DHCPv6 deleting "A" record?

[Nicolas C.]

Hello,

A few months ago I was experimenting DHCPv6 + DDNS and I recall that the 
DHCPv6 server was deleting the "AAAA" record but also the "A".

The setup : one DHCPv4, one DHCPv6, the option 
"update-conflict-detection" is set to "false" on the DHCPv6.

With "nsupdate", two test records (A and AAAA) are manually recorded in 
the dynamic zone.

This is what I remembered when a client was booting with the same name 
as the test records :

  - The conflict detection is working for IPv4
  - When the DHCPv6 clients starts, a new AAAA records (provided by the 
DHCP) is added in addition of the one already present and a TXT record 
is also added
  - When the DHCPv6 client release its address, all records (A, 2xAAAA 
and TXT) are deleted.

This is what happens today with my tests :

  - The conflict detection is working for IPv4
  - When the DHCPv6 clients starts, the static AAAA record is _replaced_ 
by the one provided by the DHCPv6 server, a TXT record is added
  - When the DHCPv6 client release its address, the AAAA record is 
deleted but the TXT (and the "A") record remains.

Is it possible (under specific conditions) to obtain the first case 
where all records are deleted? I'm currently writing a small article on 
DHCPv4 + DHCPv6 + DDNS and I thought there was a "domino" effect where a 
DHCPv6 server with "update-conflict-detection" disabled could compromise 
IPv4 records.

Thanks,

Nicolas