We have a tomcat application running on Windows Server 2008 R2 that connects to SSRS 2008 using NTLM authentication, but fails to authenticate and show Authentication error 401. We have no problem with NTLM authentication if SSRS is running on Server 2003. Is there any way I can disable NTLMv2 on Server 2008 and use NTLMv1? I have tried disabling NTLMv2, editing some local security policies, disabling ipv6, but still out of luck. Hope anyone can advice. Thanks!

You must edit group policy as shown here: By default Windows Server 2008 R2 sends NTLMv2 response only. Edit specified setting to allow NTLMv1.My weblog: http://en-us.sysadmins.lv PowerShell PKI Module: http://pspki.codeplex.com Windows PKI reference: on TechNet wiki

Hi Vadims, I already set that too, however still failed. I also installed SP1 for 2008 R2 but still no luck.

In particular here is the error message that I only encounter if I connect to a SSRS on Server 2008. But if I point the apps to use SSRS on Server 2003, it works. Very frustrating error, what have they done to NTLM on 2008. I hope someone can shed a light.

Have you tested setting the NTLM minimum session security http://technet.microsoft.com/en-us/library/dd566199(WS.10).aspx /Hasain

Hi Hasain, Yes, in the image I posted above you can see that I already set both to no minimum.