We have a Server 2008 DHCP server that has an existing ipv4 scope, but no ipv6 scope. I do not recall whether the DHCP server was set to stateless or stateful mode. So i have several questions. How do you check the mode of the ipv6 portion of the DHCP server? Can you toggle the mode after the fact? After you have the server in stateful mode, what do you need to set up a scope for ipv6? Are there any guideline/best practices that tell you how to configure the prefix and scope ranges? I have the Microsoft press book Understanding IPv6, but it is very technical and i am not sure that the answers that i am looking for are in it. Any help would be appreciated. Thanks.

In very simple terms,+ Stateful configuration - you will keep track of IPassociated to client machines+ Stateless Configuration - You will not keep track of IP associated with individual client machinesSpecific to IPv6,We can allocate IP to client machines in 2 way, first through DHCP and second through Router Advertisement, where will only tell what prefix to use and client machine will generate its own host part of IP. Even in stateless configuration we need to use DHCP server for assigning DNS address to client machines. With router advertisement we can only tell IP and default gateway addressclient can use.Few URL which will help you with your design and deployment,http://support.microsoft.com/kb/961344/EN-US- How to configure a Windows Server 2008 DHCP server using an IPv6 scope to register clients in DNS when requestedhttp://blogs.technet.com/teamdhcp/archive/2007/01/27/dhcpv6-stateless-and-stateful-server-in-windows-server-longhorn.aspx- Some insights about modeshttp://technet.microsoft.com/en-us/network/bb643151.aspx- each and everything about DHCPhope this helps.

Sorry forgot to mentioned,+ You cannot change mode post installation of DHCP service.+ By default DHCP will be installed with stateless configuration.+ But we can configure scope level settings as those are used in stateful configuration as well.

Thanks for the info. In the interim, I started setup of a new DHCP server on new hardware that i am planning on transitioning to. This time i made sure that i chose 'Disable Stateless mode' when i set up DHCP. My critical questions are: Are there any guidelines/best practices for picking/generating a prefix (similar to internal LAN being 10.10.10.x)? I assume that the server NIC has to have a static IPv6 address the same as with IPv4? Are the transitioning technologies (6to4, teredo, etc) set up automatically or separately?For the 'do it all' admin on a small network, it would be nice to have a how to forDHCPv6 setup that included these answers. I intend todeploy DirectAccess when Server 2008 R2 comes out and i know it relies on IPv6. So i reallyneed toget this set up correctly. In a followup, after some additional reading, i used the SixXS site to generate a unique prefix for our local lan that is registered there. However, the prefix that i have is /48 bit prefix and Server 2008 DHCP asks for a /64 bit prefix. So do i just choose a random 16 bit number to fill in the fourth portion of the prefix? Am i making this too difficult? should i just revert to stateless mode?

Answering last question first - If you would like to reduce administrative task, it will be good to move to stateless configuration.+ Are there any guidelines/best practices for picking/generating a prefix (similar to internal LAN being 10.10.10.x)? - By default all machines will have 64 bit host ID and 64 bit Network ID (needs more understanding of IPv6 protocol). If you got 48 bit network ID, which mean you have 16 bits for subnetting or play with it.+ I assume that the server NIC has to have a static IPv6 address the same as with IPv4? - Yes, you need IPv6 Address on physical interface.+ Are the transitioning technologies (6to4, teredo, etc) set up automatically or separately? - I have personally not tested scenarios but i think it should set automatically on client machines, as they both have specific formatExample - Teredo IP will look like - 2001:0000::/32 & 6to4 IP will look like - 2002:WWXX:YYZZ:Subnet ID:Interface IDIPv4 - 65.222.166.37IPv6 - 6to4 - 2002:41de:a625::41de:a625+ I will request you to submit your feedback through online technet document, where you feel that information you were looking for is missing.Hope i have answered all your questions.

Thank you. I think that this clarifies alot. I have been doing some additional reading and i am beginning to grasp the concepts. It is definately much more complex than ipv4.I will try to post some comments on the technet doc. What i really would like to see is a Step by Step for setting up a small to medium business network for IPv6. From choosing a prefix, to setting up DHCPv6 scope and how to get the clients to obtain addresses from the server. The Understanding IPv6 book is very good providing atechnical understanding but it need some scenarios that talk you through setup.I guess that i should check out some webcasts on technet.I am working on this becausewe want to take advantage of DirectAccess when it is released for real. I am advocating upgrading all of our laptops to windows 7 to leverage DA for our travelers. IPv6 is a critical component of DA and i need to understand it better.Thanks again.