網頁設計
2. Start and enable the iptables service to be enabled at boot automatically.
 

2. Post running the above commands you would get an empty iptable rules as shown below.

Created symlink from /etc/systemd/system/firewalld.service to /dev/null.

安裝iptables
Install and configure iptables
1. To enable iptables, first we have to install the “iptables-services” package.
 

住手及封閉firewalld
1. To begin with, you should disable Firewalld and make sure it does not start at boot again.
 

2. Masking the firewalld service creates a symlink from /etc/systemd/system/firewalld.service to /dev/null thus disabling the firewalld service.

 

參考文章
https://www.thegeekdiary.com/how ... s-in-centos-rhel-7/

Check to see if any rules are left behind from firewalld. By default a fresh intall of iptables would have iptables rules as shown below.
 

斷根規則
Clearing leftover firewalld rules
1. If needed you can clear iptables rules left over from firewalld with the following commands.