Re: [Uta] draft-ietf-uta-mta-sts-07 STS policy removal.

Viktor Dukhovni <ietf-dane@dukhovni.org> Thu, 10 August 2017 17:47 UTC

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Subject: Re: [Uta] draft-ietf-uta-mta-sts-07 STS policy removal.
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On Thu, Aug 10, 2017 at 10:02:41AM -0700, Daniel Margolis wrote:

> Also, note that this slightly oddifies the _DNS_ caching story; the
> NXDOMAIN TTL is derived from the SOA record, so unlike a "real" TXT record,
> the TTL on the "null" record comes (obviously) from a different place,
> which is a little bit (but only a little bit) weird in terms of usability
> of the configuration parameters, so to speak.

Yes, the negative TTL is from the SOA, but the TXT record TTL is
not something the sending MTA has to concern itself with, the TTLs
are handled transparently by the resolver.  The difference might
plausibly matter to the administrator of the receiving domain, who
might want to adjust the negative TTL, but he might do that regardless
of whether we refresh cached (!= "none") policies even when the
TXT is not present.  That is, if you want a shorter or longer
negative TTL, you would do tune it regardless of how we decide this
question.

> If anyone else has read this far on the thread, I'm happy to get feedback
> on this proposal from others on the list.

Yes, please!

-- 
	Viktor.