Thursday, April 16, 2009

Disable Loopback Checking on Windows Server 2003

I updated my Windows Server 2003 running on a VMware image with the lasted April 2009 updates from Microsoft this morning. The result was that none of my SharePoint sites worked afterwards. The solution for me and one of my colleagues turns out to be this old known issue
http://wcornwill.wordpress.com/2006/06/06/mapping-host-headers-causes-looping-windows-authentication/
and
http://www.sharepointblogs.com/george/archive/2009/04/16/error-401-connecting-to-local-iis-website-after-3-credential-prompts.aspx

I would only recommend to disable the Loopback checking for developing environments.

Disable Loopback Checking

  1. open regedit
  2. Find HKLM\System\CurrentControlSet\Control\Lsa
  3. Create a new DWORD value called DisableLoopbackCheck and give it a value of 1
  4. Restart the computer


2 comments:

Brian Kenneth Nielsen said...

Hi Carsten

Yes.. seems that a lot of solutions is having this problem, if the they run on a single server.

/Brian

Anonymous said...

I think this should also be done to all servers in the farm otherwise you will not be able to access any virtual server from the local machine... at least when using host headers.