On 10/5/07, Feizhou feizhou@graffiti.net wrote:

...

Do you have ip_nat_ftp loaded too?

YES, both ip_conntrack_ftp and ip_nat_ftp. pls see below

#Enable tracking mechanism /sbin/modprobe -a ip_conntrack_ftp ip_nat_ftp

Hmm, I think the NEW for port 1024: is not necessary in FORWARD then. The nat_ftp should handle it and thus make it ESTABLISHED,RELATED and the ESTABLISHED,RELATED rule should therefore be sufficient.

That meas I do not nedd below rule i FORWARD chain.

iptables -A FORWARD -p tcp -d 192.168.100.3 --dport 1024: -m state --state NEW -j ACCEPT

So below 3 rules will be enough.

iptables -t nat -A PREROUTING -p tcp -i eth0 -d 1.2.3.4 --dport 21 -j DNAT --to-destination 192.168.100.3:21 iptables -t nat -A PREROUTING -p tcp -i eth0 -d 1.2.3.4 --dport 1024: -j DNAT --to-destination 192.168.100.3

iptables -A FORWARD -p tcp -d 192.168.100.3 --dport 21 -m state --state NEW -j ACCEPT