HTTP Error 401 – Not Authorized Error in SharePoint site with Kerberos Authentication Enabled
In a new SharePoint web application, it prompted for user name and password repeatedly
And finally resulted in “Not Authorized – HTTP Error 401. The requested resource requires user authentication” – in the SharePoint site with Kerberos Authentication Enabled.
Here is some more spec: MOSS 2007, Windows 2008, IIS 7.5.
With IIS 7.5, Kerberos enabled for SharePoint, we must turn OFF the “Kernel Mode Authentication”. Here is how:
1. Open the IIS, Select the authentication feature of the appropriate web application
2. Select the authentication mode which is enabled, click on Advanced settings
3. Make sure you have unselected the “Kernel Mode Authentication”
4. Do an IISReset