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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.

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up vote 2 down vote accepted

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

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