Enable FTP: ip_nat_ftp and/or ip_conntrack_ftp?

[linux at fritzenwallner.org]

Hi!

I'm working on a RHEL WS3, Taroon Update 5 and have the following problem:
I installed the ftp-server "vsftpd-2.0.3" as a xinetd based services and would
like to get it working.
I opened the firewall on FTP using redhat-config-securitylevel. Then I could
connect to my machine but "ls" didn't work (No route to host).

Then I googled a little and found out that it might be needed to load an
additional module which can be added to the file /etc/sysconfig/iptables-config.
So I loaded from the command prompt the module ip_conntrack_ftp with the command
"modprobe ip_conntrack_ftp", ....and FTP works now!
Additionaly I found out that if I load the module "ip_nat_ftp", FTP works as well.

Now I don't know which module I should add to the file 'iptables-config', only
one of them or both, ip_nat_ftp and ip_conntrack_ftp?

What are these modules for?


Thanks very much for your help!
Marcel Fritzenwallner