How to authenticate SSRS externally using automatic NTLM credential passing?

Question

I am attempting to set up our SSRS server to authenticate over the internet using user entered NTLM credentials with the Automatic Logon setting in IE.

The result so far has been the generic 'Internet Explorer Cannot Display the Webpage' error when attempting to navigate to the report manager or report server. I am not getting much relevant information off of google.

Has anyone else encountered this edge case? Any suggestions?

Answer 1

SSRS will fail to authenticate over the internet with automatic NTLM credential passing if the <RSWindowsNegotiate/> authentication type is present in the <Authentication> section of the rsreportserver.config file.

Comment out the <RSWindowsNegotiate/> Authentication Type to resolve this issue.

(C:\Program Files\Microsoft SQL Server\MSRS10_50.MSSQLSERVER\Reporting Services\ReportServer\rsreportserver.config)

    <Authentication>
    <AuthenticationTypes>
    <RSWindowsNTLM/>
    <!-- <RSWindowsNegotiate/> -->   
    </AuthenticationTypes>
    <RSWindowsExtendedProtectionLevel>Off</RSWindowsExtendedProtectionLevel>
    <RSWindowsExtendedProtectionScenario>Proxy</RSWindowsExtendedProtectionScenario>
    <EnableAuthPersistence>true</EnableAuthPersistence>
    </Authentication>