Disabling EPASV/EPORT in the iSeries FTP Client at R610 and above

Resolving The Problem

This document describes how the EPASV (extended passive) command can be disabled in the iSeries FTP client.

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.

229 Entering Extended Passive Mode

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

Note: The data connection type can also be set (regardless of what the default behavior is) by using the 0 or 1 switches with the above 3 commands. For instance:

SENDEPSV 1 - would toggle extended passive on
SENDEPSV 0 - would toggle extended passive off

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 EPORT with PTF SI33243 applied to the system - no ptf is needed for releases after R610.