Ping error: unknown name or service

1、 error

background ：centos7
operation ： Install plug-ins online in the operating system , Find that all kinds of connections are not connected to the Internet , And the use of ：ping www.baidu.com Wrong orders , The error screenshot is shown below ：

2、 solve

cd /etc/sysconfig/network-scripts
#  Edit network card profile 
vi ifcfg-ens33
#  Add content at the bottom of the content ：DNS1=8.8.8.8
#  Restart network service 
systemctl restart network.service

3、 verification