Issue with JDBC SQL Database Connector

Hope someone can help me. I've used the SQL Server JDBC driver a couple of times now but have run into a problem. I'm getting an error when trying to connect to a client's SQL database. We are running KNIME on the same Server as the SQL instance. Windows Firewall has been disabled for the domain. The error I'm getting is:

ERROR Database Connector   0:2        Execute failed: Could not create connection to database: The TCP/IP connection to the host HostName, port 1433 has failed. Error: "Connection refused: connect. Verify the connection properties. Make sure that an instance of SQL Server is running on the host and accepting TCP/IP connections at the port. Make sure that TCP connections to the port are not blocked by a firewall.".

The client's IT department assures me that the port isn't being blocked. Has anyone else run into similar issues. 


Is it possible that your SQL Server has been configured for TCP/IP connection to a different port than the default one 1433? Please see here: