User authentication with IPv6 on linux

Hi.
I am currently trying to do an IPv6 network with Netware, Debian 3.1
(2.6.14 kernel) and Windows 2003 Server.
I am having problems installing Netware 6.5 that I needed for user
authentication and DNS/DHCP services. But I would like not to use
Netware 6.5 because there is no real good support.

So I am wondering what I should use to make my server work with IPv6
and authenticate users without using IPv4 and using only Linux and
Windows clients (using Debian for DNS/DHCP services). Is there a way?

I would like to have an answer even if it is "No".

Thanks a lot.