RHEL 7中防火墙的配置和使用方法

RHEL7 中使用了firewalld代替了原来的iptables，操作设置和原来有点不同：

查看防火墙状态：systemctl status firewalld

启动防火墙：systemctl start firewalld

停止防火墙：systemctl stop firewalld

防火墙中的一切都与一个或者多个区域相关联，下面对各个区进行说明：

Zone         Description -----------------------------------------------------drop (immutable)     Deny all incoming connections, outgoing ones are accepted. block (immutable)    Deny all incoming connections, with ICMP host prohibited messages issued. trusted (immutable)    Allow all network connections public       		Public areas, do not trust other computersexternal       		For computers with masquerading enabled, protecting a local network dmz        		For computers publicly accessible with restricted access. work        		For trusted work areas home        		For trusted home network connections internal       		For internal network, restrict incoming connections