[dns-operations] resolv.conf and resolving IPv6-only domains/NSes

[Zuleger, Holger, VF-DE]

> Stephane:
> 
> You are correct, whether my tool requests resolution via IPv4 
> or IPv6 for
> onlyv6.com shouldn't matter as long as the queried resolver has IPv6
> connectivity.
> 
> So what I've learned is that if I want to resolve query 
> v6-only domains,
> such as onlyv6.com, I had better make sure that the first DNS 
> server in my
> resolv.conf has IPv6 connectivity.  Even better, make sure 
> all of them do.
No.
If your client is ipv6-only then it doesn't make sense to
use an IPv4 resolver.
Additionally each of the ipv6 resolvers in your list *must* be
dual-stack, or need the help of an dual stack resolver (e.g. via
BINDs dual-stack-server command).

If the domain is a v6-only domain, at least the authoritative name
servers of
the domain have to be dual stack.

Regards
 Holger