I have a 2008r2 dc with all the roles in a 2003 forest/domain. From the 2003 sp2 dc servers I cant add the dns server for the 2008r2 dc However from the 2008R2 server I can add the 2003 servers in. The error I receive when I type the fdqn is access denied. If I dont type the fqdn i get the server is unavailable. would yuou like to add anyway? NSlookup works and no errors in the logs. Thanks,

Hi, take a look a this thread http://www.eggheadcafe.com/software/aspnet/32571399/cannot-manage-windows-server-2008-server-core-install.aspx HTHEdoardo Benussi - Microsoft MVP Management Infrastructure - Systems Administration https://mvp.support.microsoft.com/Profile/Benussi Windows Server Italian Forum Moderator edo[at]mvps[dot]org

Hello Mrod322, Please run the following commands on each DC and upload log files to SkyDrive for troubleshooting. -> IPCONFIG /all > c:\ipconfig.txt -> DCDIAG /V /C /D /E /s:yourdcname > c:\dcdiag.log Brent Hu,Please 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.

Hi Brent, I think that Windows Firewall on Windows Server 2008 R2 could prevent comunication between DNS MMC on Windows Server 2003 and DNS Server on Windows Server 2008 even if DNS replication work fine.Edoardo Benussi - Microsoft MVP Management Infrastructure - Systems Administration https://mvp.support.microsoft.com/Profile/Benussi Windows Server Italian Forum Moderator edo[at]mvps[dot]org