Dave Crocker <dhc(_at_)dcrocker(_dot_)net> writes:
My concern is not about efficiency. It is about the fundamental
ability to get any successful interoperability.
I'm concerned about that as well, but efficiency is a concern if you're
trying to process mail as quickly as possible. The limit of 10
redirects/includes is a bit worrisome too.
If there is no core requirement for support of a particular record
type, then there will be clients that support only one record type and
servers that support only another. This means that the clients will
not be able to access the information.
The instant you talk about "duplicate queries" you are assuming that
the client supports more than one type. The question is whether they
are required to. That is, do they have a MUST for each type?
There definitely needs to be a shared MUST for one type. At that point,
though, how much point is there in even mentioning the other?
I absolutely don't want to see a MUST for two types for the receiver if
there's no schedule for phasing TXT out.
For Internet-scale services there can be no such thing as a flag day.
There is not central authority to assert it. Even if there were,
there is no way to coordinate that scale of operation. Even centrally
controlled companies cannot do flag-days for large-scale deployment
changes.
I agree it's not entirely practical, but as there is no easy or fast way
to deploy new RR types, we're limited to the non-practical. Your point
is well made. Maybe "flag day" is overstated, but a predefined
recommended phase-out schedule would be a good idea if the TXT record is
optional.
Daniel
--
Daniel Quinlan
http://www.pathname.com/~quinlan/