Resolving SSRS windows authentication issue, continuous pop up of user authentication dialog and the user never gets authenticated.

Recently there has been a issue where in a test environment, one of my colleagues was having a scaled out setup of SSRS. He had dedicated virtual servers for Database, SSRS and SharePoint (SSRS was installed in SharePoint Integrated mode). After the installation he could connect to the Report Server using the default url within the same server where SSRS was installed. However, from any of the other servers, Database and SharePoint, this was not possible, as when accesses the url, the user authentication dialog continuously pops up and it never gets authenticated even though the user name and the password was confirmed to be correct.

After hours of struggling, it turned out that the issue was with the authentication settings of SSRS in the Reporting Services Config file. The below link can be used as a guide to do this.

http://technet.microsoft.com/en-us/library/cc281253.aspx