SQL Server Q&A

Symptoms
Consider the following scenario. On a client computer that is running Windows Vista orWindows Server 2008, you connect to a named instance of Microsoft SQL Server. The named instance is located on a remote server. In this scenario, the connection may fail.
Note This problem occurs when you connect to one of the following versions of SQL Server:Microsoft SQL Server 2000Microsoft SQL Server 2005Microsoft SQL Server 2008If you use Windows Data Access Components (Windows DAC) 6.0 to connect to the named instance, you receive the following error message:

[DBNETLIB]Specified SQL server not found.
[DBNETLIB]ConnectionOpen (Connect()).If you use SQL Native Client to connect to the named instance, you receive the following error message:

[SQL Native Client]SQL Network Interfaces: Error Locating Server/Instance Specified [xFFFFFFFF].
[SQL Native Client]Login timeout expired.This problem occurs when the named instance is a failover cluster instance. Additionally, this problem may occur if the remote server has multiple IP addresses.
Resolution
When you connect to the named instance, the client network library sends a User Datagram Protocol (UDP) request packet to the IP address of the named instance. Then, SQL Server Browser returns a UDP response packet that contains the information about the connection endpoints.
However, in the UDP response packet, the source IP address may not be the IP address to which the UDP request packet was sent. If the named instance is a failover cluster instance, the source IP address is the IP address of the physical computer instead of the virtual IP address of the remote server. If the remote server has multiple IP addresses, the source IP address may be any of the IP addresses that are assigned to the remote server.
In Windows Vista, Windows Firewall does not allow for loose source mapping. Therefore, Windows Firewall drops the UDP response packet.
For more information about loose source mapping, see the “UDP connections” section of the following Microsoft Web site:
http://technet2.microsoft.com/WindowsServer/en/library/3ccb6af5-d960-4a8d-b12b-70692dc47bf41033.mspx?mfr=true(http://technet2.microsoft.com/WindowsServer/en/library/3ccb6af5-d960-4a8d-b12b-70692dc47bf41033.mspx?mfr=true)

Symptoms
When you restore a database from a backup file by using SQL Server Management Studio in Microsoft SQL Server 2005 or in Microsoft SQL Server 2008, an incorrect backup set is listed in the Select the backup sets to restore list in the Restore Database dialog box.
Resolution
This issue occurs because SQL Server Management Studio generates an incorrect query when you restore the database. The query uses an incorrect condition to select backup sets. The condition does not implement the logic to enable restoring from an old recovery path to a new recovery path. The condition does not implement the logic of managing recovery forks that is described on the following Microsoft Web site:
http://msdn.microsoft.com/en-us/library/ms175078(SQL.90).aspx(http://msdn.microsoft.com/en-us/library/ms175078(SQL.90).aspx)