IPv4-Mapped IPv6 Address used in DNS with AAAA-records

[Nick Hilliard]

Thomas Schäfer wrote on 27/07/2023 10:16:
> Is there a paper, source, a person with high reputation, who can clearly 
> confirm that?

yes and no. In terms of authoritative status of ipv4-mapped ipv6 
addresses, these are not globally reachable addresses, which means that 
if you jam them into a DNS view which is publicly visible, the behaviour 
is at best undefined, and more than likely to cause breakage:

> https://www.iana.org/assignments/iana-ipv6-special-registry

See the "Globally Reachable" field. If you're looking for canon, then 
this is probably what you need.  Note that it doesn't say anything about 
your own internal administrative domain.

There's no document that I'm aware of which says you must not insert 
ipv4-mapped ipv6 addresses into the DNS.  Generally the IETF steers 
clear from issuing documents which advise against doing stupid things 
because, well, they're stupid and if you point a gun at your foot, then 
take off the safety, then pull the trigger, you'll shoot your foot off, 
and you'll quickly learn why doing all these things is considered to be 
a bad idea.

In terms of arguing, sometimes people cannot be argued with.

Nick