BUG: "Unable to Connect" Msg May Occur in Application Event Log

• Microsoft SQL Server, versions 6.0 and 6.5

SYMPTOMS

Under certain situations, one of the following errors may be logged by SQL Server in the Application Event Log:

• Severity: 9 Error:10004, OS: 11001 Unable to connect: SQL Server is unavailable or does not exist. General network error. Check your documentation.ConnectionOpen (gethostbyname()()).

  -or-

• Severity: 9 Error:10004, OS: 252 Unable to connect: SQL Server is unavailable or does not exist. General network error. Check your documentation.ConnectionOpen (ReadPropertyValue()).

CAUSE

By default, the xp_sqlregister extended stored procedure is run automatically at SQL Server startup. If the default client Net-Library on the server is set to non-named pipes IPCs such as TCP/IP or IPX/SPX, you would see this error message in the Windows NT Server Event Viewer. This error message occurs when this particular extended stored procedure tries to log on to SQL Server using dot "." as the local server name. This fails because dot "." is not valid as the local server name under non-named pipes IPCs.

WORKAROUND

Do not set the default Net-Library to non-named pipes IPCs on the server. Because the setting of a default client Net-Library on the server does not affect how other clients connect to SQL Server, you should never have to set the default Net-Library on the server to anything other than named pipes. If you need to connect to other SQL Servers from this server using non-named pipes IPCs, you can always do so through advanced entries in the client configuration. For more details, see the SQL Server the Books Online.

STATUS

Microsoft has confirmed this to be a problem in Microsoft SQL Server versions 6.0 and 6.5. We are researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.