To configure a report server to use Windows integrated security
Open RSReportServer.config in a text editor.
Find <Authentication>.
Copy one of the following XML structures that best fits your needs. You can specify RSWindowsNegotiate, RSWindowsNTLM, and RSWindowsKerberos in any order. You should enable authentication persistence if you want to authenticate the connection rather than each individual request. Under authentication persistence, all requests that require authentication will be allowed for the duration of the connection.
The first XML structure is the default configuration when the Report Server service account is either
NetworkService or LocalSystem:
<Authentication>
<AuthenticationTypes>
<RSWindowsNegotiate />
</AuthenticationTypes>
<EnableAuthPersistence>true</EnableAuthPersistence>
</Authentication>
The second XML structure is the default configuration when the Report Server service account is not NetworkService or LocalSystem:
<Authentication>
<AuthenticationTypes>
<RSWindowsNTLM />
</AuthenticationTypes>
<EnableAuthPersistence>true</EnableAuthPersistence>
</Authentication>
The third XML structure specifies all of the security packages that are used in Windows integrated security:
<AuthenticationTypes>
<RSWindowsNegotiate />
<RSWindowsKerberos />
<RSWindowsNTLM />
</AuthenticationTypes>
The fourth XML structure specifies NTLM only for deployments that do not support Kerberos or to work around Kerberos authentication errors:
<AuthenticationTypes>
<RSWindowsNTLM />
</AuthenticationTypes>
Paste it over the existing entries for <Authentication>.
Note that you cannot use Custom with the RSWindows types.
Save the file.
If you configured a scale-out deployment, repeat these steps for other report servers in the deployment.
Restart the report server to clear any sessions that are currently open.
Thats it ..........