Re: [DNSOP] [Ext] Reserved field in draft-wessels-dns-zone-digest-04.txt

Paul Hoffman <> Wed, 24 October 2018 17:32 UTC

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From: Paul Hoffman <>
To: "Wessels, Duane" <>
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Thread-Topic: [Ext] [DNSOP] Reserved field in draft-wessels-dns-zone-digest-04.txt
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Date: Wed, 24 Oct 2018 17:32:14 +0000
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Subject: Re: [DNSOP] [Ext] Reserved field in draft-wessels-dns-zone-digest-04.txt
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On Oct 24, 2018, at 2:57 AM, Wessels, Duane <> wrote:
>> On Oct 24, 2018, at 12:16 AM, Paul Hoffman <> wrote:
>> Section 5 says:
>>  FOR DISCUSSION: The authors are willing to remove the Reserved field
>>  from this specification if the working group would prefer it.  It
>>  would mean, however, that a future version of this protocol designed
>>  to efficiently support large, dynamic zones would most likely require
>>  a new RR type.
>> Please strongly consider removing the Reserved field so that designing an way to do a message digest over a dynamic zone can be done independently.
>> Quite frankly, if the Reserved field isn't there and it's clear that this is for complete zones, I see no reason why this should even be considered experimental. The mic line at the presentation at the recent DNS-OARC seems to agree with wanting this for real, as soon as possible.
> Thanks for the feedback, Paul.
> Personally I feel like keeping the Reserved field is potentially useful in the future, but harmless if it never gets used. Can you say more about why keeping it prevents independent work?

From the earlier list discussion and your presentation at DNS-OARC, processing dynamic zones is hard, and you might make different choices based on different amounts of dynamicness (dynamicity?). This should cause developers concern about implementing ZONEMD now because there will be an expectation that they will have to implement the changes in the future.

On the other hand, if you indicate "ZONEMD is for the static zones, and there will be a different RRtype for dynamic zones", vendors can choose later whether to implement the new RRtype. As others have said, new RRtypes are cheap.

> I would be very happy with standards track, but to the extent the WG is skeptical I would settle for experimental at this time.

I am not skeptical of the current protocol: I am skeptical of unknown changes to it in the future.

--Paul Hoffman