ping www.baidu.com ping不通，报错
[root@localhost /]# ping www.baidu.com
ping: www.baidu.com: Name or service not known
按照这种方法，在/etc/resolv.conf文件首行加入namesever 8.8.8.8 保存并退出 就可以了
The DNS server seems out of order. You can use another DNS server such as 8.8.8.8. Put nameserver 8.8.8.8 to the first line of /etc/resolv.conf.