dns安装配置
yum -y install dnsmasq
dns配置文件
vi /etc/dnsmasq.conf
resolv-file=/etc/resolv.dnsmasq.conf
addn-hosts=/etc/dnsmasq.hosts
指定向上一级访问的dns
vi /etc/resolv.dnsmasq.conf
meserver 114.114.114.114
nameserver 8.8.4.4
vi /etc/dnsmasq.hosts 解析域名（里面添加需要解析的域名）
192.168.1.16 aa.132.bb
192.168.1.16 dd.123.cc
客户端使用方法:
echo "nameserver 10.0.0.101" > /etc/resolv.conf