Sql-server – Problems connecting to SQL Server using ODBC

dsnodbcsql server

Since three days ago I have problems connecting to SQL Server on a local network using our Access based application which uses linked tables. It happened suddenly and it only happens on my PC which I use for development. All other clients on the network can connect as usually. I tried to create new DSN connections using the following drivers: "SQL Server", "SQL Server Native Client 11.0", "ODBC Driver 11 for SQL Server". None of these can establish successful connection. I searched a lot on the Internet and tried various options, but none worked. I checked and disabled the firewalls on the server and my PC. I can connect to the old SQL Server on the same network on another PC. I tried to create another server instance, but it didn't help. I can connect through SSMS. When I try to create a new DSN connection, the server name is listed in the dropdown box.

Here are some errors that I have faced while trying to establish the connection:

Connection failed:
SQLState: '08001'
SQL Server Error: 0
[Microsoft][SQL Server Native Client 11.0]Unable to complete login process due to delay in opening server connection

Connection failed:
SQLState: 'HYT00'
SQL Server Error: 0
[Microsoft][ODBC SQL Server Driver]Login timeout expired

Connection failed:
SQLState: '01000'
SQL Server Error: 10061
[Microsoft][ODBC SQL Server Driver][TCP/IP Sockets]ConnectionOpen (Connect()).

Connection failed:
SQLState: '08001'
SQL Server Error: 17
[Microsoft][ODBC SQL Server Driver][TCP/IP Sockets]SQL Server does not exist or access denied.

Connection failed:
SQLState: '08001'
SQL Server Error: 10061
[Microsoft][SQL Server Native Client 11.0]TCP Provider: No connection could be made because the target machine actively refused it.

Connection failed:
SQLState: 'HYT00'
SQL Server Error: 0
[Microsoft][SQL Server Native Client 11.0]Login timeout expired

Connection failed:
SQLState: '01000'
SQL Server Error: 11001
[Microsoft][ODBC SQL Server Driver][TCP/IP Sockets]ConnectionOpen (Connect()).

Connection failed:
SQLState: '08001'
SQL Server Error: 6
[Microsoft][ODBC SQL Server Driver][TCP/IP Sockets]Specified SQL server not found.

Thank you in advance.

Best Answer

At a quick glance, looks likely to be a delay caused by DNS hostname lookup. I'd try setting the target hostname to its IP address, and retest.