Windows line command ftp doesnt have "PASV" feature. So you cant go to Passive mode.


On Netfilter (a.k.a. iptables) you must activated statefull inspection, using -m state --state tags.

I dont know on RH, but connection track must be loaded to statefull works for ftp.

Your symptom is: ftp-control session works (client--->server) but ftp-data doesnt (on active ftp is server side started)

On netfilter website (www.netfilter.org) is a good tutorial about ftp

or here:
http://slacksite.com/other/ftp.html#intro
http://www.sns.ias.edu/~jns/security...track.html#FTP