proftpd

It's not quite as clean as the socket binding under Apache but the principle works something like this.

1. In Standalone mode, to listen on the primary IP of a host use the SocketBindTight directive.

   In "/etc/proftpd.conf":

   SocketBindTight                 on
   

2. To listen on a interfaces which are not the primary host interface, use the SocketBindTight directive, place your server configuration in a block and use "Port 0" for the main host configuration and and "Port 21" inside the VirtualHost block.
   Port                            0
SocketBindTight                 on
<VirtualHost xxx.xxx.xxx.xxx>
        Port 21
        DefaultRoot             ~
        AllowOverwrite          on
        Umask                   002
</VirtualHost>

Recently I've had to research on some missing files of a website.

When looking through the proftpd xferlog files, it was clear that the files were deleted by a user having ftp access.

The xferlog file is usually located at "/var/log/xferlog". However, since this was a plesk server, it was located at:
"/var/www/vhosts/{DOMAIN}/statistics/logs/xferlog_regular*"

A quick grep produced the files that were deleted out and could easily be recovered from a previous backup. Also, discovered the time and offending IP address of the person that did the deletes.

Full listing:

Listing of just the deleted files:

Below are some additional notes on xferlog anlysis: