1. List all services enabled/disabled on boot (ex chkconfig –list)

[code]systemctl list-unit-files[/code]

2. Enable HTTPD + Mysql service on system boot:

[code]
systemctl enable httpd
systemctl enable mariadb
[/code]

3. Reverting to iptables from firewalld

[code]
systemctl stop firewalld
systemctl mask firewalld

yum install iptables-services

systemctl enable iptables
systemctl start iptables

# to save iptables rules use
service iptables save

[/code]