I was running assisted mode when it self-assigned the MAC based address with the LAN prefix. So the prefix info must have been available.

Router Advertisement "Assisted" mode will also support autoconfiguration. Sort of a DHCPv6 and SLACC mix.

Did notice though that with autoconfiguration it didn't seem to get the local dns server. Maybe there is some additional config needed for that. I force all dns to use local resolver. All other ...

DHCPv6 server is configured to handout addresses for the LAN and works with other DHCPv6 clients for reserved and non-reserved addresses.

LAN Prefix: xxxx:xxxx:xxxx:xxx1
Reserved Host: HDHR4-2US ::200

HDHR4-2US should get xxxx:xxxx:xxxx:xxx1::200
Instead is has xxxx:xxxx:xxxx:xxx1: + IPv6 ...

Been running IPv4 only with reserved DHCP provided address.
Recently have enabled IPv6 on the WAN & LAN.
Noticed today that the HDHR4-2US has assigned itself an IPv6 address based on the LAN prefix (not link-local) and it's MAC address.

How can I make it obtain it's IPv6 address from the DHCPv6 ...