1. 上网上不了

配置网卡ifcfg-ens33

2.yum仓库问题

[root@localhost yum.repos.d]# yum update yum
已加载插件：fastestmirror
http://mirrors.aliyun.com/centos/7/os/x86_64/repodata/repomd.xml: [Errno 14] curl#7 - "Failed to connect to : 网络不可达"
Could not retrieve mirrorlist http://mirrorlist.centos.org/?release=7&arch=x86_64&repo=extras&infra=stock error was
14: curl#6 - "Could not resolve host: mirrorlist.centos.org; 未知的错误"
Cannot find a valid baseurl for repo: extras/7/x86_64

更新CentOS-Base.repo  yum源为阿里云的：

mirrors.aliyun.com

3.  

root@localhost yum.repos.d]# wget
-bash: wget: 未找到命令

安装wget

yum install wget