IPv6 and commit d882add695bbd5ea03961c08ac2c0380fbf2947b

[Jeremy Allison]

On Fri, Sep 16, 2022 at 01:33:26PM -0700, Jeremy Allison via samba-technical wrote:
>On Fri, Sep 16, 2022 at 04:17:46PM -0400, Nathaniel W. Turner via samba-technical wrote:
>>Hi folks,
>>
>>I'm investigating an apparent regression in IPv6 support in the "net"
>>command, and I have some questions about commit
>>d882add695bbd5ea03961c08ac2c0380fbf2947b.
>>
>>It looks like it was intended to improve and simplify DNS lookups, but
>>unless I'm reading it wrong, it seems to have introduced the assumption
>>that if a DC has IPv4 addresses, all clients will too.
>>
>>If a DC is configured to support both IPv4 and IPv6, and a client in that
>>environment is configured IPv6-only (e.g. as part of a transition to
>>all-IPv6), it looks like the logic will pick one of the DC's IPv4 addresses
>>and ignore it's IPv6 addresses.
>>
>>Am I missing something?
>
>No that's probably correct. I didn't think I'd
>changed the logic here, but it seems I did.
>
>If you'd like to log a bug and send a fix for this
>to gitlab, I'm happy to review and get it into
>the supported trees.

This is internal to discover_dc_dns(), so you
could probably add an extra flag here to tell
discover_dc_dns() to return IPv6-only, and
have it skip that DC if it doesn't have an
IPv6 address returned.