is
> > nothing
> >         preventing the SPF community from using TXT to store thier
> > particularly
> >         unique stuff.  But there can be zero whining when other folks use
> > TXT for
> >         their own purposes and confuse the heck out of SPF processors
> > which get
> >         (for thier purposes) malformed SPF data...
> >
> >
> O'Dells Law only applies AFTER you have reached critical mass and growth is
> automatic.
> 
> If you are in a situation where the installed base meets the requirements
> just fine then the new proposal doesn't matter and will actually shrink
> over time as a percentage of the installed base as people continue to use
> the legacy system.
> 
> If the numer of domains with feature X is growing at a significantly faster
> rate than the Internet then it will become ~100% in due course.
> 
> If the numer of domains with feature X is growing at a significantly slower
> rate than the Internet then it will become ~0% in due course.
> 
> 
> About one year after an RFC has been published there is sometimes a sudden
> shock of realization that maybe deployment did matter after all. Catching
> an existing system is very hard. Apart from POP vs IMAP and WWW vs Gopher,
> I can't remember any examples offhand.
> 
> -- 
> Website: http://hallambaker.com/

Both SPF queries and SPF records are growing w.r.t. TXT records
and queries so the arguement is moot.

Mark

-- 
Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
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