Can't Install SCCM Primary Server

Question

On installing the Primary site, which connects to Central Server, I get the following error as "Attempted to perform an unauthorized operation"
I was not able to connect to WMI and all the required ports are open. The trust relation is also in place. 
Wondering if someone can help me troubleshoot the same. The following thing have been checked.
My id is added as member of administrator in CAS server
My id is added as sysadmin in the CAS SQL
MY id is set as Full Administrator in the SCCM Console.
Checked and confirmed port 445 and 135 is open between this SCCM server and the CAS Server
WMI connect gives the following error
Number: 0x800706ba
6) Taking the share on CAS server gives the error saying "System cannot contact a Domain Controller to service the authentication request. Please try again later"
However entering the local server privilege connects its later.
Any help will be greatly appreciated. 

Answer 1

Well, you don't really need a 'reason' to allow a primary site to connect to a CAS, you can do that regardless of the reason why.
Since you already have more than one primary site under the CAS, you should know the requirements for it. But ports are essential, but also admin rights to the CAS SQL Server. The TechNet docs should cover everything for you.
And, since the CAS already has child primary sites under it, this has to be a brand new primary site (not an expansion scenario). That is what you are implying.
The error code is "RPC Server is unavailable" so check that out also.
Wally Mead