update firewall rules on RHEL7

1. problem

How to update firewall rules on RHEL7?

2. solution

1> list rules

sudo firewall-cmd --zone=public --list-ports

2> add port rule

sudo firewall-cmd --zone=public --add-port=your-port/tcp[or udp] --permanent

Comments:
—zone=public is like a mark to set or query options. (I guess so???)
—permanent means the rule is useful permanently event if the OS is restarted.

3> remove port rule

sudo firewall-cmd --zone=public --remove-port=your-port/tcp[or udp] --permanent

4> query port rule

sudo firewall-cmd --zone=public --query-port=your-port/tcp[or udp]

5> reload firewall rule

sudo firewall-cmd --reload

3. reference

[1] https://hui8080.iteye.com/blog/2362188
[2] firewall-cmd –help