CentOS6
永久性生效，重启后不会复原
开启：chkconfig iptables on
关闭：chkconfig iptables off
即时生效，重启后复原
开启：service iptables start
关闭：service iptables stop
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CentOS7
查看防火墙状态
firewall-cmd --state
停止firewall
systemctl stop firewalld
禁止firewall开机启动
systemctl disable firewalld
