# 切换到yum目录
[root@localhost ~]# cd /etc/yum.repos.d/
# 创建备份目录
[root@localhost yum.repos.d]# mkdir repo.bak
[root@localhost yum.repos.d]# ls
CentOS-Base.repo       CentOS-fasttrack.repo  CentOS-Vault.repo
CentOS-CR.repo         CentOS-Media.repo  ....
# 把原来的yum文件移到到备份目录
[root@localhost yum.repos.d]# mv *.repo repo.bak/
# 下载阿里的yum源
[root@localhost yum.repos.d]# curl -o /etc/yum.repos.d/CentOS-Base.repo  http://mirrors.aliyun.com/repo/Centos-7.repo
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100  2523  100  2523    0     0  20847      0 --:--:-- --:--:-- --:--:-- 21025
# 清理yum
[root@localhost yum.repos.d]# yum clean all && yum makecache

# 安装net-tools包
[root@localhost ~]# yum install -y net-tools

# 测试
[root@localhost ~]# ifconfig

[root@localhost /]# hostnamectl set-hostname controller
[root@localhost /]# bash
[root@controller /]# 
[root@controller /]# vim /etc/hosts
192.168.10.10 controller

#测试
[root@controller /]# ping controller
PING controller (192.168.10.10) 56(84) bytes of data.
64 bytes from controller (192.168.10.10): icmp_seq=1 ttl=64 time=0.039 ms
64 bytes from controller (192.168.10.10): icmp_seq=2 ttl=64 time=0.062 ms
^C
--- controller ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 999ms
rtt min/avg/max/mdev = 0.039/0.050/0.062/0.013 ms
[root@controller /]# 

[root@controller /]# systemctl stop firewalld
[root@controller /]# systemctl enable firewalld
Created symlink from /etc/systemd/system/dbus-org.fedoraproject.FirewallD1.service to /usr/lib/systemd/system/firewalld.service.
Created symlink from /etc/systemd/system/multi-user.target.wants/firewalld.service to /usr/lib/systemd/system/firewalld.service.
[root@controller /]# systemctl status firewalld.service 
● firewalld.service - firewalld - dynamic firewall daemon
   Loaded: loaded (/usr/lib/systemd/system/firewalld.service; enabled; vendor preset: enabled)
   Active: inactive (dead)
     Docs: man:firewalld(1)
[root@controller /]#