spf ent txt records.

Vernon Schryver vjs at rhyolite.com
Mon Mar 18 03:29:34 UTC 2013

> From: Mark Andrews <marka at isc.org>

> Yet libspf2 requests SPF records and falls back to TXT on NODATA.
> It does not do a TXT query if it gets a SPF response.

Even if my option of SPF is insane, compare the 2008 dates on
http://www.libspf2.org/ and the 2012 date on the surveys in RFC 6686.
It's clear that for whatever real world reasons, libspf2 was not
dispositive and that draft-ietf-spfbis-4408bis-12 is right to
deprecate the SPF type in section 3.1.

> The rational course would be to set a sunset date on TXT style spf
> records.  April 2016 looks like a good date.  10 years after RFC
> 4408 was published.

The rational course usually starts with accepting reality as it is.

In the real world, flag days are ignored by most people until there
is clear profit in honoring them or loss in ignoring them.  A loss can
be "We've stopped updating the hosts file so if you want your stuff
to work, you better get busy with the DNS."  Wasting a round trip to
get NODATA for the SPF RR for google.com or hotmail.com before requesting
the TXT RR is not a profit.  There is no real world profit in "It is
esthetically pleasing to put SPF data into its own RR type."

Your flag day for turning off IPv4 in the core must be soon, because
IPv6 has already been baking for a lot longer than 10 years.  Besides,
unlike TXT for SPF, IPv4 has real problems in the real world.

Vernon Schryver    vjs at rhyolite.com

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