DB2 Version 9.7 for Linux, UNIX, and Windows

ServiceName CLI/ODBC configuration keyword

The server system's service name or port number, used with file DSN or in a DSN-less connection.

db2cli.ini keyword syntax:
ServiceName = service name | port number
Default setting:
None
Only applicable when:
Protocol set to TCPIP
Usage notes:
 

Use this option in conjunction with the Hostname option to specify the required attributes for a TCP/IP connection from this client machine to a server running DB2®. These two values are only considered when the PROTOCOL option is set to TCPIP.

Specify either the server system's service name or its port number. The service name must be available for lookup at the client machine if it is used.