When you install the FIM Synchronization service (FIM R2) , it fails with an error that it cannot connect to the SQL server. You can run into this error even when SQL is hosted on SQL 2008 R2 SP2
"Forefront Identity Manager Synchronization Service is having trouble contacting SQL server using the provided information. Please note that Forefront Identity Manager Synchronization Service requires Microsoft SQL Server 2008 SP1 or better. Verify the version, server and instance names as well as firewall settings and try again.”
Tips:
To verify that you can access the server via an ODBC connection
Go to: Administrator Tools --> Data Sources --> User DSN tab --> Add --> Fill in the server information --> Click "Test Connection"
use the telnet client to connect to the SQL server on the SQL port (default 1433)
telnet XX.XX.XX.XX 1433
The user that runs the installation needs to have sa permissions in the instance of SQL hosting the FIM Sync service. This is not necessarily the service account, the account running the sync service. It is the account performing the install.
Disable IESC for Administrators.
Verify the SQL Native Client is installed on FIM.
From FIM2010 Update 1 and forward FIM relies on the native SQL client, which is installed together with SQL server. Having a local SQL server will make sure this always works. FIM2010 RTM uses OLEDB, which comes with the operating system.
You can install the SQL native client from the SQL server CD. There is also a separate download from download center to install this component.
http://www.microsoft.com/en-us/download/details.aspx?id=6375
Microsoft SQL Server 2008 Native Client
Microsoft® SQL Server® 2008 R2 Feature Pack
http://www.microsoft.com/en-us/download/details.aspx?id=16978
Microsoft® SQL Server® 2008 R2 Native Client