Every day, more enterprises resort to the internet to provide their clients with access to their SQL Server 2000 databases, or to gain access to databases hosted at remote locations. This makes SQL Server 2000 increasingly prone to security attacks. As a result, Microsoft is constantly adding security features to prevent attacks and secure the popular database server. These features make connecting to SQL Server 2000 increasingly difficult to troubleshoot. One of the more common error messages users get is “SQL Server does not exist or access denied” or “Specified SQL Server not found”.
Follow these steps to help you determine the reason you cannot connect to SQL Server 2000:
- Verify that SQL Server or MSDE is installed and running (see SQL Server Installation Verification for details).
- If you are connecting remotely (to a server on a different machine), make sure your connection is not blocked by any firewalls on either machines including Windows built-in Internet Connection Firewall (ICF) and Windows Firewall. Contact your system administrator for firewall configuration.
- If you are referencing an instance of SQL Server 2000 or MSDE 2000 other than the default instance, use the convention <server_name><instance_name> (example ProdServSales).
- Make sure you don’t have an older ADO version.
- Make sure your client protocols are configured properly (see Client Network Utility for details).
- If you are connecting to a remote server and the server name is not resolved with DNS, use the IP address itself instead of the server name.
- Make sure that Windows XP SP2 is not blocking your connection (see Windows XP SP2 affects SQL Server and MSDE below).
Windows XP SP2 affects SQL Server and MSDE
Windows XP SP2 (for Home and Professional Editions) includes fixes and updates that resolve issues discovered since the last update. Windows XP SP2 also includes a set of Microsoft developed security technologies which were designed to help reduce the risk of malicious attacks against computer systems.
Windows XP SP2 includes Windows Firewall, an enhanced version of the component previously known as Internet Connection Firewall (ICF). Windows Firewall is a host-based, stateful, filtering firewall that discards unsolicited incoming traffic through TCP/IP version 4 (IPv4) and TCP/IP version 6 (IPv6) connections. Windows XP SP2 enables Windows Firewall on all network connections by default.
Windows XP SP2 will turn on the Windows Firewall by default. By turning on the Windows Firewall, computers are more resilient to attacks from worms similar to Blaster and Slammer.
SQL Server will have access to the local subnet by means of file and print sharing, which will enable access to named pipes, also known as multi-protocol, that use Port 445. TCP/IP and UDP will be turned off by default. Applications that connect to a SQL Server database by means of a network will not be able to accept or make connections. This setting change helps protect the customer system by making it resilient to malicious worms that send port requests to a computer in an attempt to create a denial of service attack. The application that is attempting to connect to SQL Server or MSDE will report a connection error.
If you have an earlier version of SQL Server with no updates installed, and then install Windows XP SP2, network access for that instance of SQL Server will be disabled, with only local access enabled. In this case, you will find an error entry in the Windows Error log that provides resources to help you update your version of SQL Server. Microsoft is taking this measure to help prevent worms such as Slammer from attacking unprotected computers. Microsoft recommends that customers use the most recent versions of products, with the latest service packs.
Effect on MSDE
Windows XP SP2 may affect the behavior of Microsoft SQL Server 2000 Desktop Engine (MSDE 2000). If you’re connecting to a network by means of TCP/IP, named pipes, or remote procedure call (RPC), the Windows Firewall will block the ability of the database to connect to the network. If you are using MSDE 2000 with SQL Server 2000 SP3a, you should not have a problem because the network and SQL Browser technology are already turned off by default.
In cases where your application needs to use TCP/IP or named pipes to access the network, we recommend that you set up access on an as needed basis. We also recommend that for TCP/IP, you use a static port assignment. For applications that use a named instance of MSDE with dynamic TCP port selection enabled, you can open the UDP port 1434 and the TCP/IP port as appropriate. For named pipes, we recommend that you use the Windows Firewall tool to open file and print sharing with Port 445 enabled. Microsoft does not recommend the use of multi-protocol to connect to SQL Server or MSDE.