Error Message:

Couldn't establish the establish database connection. Unknown server host name.

Possible Cause:

1. Database is offline.

2. Renamed database files.

3. Moved the database to a new server.

4. Correct ODBC version is not installed on the AD Manager hosted server.

5. The SQL Server instance is not accessible due to firewall or some other reasons.

1. Verify whether the SQL Server service is running on the server and attempt to login into the server.

2. Verify whether the database is online in the SQL server.

3. Install or update the correct version of ODBC driver in the AD Manager plus hosted machine.

4. Determine the server's IP address and then attempt to PING the SQL server using IP address or the server name (DNS name) from Command Prompt.

5. If a Windows firewall is running on the workstation or server, verify whether the correct port number is opened in the firewall. Your port 23001 and UDP port 1434 of SQL server browser should be enabled.

6. Ensure to enable TCP/IP and named pipes. You can find these in SQL Server Configuration Manager in the left pane.

7. If necessary, you have to enable remote connections to connect to the databases remotely.

• To do this, right-click the SQL server instance name available in the Object Explorer window of the SQL Server Management Studio.

• Select Properties.

• In the subsequent window that pops up, click Connections from the left pane and under Remote server connections and check the Allow remote connections to this server box.