Description:

It enables the daemon to use the common tcpwrappers access control
library while in standalone mode, and in a very configurable manner.

Many programs will automatically add entries in the common allow/deny
files, and use of this module will allow a ProFTPD daemon running in
standalone mode to adapt as these entries are added. The portsentry
program does this, for example: when illegal access is attempted, it
will add hosts to the /etc/hosts.deny file.