Unable to open Application database.

[DBNETLIB][ConnectionOpen (Connect()).]SQL Server does not exist or access denied

The client computer is failing to initiate a successful connection to SQL Server.

Normal

• Firewall on the server computer or network is blocking access to SQL Server.
• Improper configuration of SQL client protocols.
• DNS issue where the client is not properly resolving the computer name to the proper IP address of the server.

• ===Configuration of SQL Server Protocols===
  • From the server, navigate to Start | All Programs | Microsoft SQL Server | Configuration Tools | SQL Server Configuration Manager.
  • Expand the SQL Server Network Configuration section. Click on the Protocols section for the SQL Instance used by Cyrious.
  • Ensure Shared Memory, Named Pipes, and TCP/IP are enabled.
  • Discretionary Configuration of TCP/IP. At times due to firewall or other network related settings you may have to bind SQL Server to a static port so that you can enter exclusions in the firewall to allow SQL server communication across the network.
    • To set a static port, follow the steps above then double click on TCP/IP Protocol to open the Properties window, click on the IP Addresses tab.
    • Locate the entry for TCP Dyanmics Ports and erase everything from that field for each occurrence that you find in the IP Addresses tab.
    • Locate the entry for TCP Port and specify 1433 in each occurrence that you fiend in the IP Addresses tab.
    • Note: If you have multiple versions of SQL Server installed you may receive a port binding error if another SQL instance has already been configured to operate on this port. If that occurs you can specify a different port, such as 4299 to utilize for SQL communication. An alternate option is to disable the other SQL instance if it is not being utilized by any applications.
  • Once you have completed your changes to the SQL Server Network Configuration you must restart the SQL Server service to apply the changes. You can do so by using the Services.msc snap-in under Control Panel | Administrative Tools | Services.
• ===Check Configuration of SSLIP===
  • Database Administration > Store Data > ServerName: SERVER\CYRIOUS INSTANCE,1433
  • Try adding the SSLIPAddress option to the Control_Options.txt file (ex: SSLIPAddress=servername)
• ===Configuration of DNS===

• If the computer name of the server is not resolving to the proper IP address actually set on the server then you are having a name resolution problem. This is typically caused by improper DNS settings in the network adapter settings on the client computer, improperly configured DNS server, DNS Registration problems, and router issues. To test if this is occurring:
  • Ping the server from the client by opening a Command Prompt (Start | Accessories | Command Prompt)
  • Type ping at the command line prompt. Please substitute the actual computer name of the server in place of the text. During the ping an IP address should be returned. Check that IP address against the actual IP Address on the server.
  • From the server open a Command Prompt. Type IPConfig /ALL. If the IP address returned does not match the IP address shown on the client machine you have confirmed the existence of a DNS issue. You can attempt to flush the DNS on the client by typing IPConfig /Flushdns at a command line prompt. Ping the server again from the client to see if the proper address is now resolving
  • Rebooting the network router and computers can sometimes resolve this problem, ultimately you may need to consult a network technician to identify the cause of the problem and long-term resolution.
  • Check the Hosts file in C:\Windows\System32\Drivers\Etc\ has not been modified by someone. At times network technicians will manually set what IP address a computer name should resolve to when queried. If that IP address changes this file will not see the change and cause an ongoing problem with connectivity.
• ===Configuration of SQL Client Protocols===
• Click on Start | Run | Type cliconfg on the client computer.
• Enable the following SQL Server protocols: Multiprotocol and TCP/IP.
• Check Enable shared memory protocol
• Ensure Force protocol encryption is not checked.
• Ensure that TCP/IP has priority (make sure it appears first in the list in the box “Enabled protocols by order:”)
• ===Configuration of Firewall===
• Configure SQL Server to operate on a static TCP/IP port. By default, the recommended port is 1433.
• Configure the firewall to allow incoming/outgoing traffic on port 1433 on the server.
• Check specifically to ensure that SSLIP is allowed on 1433 as well.

Creating an ODBC connection from the client computer to the server computer will help you determine the type of connectivity problem you're encountering. If an ODBC connection is unsuccessful it may point to a SQL communication protocol, SQL Port, or Firewall issue.

• Create an ODBC connection from the client to the server to test the connection to the database on the server. You can create an ODBC Connection under Control Panel | Administrative Tools | Data Sources (ODBC).
• Click on the System DSN tab and click the Add button.
• Select SQL Server when prompted to Select a driver for which you want to set up a data source then click the Finishbutton.
  • Type Cyrious in the Name field.
  • Type ComputerName\SQLInstanceName in the Server: field substituting the actual computer name and SQL instance name from the server then click Next.
  • Select With SQL Server authentication using a login ID and password entered by the user
  • Type Cyrious in the Login ID: field.
  • Type the proper password in the Password: Field and click Next.
• If the ODBC connection fails to connect, click the Client Configuration button and uncheck Dynamically determine port. Set the port to 1433 and click Next again.
• If you are able to successfully initiate a ODBC connection verify through Control as well.

• Entered : 7/13/2010