IPv6: Non-SLAAC Addressing of Local Interfaces with Prefix Delegation?

Hi there

My ISP is using prefix delegation to assign an IPv6 range to my router (running FreeBSD 10). I have managed to set up dhcp6c (I think this is KAME's wide-dhcpv6?) to receive the prefix as well as configure the "outside" interface (receive RA and default gateway). That is about what [1] also explains.

Now, dhcp6c is assigning SLAAC addresses to my "internal" interfaces and rtadvd is sending out advertisments.

But I would like to "manually" assign addresses to these interfaces (e.g. <whatever prefix>:<I chose using sla-id>::1).

There are posts/blogs out there (e.g. [2]) that seem to be using "ifid" in dhcp6c.conf, but I think that is not possible on FreeBSD/with my version of wide-dhcpv6.

Is there a way to achieve this? Is rtsol involved/does it need to be involved?

Best regards

[1] https://forums.freebsd.org/threads/ipv6-gateway.53522/page-2#post-301886
[2] http://www.ipcalypse.ca/?p=204