Linux firewall turned off

service iptables status can view the current status of the iptables service.
But even if the service is running, the firewall may not work, you have to look at the firewall rules settings iptables -L
Here are some commands for starting and closing the firewall:
        1) Take effect after reboot
        On: chkconfig iptables on
        Off: chkconfig iptables off
        2) Immediately effective, invalid after restart
        Start: service iptables start
        Shutdown: service iptables stop