The /etc/ftphosts file is used to define whether users are allowed to log in from certain hosts or whether there are denied access.
Create the ftphosts file, touch /etc/ftphosts and add for example in this file the following lines:
| 
          # Example host access file
          #
          # Everything after a '#' is treated as comment,
          # empty lines are ignored
          allow ftpadmin 208.164.186.1 208.164.186.2 208.164.186.4
          deny ftpadmin 208.164.186.5
         | 
Now, change its default permission to be 600:
| 
          [root@deep ] /# chmod 600 /etc/ftphosts
         | 
The /etc/ftpusers/ file specifies those users that are NOT allowed to connect to your FTP server.
Create the ftpusers file, touch /etc/ftpusers and add in this file the following users for security reasons:
| 
            root
            bin
            daemon
            adm
            lp
            sync
            shutdown
            halt
            mail
            news
            uucp
            operator
            games
            nobody
           | 
Now, change its default permission to be 600:
| 
            [root@deep ] /# chmod 600 /etc/ftpusers
           |