Here's my experience on actively contributing in the resolution of a problem related to Active FTP & gnu-linux/ip-tables based firewall solution. First, make sure your firewall has loaded the following modules: ip_conntrack_ftp ip_nat_ftp Then check that the right Forwarding rules apply: iptables -I FORWARD -m state --state ESTABLISHED,RELATED -j ACCEPT being "RELATED" the important part.… Read More