For pureftp:
open /etc/pure-ftpd.conf, and this line
PassivePortRange 30000 35000
For proftp:
Open /etc/proftpd.conf, and add this line
PassivePorts 30000 35000
For vsftp:
open /etc/vsftpd/vsftpd.conf and add these lines
pasv_enable=YES
pasv_min_port=30000
pasv_max_port=35000
Restart FTP and make sure enable port range above to firewall. Restart firewall.
