[atlas] beta status page vs. ipv6 only network

On Fri, Jan 12, 2018 at 11:02:02AM +0100,
 Robert Kisteleki <robert at ripe.net> wrote 
 a message of 31 lines which said:

> I'd think it's relatively difficult to automatically (i.e. system)
> tag probes as "intentionally single stack", as we don't really know
> if that's a misconfiguration (e.g. DHCP server is down) or
> intentional.

Note there is some work at the IETF, in the sunset4 working group, to
address this very problem. Document draft-ietf-sunset4-gapanalysis
(the gap analysis) describe it as "3.1.  Indicating that IPv4
connectivity is unavailable PROBLEM 1: When an IPv4 node boots and
requests an IPv4 address (e.g., using DHCP), it typically interprets
the absence of a response as a failure condition even when it is not."

There is no standard solution today. Document
draft-ietf-sunset4-noipv4 proposed "a new DHCPv6 option and a new
Router Advertisement option to inform a dual-stack host or router that
IPv4 can be turned off" but this document died, I don't know why.