Problem:

If like me you are trying to add a CNAME alias to an existing computer so you can access it via two different DNS names and you receive the message “You Were not connected because a duplicate name exists on the network. Go to System in Control Panel to change the computer name and try again”. Then read on

You Were not connected because a duplicate name exists on the network. Go to System in Control Panel to change the computer name and try again

 

Solution for Server 2000, 2003, 2008:

  • First in DNS create a CNAME record instead of a normal Host(A) record.
  • The next thing to do is to create a new DWORD key in the registry, On the server open regedit and navigate to;

 

  • Create a new DWORD with the following details:

  • Then reboot the server.

Solution Server for 2008 R2 (and higher):

  • First in DNS create a CNAME record instead of a normal Host(A) record.
  • The next thing to do is to create a new DWORD key in the registry, on the server open regedit and navigate to;

  • Create a new DWORD with the following detail;

  • Next on server create SPN’s for the flat name and the fully qualified name matching your CNAME alias, open up a command prompt and run the below;

  • Then reboot the server.

References:

http://support.microsoft.com/?id=281308

http://www.clydesdalesoftware.com/blog/10-02-25/CNAME_rsquo_s_and_SPN_rsquo_s_Access_Denied_Error.aspx