Hello, I have Windows 2003 domain controllers hosting DHCP Servers in our Windows domain. I have installed Windows 2008 R2 as additional domain controller and I like to create a new DHCP scope in IPv4 format. Our network is not IPv6 ready and I prefer not to run services I don't use because of security concerns. I have read and heard mixed reactions from Microsoft community and Microsoft engineers about IPv6. Some say don't disable IPv6 on Windows 2008/ R2 as this could create issues for Microsoft latest releases like Exchange 2010, SQL 2008 R2 etc. I am not sure how this will be a problem if the infrastructure/ network doesn't support IPv6 protocol. 1. What's Microsoft recommendation on IPv6 for environments that support IPv6? Disable if not using or keep it enabled (enabled by default) 2. I am configuring DHCP on Windows 2008 R2 for IPv4. NIC on this server has IPv6 enabled but doesn't have a static address. Is it safe to uncheck IPv6 from NIC properties. I would assume Microsoft not recommending having this interface running with a dynamic address for IPV6 and static address for IPv4. To brief it, if I am not using IPv6 , can i disable it and will it cause any issues in future with products like Exchange 2010, SQL 2008 R2 etc. Thanks in advance

Hi, Thanks for the post. We recommends that you leave IPv6 enabled, even if you do not have an IPv6-enabled network, either native or tunneled. By leaving IPv6 enabled, you do not disable IPv6-only applications and services (for example, HomeGroup in Windows 7 and DirectAccess in Windows 7 and Windows Server 2008 R2 are IPv6-only) and your hosts can take advantage of IPv6-enhanced connectivity. For more informattion, please check the following article: http://technet.microsoft.com/en-us/magazine/2009.07.cableguy.aspx Here is another post regarding the same issue you could refer to: http://social.technet.microsoft.com/Forums/en-US/windowsserver2008r2networking/thread/d7bfc3f0-1ea7-43e9-aaae-7b1d5c0b5c51 Hope this helps. MilesPlease remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

Thanks Miles for your post. This brings up another question. Is it recommended to leave IPv6 enabled with dynamic address on a Server installation?For example, in my case I configured a Windows 2008 R2 Server as additional domain controller. This server will act as an internal DNS Server (AD integrated) and DHCP Server. So how could leaving IPv6 enabled with dynamic address a best practice? Also, during DHCP installation a window pops up with warning saying " A dynamic address for IPv6 detected, please use a static address" which is what I would expect for Servers. I am not worried about desktop part, this could be left enabled but on Server side is it a big security hole to leave it enabled? Is there a Microsoft KB article where Microsoft express their recommendation for an environment with no IPv6 SUPPORT? Thanks in advance

My apologies Miles, I saw Microsoft's recommendation from the link you included in the post. To be specific, if I leave IPv6 enabled on the Server, while configuring DHCP it adds a IPv6 Scope. So it will be DHCP Server Name | IPv4 (Scope will be configured here) | IPv6 (No scope configured, but appear with a GREEN check mark) Can I assume this to be safe or what is MSFT recommendation? Thanks in advance

Hi, Thanks for the update. It will be safe if we don't add a IPv6 scope for the DHCP server. Thanks, MilesPlease remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.