Could not retrieve mirrorlist http://mirrorlist.centos.org/?release=7&arch=x86_64&repo=os&infra=stoc

Centos7使用yum安装程序是遇到这样的问题：

Could not retrieve mirrorlist http://mirrorlist.centos.org/?release=7&arch=x86_64&repo=os&infra=stock error was
14: curl#7 - "Failed to connect to 2604:1580:fe02:2::10: Network is unreachable"
 

解决方法：      

 1.   sudo vi /etc/sysconfig/network-scripts/ifcfg-ens33 

　　2.   将ONBOOT改为yes，wq!保存退出

       3.    重新启动网络

             service network restart