SLAAC and DNS, no really - what's the deal?

The original (and still valid) idea is to combine IPv6 addresses with SLAAC/autoconf with Router Advertisements (RA's), combined with Stateless DHCPv6 for all other options like DNS. This makes the DHCPv6 server very simple because it doesn't have to maintain a leases database and things like that. It only needs to tell the client all the extra options like DNS domain and resolver.

The IPv6 design was pretty academic at its inception, I would look at the IETF IPng working group mailing list and doucment archives if you want the whole story. But the charter was to replace just the IP layer, leaving all of the higher-layer protocols to others. Remember that IPv4 didn't have DHCP, BOOTP, or even DNS until many years after deployment. Getting those things to work on IPv6 was left to other IETF groups.

The other IETF groups didn't exactly jump on the IPv6 bandwagon right away, nor did vendors, implementers, ISPs, network admins, or anyone else. So now we have a right mess on our hands.