ISPConfig ProFTPD changes?

I have been having a hard time getting ProFTPD to work on a clean install (My previous post: http://www.howtoforge.com/forums/showthread.php?t=435&highlight=proftpd).

I installed CentOS with minimal configuration and installed ProFTPD from Dag Wieers RPM repository for APT and still could not get it working. As soon as I continued with the install (following this guide - http://www.howtoforge.com/forums/showthread.php?t=470), ProFTPD worked.

What changes does ISPConfig make to get ProFTPD to work? Or what else is installed in the setup to get ProFTPD to authenticate?

 

It just adds

Code:

Include /etc/proftpd_[IP_ADDRESS].conf

to /etc/proftpd.conf (and creates the included file... ).

 

So... what exactly does that do? How is that critical to ProFTPD's fuctionality?

 

It just adds functionality so that Anonymous FTP is available for _each_ IP address on the server.