ftp nat MAX PORTS

[iansolo <iansolo.netfilter@betisgroup.com>]

Hi All,
I've a problem with ftpserver behind a NAT.
My necessity is to run ftpserver in a different port then 21.
This is the situation:

Router
|
Firewall
|
Ftpserver

I use this modules ad pass these parameters :

/sbin/modprobe ip_tables
/sbin/modprobe ip_conntrack
/sbin/modprobe ip_conntrack_ftp ports=21,9000
/sbin/modprobe iptable_nat
/sbin/modprobe ip_nat_ftp ports=21,9000
/sbin/modprobe ipt_MASQUERADE
/sbin/modprobe ipt_state

The realtive iptables rules are only these:

$IPTABLES -t nat -A PREROUTING -p tcp -d $EXT_LAN_FW --dport 9000 -j NAT 
--to-destination $IP_FTPSERVER:9000
$IPTABLES -A FORWARD -i $EXT_IF -p tcp --dport 9000 -j ACCEPT -d 
$IP_FTPSERVER

Unfortunately don't work!


VERY IMPORTANT :

- All work fine is the port is 21!!

- When I try to connect with my ftp-client(with port 9000), at a certain 
point I tray to send packets to local IP of firewall ($EXT_LAN_FW).....

Others Questions:

- In the source code of ip_conntrack_ftp there is a variable "MAX_PORTS",
but I don't understand what mean...
- What is "Patch-O-Matic" ?


Thanks a lot in advance!
iansolo

ps: excuse me, my English is poor