domain-name-server in IPv6 mode

[Vladimir-M. Obelic]

What is the current status of this option?
When I try to configure the option domain-name-server
2000:dead:beef::1 I can't even start the server as config file can't
be parsed (IP address or hostname expected).
The server is running always in v6 mode.
When I try to configure a v4 DNS server in v6 mode, I am not getting
any DNS option in advertise/reply messages, even when a dhcpv6 client
requests RDNS.

Regards,
Vladimir