No hat
On Wed, Aug 21, 2013 at 12:26:51PM +0200, Eliot Lear wrote:
However, in this case, it is not in dispute that queries are happening.
Actually, that _was_ in question. Remember, part of the justification
for ditching TYPE99 is not only that publishers don't use it, but also
that if they did there'd be no benefit.
The evidence the WG produced was that there were hardly any validators
querying for SPF. The WG originally had somewhat stronger claims in
the draft, and I objected because I felt our sample wasn't good
enough. The data that Patrik and David have presented suggest that
there might indeed be more to the story, but again there are some
issues with the samples.
There are two additional things that would help make sense of these
numbers. First, the raw number of queries isn't very interesting, if
mail transactions all turn out to be with the same parties. We can't
count the same party asking for TYPE99 twice as two validators.
Second, how many of these TYPE99 queries arrive within the same time
frame (yes, I'm waving my hands)? If the TYPE99 queries are being
issued at the same time as the TXT record, that's an indication that
the query source actually has no preference, and just wants the answer
that comes fastest.
The evidence that the WG looked at suggested that really only Yahoo
preferred TYPE99, and that they stopped preferring it. There was one
large mail system (I can't recall who) that sent TYPE99 queries, but
actually sent both SPF and TXT at the same time in an effort to get
the quickest response possible. As Scott has noted elsewhere in this
thread, the SPF processing is often a blocking operation for mail
systems, so latency added by two lookups in that processing is a big
deal (particularly for very large systems).
* To what extent has that happened?
I'm not the shepherd, but it is undeniable that most current-era
shipping DNS servers support RRTYPE 99.
Best regards,
A
--
Andrew Sullivan
ajs(_at_)anvilwalrusden(_dot_)com