1.关闭subscription-manager

vi /etc/yum/pluginconf.d/subscription-manager.conf

enable = 0

2.通过浏览器下载Centis-7.repo

http://mirrors.aliyun.com/repo/Centos-7.repo

3.上传至/etc/yum.repos.d/

4.修改Centos-7.repo文件

#cd /etc/yum.repos.d/
#ls
#vim CentOS-Base.repo
执行:%s/$releasever/7/g快速替换

#yum clean all
#yum update

5.安装epel源

#rpm -Uvh https://dl.fedoraproject.org/pub/epel/epel-release-latest-7.noarch.rpm

6.安装iftop软件

# yum install iftop -y

【End】