SYMPTOMS
In a SQL Server 2000 custom installation, if TCP/IP is the only selected protocol and all other protocols are disabled, SQL Server may not initialize and listen on TCP/IP sockets. The Server Network Utility shows that it is listening only on TCP/IP port 1433 even though it is not. Clients may fail to connect and the following error messages may occur:
Connection failed: SQL State: '01000' SQL Server Error: 11004
[Microsoft][ODBC SQL Server Driver][TCP/IP Sockets]ConnectionOpen (Connect()). Connection Failed: SQL State: '08001' SQL Server Error: 6 [Microsoft][ODBC SQL Server Driver][TCP/IP Sockets]Specified SQL server not found.
Unable to connect to server 'servername': Server: Msg 6, Level 16 state 1.
[Microsoft][ODBC SQL Server Driver][TCP/IP Sockets]Specified SQL server not found.
[TCP/IP Sockets]Specified SQL server not found.
[TCP/IP Sockets]ConnectionOpen (Connect()).
Note that the preceding error message can exist for TCP/IP connectivity problems other than this specific situation. To identify if SQL Server is not listening on TCP/IP, check to see if the value for
TcpPort in the following registry key is incorrectly set to blank or empty:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft SQL Server\
[Instance Name]\MSSQLServer\SuperSocketNetLib\Tcp\REG_SZ TcpPort=