centos open firewall port operations

1, view open ports in the firewall

sudo iptables -L -n

There are two ways to open ports

The first: Editing iptables file eg: sudo vi / etc / sysconfig / iptables

Add the need to open ports eg:

-A INPUT -m state –state NEW -m tcp -p tcp –dport 22 -j ACCEPT
-A INPUT -m state –state NEW -m tcp -p tcp –dport 80 -j ACCEPT
-A INPUT -m state –state NEW -m tcp -p tcp –dport 3306 -j ACCEPT
COMMIT

: Wq (save)

Then restart the firewall My approach is 

sudo systemctl stop firewalld.service-- turn off the firewall

sudo systemctl start firewalld.service-- open the firewall

The second method:

use 

firewall-cmd --permanent --add-port=80/tcp
或添加某一范围

firewall-cmd --permanent --add-port=1000-2000/tcp

Then restart the firewall My approach is 

sudo systemctl stop firewalld.service-- turn off the firewall

sudo systemctl start firewalld.service-- open the firewall