[DNSOP] Re: [happy] Indicating ipv6only and deprecation via SVCB: draft-nygren-dnsop-ipv6only-indicator-00.txt

If I understand correctly, the benefit of the "ipv6only" flag is:

1. Dual-stack clients can skip the "A" query, for efficiency.
2. IPv4-only clients can avoid waiting for the NODATA response to the
A query before trying the next SVCB record.

DNS queries are cheap enough that #1 doesn't seem very compelling.
(SVCB wastes a _lot_ of queries already.)  #2 seems like it could be
valuable in some situation, but the benefit is only to v4-only
clients.  I imagine that in this deployment scenario, those clients
are not highly performance-sensitive.

I do think the "deprecated" flag is interesting.  However, I wonder if
it would be better as a collection of logging flags like "warning=",
"info=", etc.  "Deprecated" seems like too narrow a meaning here.

--Ben

On Mon, Jul 6, 2026 at 6:35 PM Erik Nygren <[email protected]> wrote:
>
> I've published a -00 draft proposing two new SvcParams for "ipv6only" and for "deprecated", along with some operational examples for how they might be used together. Abstract: As the DNS is the primary mechanism for translating
> 
> I've published a -00 draft proposing two new SvcParams for "ipv6only" and for "deprecated", along with some operational examples for how they might be used together.
>
> Abstract:
>
>    As the DNS is the primary mechanism for translating from hostnames to
>    IP addresses, it is a logical place to signal that endpoints are
>    IPv6-only.  It is thus also a logical place to signal that legacy
>    endpoints supporting IPv4 are being deprecated.  This specification
>    introduces two SvcParams for SVCB-compatible RR types that signal
>    IPv6-only endpoints (ipv6only) as well as deprecated endpoints
>    (deprecated).
>
> The "ipv6only" SvcParam touches on V6OPS and HAPPY.  I see this not as something we desperately need now/yet but as something we will want in a few years and thus should standardize sooner so that the implementations are there for when we need it.
>
> The "deprecated" SvcParam is more generally useful. I give some other examples of how it might be used for other purposes as well (eg, for deprecating an http/1.1-only Service Endpoint).
>
> I'm still the only author on this, and am happy to talk to people in Vienna if there others interested in joining as co-authors.  This idea has been tossed around a number of times while we were authoring RFC 9460 / SVCB (and might have been in some early drafts and I even vaguely recall talking about some precursors to this in sunset4 and in happy).
>
> Best, Erik
>
>
> ---------- Forwarded message ---------
> From: <[email protected]>
> Date: Mon, Jul 6, 2026 at 5:54 PM
> Subject: New Version Notification for draft-nygren-dnsop-ipv6only-indicator-00.txt
> To: Erik Nygren <[email protected]>
>
>
> A new version of Internet-Draft draft-nygren-dnsop-ipv6only-indicator-00.txt
> has been successfully submitted by Erik Nygren and posted to the
> IETF repository.
>
> Name:     draft-nygren-dnsop-ipv6only-indicator
> Revision: 00
> Title:    Indicating IPv6-only SVCB Endpoints and IPv4 Deprecation in the DNS
> Date:     2026-07-06
> Group:    Individual Submission
> Pages:    11
> URL:      https://www.ietf.org/archive/id/draft-nygren-dnsop-ipv6only-indicator-00.txt
> Status:   https://datatracker.ietf.org/doc/draft-nygren-dnsop-ipv6only-indicator/
> HTML:     https://www.ietf.org/archive/id/draft-nygren-dnsop-ipv6only-indicator-00.html
> HTMLized: https://datatracker.ietf.org/doc/html/draft-nygren-dnsop-ipv6only-indicator
>
>
> Abstract:
>
>    As the DNS is the primary mechanism for translating from hostnames to
>    IP addresses, it is a logical place to signal that endpoints are
>    IPv6-only.  It is thus also a logical place to signal that legacy
>    endpoints supporting IPv4 are being deprecated.  This specification
>    introduces two SvcParams for SVCB-compatible RR types that signal
>    IPv6-only endpoints (ipv6only) as well as deprecated endpoints
>    (deprecated).
>
>    TO BE REMOVED: This document is being collaborated on in Github at:
>    https://github.com/enygren/draft-nygren-dnsop-ipv6only-indicator
>    (https://github.com/enygren/draft-nygren-dnsop-ipv6only-indicator).
>    The most recent working version of the document, open issues, etc.
>    should all be available there.  The authors (gratefully) accept pull
>    requests.
>
>
>
> The IETF Secretariat
>
>
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