I'm sorry. I lost the rules of ftp I insert when I setup the proftp.iptables -A INPUT 1 -p tcp -s 0/0 -d $HOME_ADDR --dport 8888 -j ACCEPT;) I can connect the ftp if I disabled the iptables. Otherwise, it wouldtimeout when cuteftp made a list.I enforced to use the PORT command , and it worked well.I think the command channel established, however, the require wasfiltered when the cuteftp make a data connection .So I want to knowwhether the iptables can resolve the promblem?