DHCPv6 - unicast option does not work

[Mudric, Dusan (Dusan)]

>Hi,
>
>I am using ISC DHCPv6 v4.3.5 server. Cannot make the server to send the Server Unicast option. The server didn't >include this option in ADVERTISE or REPLY.
>
>I used
>"option dhcp6.unicast 2000::101;"
>Based on ISC DHCPV6 options https://urldefense.proofpoint.com/v2/url?u=http->3A__www.ipamworldwide.com_ipam_isc-2Ddhcpv6-2Doptions.html->3A&d=DQICAg&c=BFpWQw8bsuKpl1SgiZH64Q&r=UT3Bk9cbLeaJxhf3iCrhIoUWB8YLZU23029sMQGQ2kY&m=dQdlFygcUOtJ>a4wtjI8yMvbypHekOQGn-eh5mJqw31E&s=79rndb2txaQPcH0_wSKmH7bmH-rSPEggBzfkFmb3eH4&e=  
>
>12	OPTION_UNICAST	dhcp6.unicast	IPv6 address
>
>that should work. 
>
>What do I need to configure on the server, to see the unicast option in ADVERTISE?
>
>Regards,
>Dusan Mudric.

There was no reply for this post. ISC server experts, please help.

Thanks,
Dusan.