Use passive ftp
Linux IP NAT Forum
NAT and FTP (John Turnbull)
Keywords: FTP, NAT
Date: Wed, 09 Sep 1998 03:07:15 GMT
From: Brian Beuning <firstname.lastname@example.org>
Passive mode ftp was designed to get around the nasty
part of the ftp protocol that confuses MASQ and firewalls.
Since we set up a firewall, we have been using passive
mode exclusively and not found any ftp sites which do
not support passive mode.
Passive ftp by John Turnbull, 9/10/98
PASV Mode Problems w/ Firewalls by Arne Kuhlmann, 11/04/98