前提是本服务器能上网 Ping www.baidu.com
构建DNS缓存服务器
[root@localhost ~]# rpm -qa | grep -w bind //检查有没有bind。bind-libs和bind-utils
[root@localhost ~]# yum -y install bind //安装bind
[root@localhost ~]# vim /etc/named.conf //修改配置文件
[root@localhost ~]# systemctl restart named
[root@localhost ~]# setenforce 0 //关闭Linux安全机制
[root@localhost ~]# systemctl stop firewalld //关闭防火墙
[root@localhost ~]# iptables -F //关闭另一个防火墙