I am currently trying to upgrade my two WFEs from 32 bit Windows Server 2003 to 64 bit Windows Server 2008. I also have a 64 bit Windows server 2008 in the farm as an index server, and a 64 bit SQL 2005 box running Windows server 2008. I am using kerberos authentication to allow for smart card auth on the ISA 2006 server.

After upgrading one of the front ends I am unable to access it through ISA. I get the multiple prompts even though I am entering valid credentials. When looking in the sever logs there are numerous kerberos errors referencing a null sid.

Does anyone else have this configuration working? and if so please help.

1 Answer 1


You are probably having problems with the new "feature" in IIS 7 - Kernel Mode Authentication

Kernel Mode Authentication uses the SPNs on the computer account, even if the application pool runs on a different service account. This is a problem when you are running a Sharepoint farm with more than one frontend webserver


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.