https://blog.csdn.net/cc_want/article/details/85337241
CentOS7.x own firewall firewall, FTP turn requires using several ports 202,122 30000-35000.
Use the following command:
firewall-cmd = --zone = Port 20 is public---add / TCP --permanent
firewall-cmd - public --add-Port = -zone = 21 is / TCP --permanent
Firewall-cmd = --zone = Port 22 is public---add / TCP --permanent
Firewall-cmd = --zone public --add-Port = 30000-35000 / TCP --permanent
Firewall-cmd = --zone = Port 20 is public---add / UDP --permanent
Firewall-cmd = --zone = Port 21 is public---add / UDP --permanent
Firewall- cmd --zone = public --add-port = 30000-35000 / udp --permanent
after successfully added, restart the firewall, you can!
systemctl restart firewalld.service