How to set up active FTP when going through SOCKS on the ProxySG

Products

• Advanced Secure Gateway Software - ASG
• ProxySG Software - SGOS

Issue/Introduction

How to set up active FTP when going through SOCKS on the ProxySG?
FTP client is configured to use SOCKS.
The problem web site does not allow passive FTP connections.
How to force the proxy to use an active FTP connection instead of a passive FTP connection to the remote FTP server?
Active FTP works fine if the proxy is intercepting explicit or transparent FTP Proxy, just not when going through the SOCKS Proxy.

Resolution

Set the FTP client to use an active FTP connection instead of using a passive (PASV) FTP connection. Please note that the FTP client FileZilla will always try to go passive when configured to use a SOCKS proxy. As of the writing of this document, the FileZilla Client version is 3.39.0 Since FileZilla is an open source FTP client, this behavior may change with future releases.

ADDITIONAL INFORMATION:

The FTP Proxy is not supported on the ProxySG from the SOCKS Proxy. Unlike HTTP, IM, and SSL, there is no handoff from the ProxySG SOCKS Proxy to the FTP Proxy. If an FTP client connects via SOCKS to the ProxySG, the ProxySG's FTP Proxy will not be involved. Because there is no handoff, the ProxySG will not cache the FTP data, nor will it evaluate any of the FTP·related policy. The SOCKS Proxy will just TCP-tunnel the control and data connections through to the origin FTP server.