Re: [dnsext] SPF, a cautionary tale

[Phillip Hallam-Baker <[e-mail]>]

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/