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

[Brian E Carpenter]

On 31-Jul-23 22:11, Thomas Schäfer wrote:
> Ondřej Caletka
> 
> (https://mastodon.social/@Oskar456/110807321268094472 )
> 
> was so nice to provide a test setup.
> 
> 
> So I've set up some testing DNS records. The results are a bit
> surprising. Try it yourself:
> 
> https://ipv4-mapped.0skar.cz/ (AAAA with IPv4-mapped, should not be
> reachable from anywhere)
> https://ipv4-mapped-pref.0skar.cz/ (dual stack A plus AAAA with IPv4-mapped)

Both OK from my Auckland NZ dual stack, and Firefox/SixOrNot reports an IPv4
connection (as expected).
  
> 
> Despite it works in most dual stack environments and most
> ipv6-mostly/only environments, it breaks when nat64 without clat is used.

This seems normal. I like discovering things that are broken with nat64.

Thanks Thomas and Ondřej,

     Brian