FTP issues with Firewall-Friendly as default on Release 6.4.0

If you are on Release 6.4.0 and have applied APAR PI80912 (which is the Firewall-Friendly support), the default data transfer mode for the z/VM FTP client changes to passive data transfer. This means the FTP client will issue an EPSV command to ask an FTP server on what port the data connection should be opened. After receipt of the port number, the client will initiate the data connection prior to performing any data transfer.

Prior to this support, the default was for the z/VM FTP client to send a PORT (or EPRT) command to the FTP server, that indicated the port on which the data connection should be opened. Thus, the server would be the one that initiated the data connection.

If this new default causes problems with your FTP transmissions when using the z/VM FTP client, you can disable passive data transfer and switch back to doing active data transfer during your FTP session by issuing the following two LOCSITE commands: 

   LOCSITE NOFWF
   LOCSITE NOEPSV4
If you wish to change the default data transmission method that will always be used by the z/VM FTP client, you will need to add the following two lines to an FTP DATA file that is on an accessed disk: 
   FWFRIENDLY FALSE
   EPSV4 FALSE
Note: The Firewall-Friendly support provided by APAR PI80912 is included on RSU 1702.