Probable cause: “-f” parameter ignored and its “filename” operand treated as a “hostname” parameter.
Explanation: For z/OS releases prior to 1.8, the “-f” parameter is unsupported. Because it is unsupported, it is ignored. But the “filename” operand is not ignored. It is assumed to be a “hostname”. Because it is not really a hostname, the attempt to establish a connection with an FTP server at that host must fail.
Action: The user should remove the “-f filename” parameter from the JCL PARM and rerun the job.