There are a few other "traditional" FTP configuration files that NcFTPd honors.

There is the /etc/ftpusers file, which lists usernames that should not be allowed to login via FTP.  This simple security measure lets you ensure that certain accounts can never login from FTP, even if a valid username and password were given.  This is desirable for accounts that aren't really live user accounts, such as bin or uucp.

This file is a list of usernames, one per line.  The file is loaded only once, when NcFTPd starts up, so if you need to add users you will need to restart NcFTPd for the changes to take effect.

If you want to use this feature, set u-deny-users-file to the name of the file with the forbidden user names. You are encouraged to use the filename /etc/ftpusers which is recognized by other programs for this purpose.

For a host attached to an insecure network (i.e. the Internet), I highly recommend placing the root user in this file.  Generally there should not be FTP activity for the superuser, except in controlled, internal environments.

Note: Whenever you make changes to /etc/ftpusers, you need to restart NcFTPd.

Note: If the user ftp appears in the file, anonymous user access will not be allowed. The preferred way to deny anonymous access is to use the server-type option, so do not add ftp to this file (or remove ftp from the file if it was already present).

Note: Virtual users (in NcFTPd password databases) are not affected -- if you want to deny a user in a password database, you must delete the user record from the database.

Here's an example /etc/ftpusers file:

root
bin
daemon
adm
lp
sync
shutdown
halt
mail
news
uucp
operator
games
nobody

u-deny-users-file=/etc/ftpusers
u-deny-users-file=/usr/local/etc/ftpusers
#u-deny-users-file=  (commented out)

u-deny-users-file=/etc/ftpusers