spf ent txt records.

John Wobus jw354 at cornell.edu
Fri Mar 22 17:11:35 UTC 2013


On Mar 18, 2013, at 12:00 AM, Mark Andrews wrote:
> It's not that is is esthetically pleasing to put SPF data into its
> own RR type.  It's that TXT has been hijacked and contining to add
> more uses to TXT does not scale.  TXT is a reasonable record for
> proof of concept.  It isn't and never has been a good long term
> choice.

Absolutely.  What we should be pushing for is a spec such that if
followed, is sufficient to work, for SPF and for other users of TXT.
We should be on that track even if it is necessary to allow a lot
of time to accommodate the effort.  Ways I can see to get
back there:

1) An RFC (or RFCs) that specifies a set of specific TXT record content
formats that are specified to have particular meanings, e.g. 'don't do  
the
following unless it's an SPF record'.

2) Going even further, layer another protocol (and registry) on top
of TXT records specifying the meaning of various prefixes.

3) Transition widely-used systems that are prototyped with TXT
to an RR type specified for the purpose.

The last could even be a new TXT-like RR type invented specifically for
supporting for layering more protocols, along with a registry of  
prefixes.
I'm not enamored of that, but at least it gives the world the means to
avoid tripping over each other's feet.

It's natural that folks whose primary interest is SPF should find
all this to be busy-work of little value to themselves or
their customer base.  The benefit is for future efforts of
the SPF-sort, and it's been fortunate for the
SPF effort that TXT records were available to them without
a lot of earlier-established complicated rules of use, so they
could use TXT records to jump-start their efforts.

John Wobus
Cornell U



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