vsftpd and iptables

[J. Scott Amort]

On Tue, 2003-11-11 at 18:54, Christopher K. Johnson wrote:
> On an ftp server which you want clients to be able to access via passive 
> FTP be
> sure to insmod ip_conntrack_ftp module, which can be accomplished by 
> adding the
> following two lines to /etc/modules.conf
>  
> # iptables module added for passive ftp access to ftpd on local system
> above ip_conntrack ip_conntrack_ftp

Thanks very much - this worked.  However, I would like to know why? 
This wasn't a problem in RedHat 9 (or at least, it accomplished the same
thing a different way).  What exactly does this do?  Thanks again.

Regards,

Scott