1. Tạo rules cho iptables đối với Oracle trên centos7: 
     # service iptables start
 # chkconfig iptables on
 # iptables -A INPUT -p tcp --dport 22 -j ACCEPT
 # iptables -A INPUT -p tcp --dport 1521 -j ACCEPT
 # service iptables save
 # service iptables status
  2. Tạo rules cho firewallD đối với Oracle trên centos7: 
     # systemctl start firewalld.service
 # systemctl enable firewalld.service
 # firewall-cmd --permanent --zone=public --add-port=22/tcp
 # firewall-cmd --permanent --zone=public --add-port=1521/tcp
 # firewall-cmd --reload
 # firewall-cmd --permanent --zone=public --list-ports
 1521/tcp 22/tcp
  3. Các rules cho firewallD khác: 
     # firewall-cmd --permanent --zone=public --remove-port=8080-8081/tcp
 # firewall-cmd --permanent --zone=public --add-rich-rule="rule family="ipv4" source address="192.168.0.4/24" service name="http" accept"
 # firewall-cmd --permanent --zone=public --remove-rich-rule="rule family="ipv4" source address="192.168.0.4/24" service name="http" accept"

Thank you for your reading. Done!