In CentOS 7 or RHEL 7 or Fedora, firewalls are managed by firewalld

add to

Firewall CMD — zone = public — add port = 80/TCP — permanent (– permanent effective, invalid after restart without this parameter)

Firewall CMD — zone = public — add port = 1000-2000/TCP — permanent
reload

Firewall CMD — reload
View

Firewall CMD — zone = public — Query port = 80/TCP
delete

Firewall CMD — zone = public — remove port = 80/TCP — permanent
turn on the firewall

Systemctl start firewalld. Service
turn off the firewall

Systemctl stop firewalld. Service
View running status

Firewall CMD — state// running means running