If you are using this "look and feel"
The Reflection Ribbon
On the Session ribbon, from the Transfer group, click the Transfer Settings launcher:
The Reflection Browser
On the Reflection menu, choose Tools and then File Transfer. In the Transfer dialog box, click the Settings button.
The options are:
Type the host system address here if you do not have a Hosts file, and your system name does not have an IP address entry in the Domain Name Server for which your TCP/IP stack is configured.
Use default ports
Clear this check box to allow Reflection to communicate with host transaction programs using non-standard port numbers.
AS/400 Tab (Transfer Settings Dialog Box)