Linux RHEL OS security

Systemd

systemctl list-units --type service --all
systemctl status [service]
systemctl enable [service]

Firewalld

firewall-cmd --list-all
firewall-cmd --get-services
cat /usr/lib/firewalld/services/[service].xml
firewall-cmd --permanent --add-service=[service]
firewall-cmd --add-port=[port]/[tcp or udp]
firewall-cmd --reload

SELinux

getsebool -a | grep [service]
setsebool -P [service]