[v6ops] Re: ICANN asking for input: Proposal to use ::ffff:7f00:3535 for a special use / meaning…

[Mark Smith <[e-mail]>]

I'll submit this to ICANN, however the first thing I'd point out is that
the way to request input from the IETF is to submit an Internet Draft.

They claim 127.0.53.53 has already been allocated for a similar purpose. No
it hasn't, it's not in IANA's reserved IPv4 address registry, because the
IETF and IANA haven't designated it with any special meaning.

On Wed, 29 Oct 2025, 22:34 Warren Kumari, <[e-mail]> wrote:

> [ Note: Sent to both V6OPS and 6MAN (as separate messages) as it applies
> to both ]
>
> The 50'000ft overview is that, before a string (like .example) becomes a
> TLD, a test delegation is created which will return 127.0.53.53
> and ::ffff:7f00:3535. Users / admins of networks that might be using the
> string internally are expected to see these addresses in e.g logs and know
> that this means that the string will become a TLD soon, and they should
> stop using it…
>
> The ICANN public comment is asking for feedback on if this is an
> acceptable address to use.
> The Public Comment is here:
> https://www.icann.org/en/public-comment/proceeding/name-collision-ipv6-research-study-20-10-2025
>
> Seeing as this proposes using an RFC4038 - "Application Aspects of IPv6
> Transition" <https://datatracker.ietf.org/doc/rfc4038/> address in a
> non-standard way, I figured it would be useful for V6OPS / 6MAN people to
> review and provide input.
>
> W
>
> P.S: V6OPS is mentioned in the study:
> "ICANNs preferred approach would be to use an IPv6 loopback address
> analogous to the
> existing IPv4 127.0.53.53 address, however, IPv6 has only a single
> loopback address
> allocated (::1 [RFC 4291]). Two proposals within the IPv6 Operations
> working group at the IETF
> to assign a larger loopback prefix have not gained consensus and as a
> result there is still no
> direct equivalent IPv6 address available today. Should such an address
> become available in the
> future ICANN would intend to utilize it for Controlled Interruption. In
> lieu of that, and with a
> recognition of the current impact of not publishing a AAAA record for
> Controlled Interruption, an
> alternative option that can be deployed as an interim solution is highly
> desirable.
> A new research study has been performed to identify one or more IPv6
> addresses that may be
> suitable for use during Controlled Interruption. This study involved a
> review of the IANA
> registries for IPv6 to produce a list of candidate addresses, followed by
> technical tests of
> popular end-user operating systems to determine whether or not DNS lookups
> that produce
> responses containing these addresses result in external network traffic."
>
>
> _______________________________________________
> v6ops mailing list -- [e-mail]
> To unsubscribe send an email to [e-mail]
>