Ich vermute da hilft dies: (Release ab R610)
Disabling EPASV/EPORT in the iSeries FTP Client at R610
Technote

At R610, the iSeries FTP client supports the EPASV (Extended Passive, EPSV) command and EPORT (Extended Port, EPRT). The FTP client defaults to this and if the server we are connecting to does not, the FTP client will fail over to Passive mode FTP. However, in some cases, an error message is not returned. Most commonly, this is due to a firewall not allowing or supporting the EPASV /EPORT command, and the establishment of a data connection will appear to 'hang'. In these cases, the EPASV /EPORT commands must be disabled.

The FTP client attempts data connections in the following manner:

Extended Passive
Passive
Extended Port
Port

As a result, if PORT mode is needed, the three preceding data connection types must first be toggled off. This can be done in one of two ways:

1. On a connection by connection basis using FTP client subcommands:

o SENDEPSV - Toggles off Extended passive
o SENDPASV - Toggles off Passive mode
o SENDEPRT - Toggles off Extended Port

2. On a system-wide basis with the use of data areas:

o CRTDTAARA DTAARA(QUSRSYS/QTMFTPEPSV) TYPE(*LGL) AUT(*USE) - disables EPASV
o CRTDTAARA DTAARA(QUSRSYS/QTMFTPPASV) TYPE(*LGL) AUT(*USE) - disables PASV
o CRTDTAARA DTAARA(QUSRSYS/QTMFTPEPRT) TYPE(*LGL) AUT(*USE) - disables EPO RT with PTF SI33243 applied to the system.