Installing FirewallD on CentOS 8

• Installing FirewallD
• Enable FirewallD
• Opening Ports and Services

Installing FirewallD

firewalld is installed by default on some Linux distributions, including many images of CentOS 8. However, it may be necessary for you to install firewalld yourself:

yum install firewalld

Enable FirewallD

After you install firewalld, you can enable it as a system service:

systemctl enable firewalld
systemctl start firewalld
firewall-cmd --state

Opening Ports and Services

Enable available services:

firewall-cmd --permanent --zone=public --add-service=cockpit --add-service=http  --add-service=https
firewall-cmd --reload
firewall-cmd --zone=public --list-services

And open specific ports:

firewall-cmd --permanent --zone=public --add-port=12345/tcp
firewall-cmd --reload
firewall-cmd --zone=public --list-ports

For Docker

firewall-cmd --zone=public --change-interface=docker0 --permanent
firewall-cmd --zone=public --add-masquerade --permanent
firewall-cmd --reload
firewall-cmd --list-all