The following errors might occur when you use SAS/ACCESS Interface to ODBC to connect to Microsoft SQLServer under Windows Server 2003. The errors occur when you perform many network connections simultaneously or within a short period of time.

ERROR: CLI error trying to establish connection: [Microsoft][SQL Server
Native Client 10.0]Named Pipes Provider: Could not open a connection to SQL
Server [5].  

ERROR: CLI error trying to establish connection: [Microsoft][SQL Server
Native Client 10.0]Login timeout expired 

ERROR: CLI error trying to establish connection: [Microsoft][SQL Server
Native Client 10.0]A network-related or instance-specific error has
occurred while establishing a connection to SQL Server. Server is not found
or not accessible. Check if instance name is correct and if SQL Server is
configured to allow remote connections. For more information see SQL Server
Books Online.

The problem occurs because Windows Server 2003 only allocates 5000 ports by default. When that limit is reached, especially over a short period of time, new connections experience a logon time-out. If named pipes are disabled at the server, the client machine might try the named pipes protocol in order to connect to the server. When this happens, the errors occur.

Possible solutions for these errors are as follows:

• Increase the number of ports by adding a registry entry for MaxUserPort. (See the appropriate Microsoft documentation for instructions on how to add this value.)
• Enable the named pipes protocol by using the SQL Server configuration manager. By doing this, the named pipes protocol can be used in the event that transmission control protocol (TCP) connections cannot be obtained.
• Use the CONNECTION=SHARED option in the LIBNAME statement to minimize the number of connections that are required by the SAS^® System.
• When you configure the ODBC data source name with the ODBC Data Source Administrator, add tcp as a prefix to the server name to force the client to use only TCP connections. For example, use tcp:sqlserver.sas.com for the server name.

Operating System and Release Information