Disabling firewalld
You can’t really run the old iptables utilities alongside firewalld. They’re just not compatible. The best way to get around this is to disable firewalld entirely (no need to uninstall it unless you want to) , and reinstall the iptables utilities. Disabling firewalld can be done using these commands:
Stop firewalld:
systemctl stop firewalld
Disable firewalld so it won’t start on boot:
