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
        
        In the example below, we allow the user ftpadmin to connect via FTP from the explicitly listed addresses 208.164.186.1 208.164.186.2 208.164.186.4, and 
        deny the specified ftpadmin user to connect from the site 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