vi /etc/sysconfig/network-scripts/ifcfg-
将ONBOOT 改为yes
重启网络服务：
service network restart / systemctl restart network
安装net-tools
yum install net-tools
启动sshd服务
service sshd start
更(换)新源
yum -y install wget
mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo_bak
wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo
yum makecache
yum -y update