1.输入该命令按回车键

vi /etc/systemd/resolved.conf

2.按i进入插入模式，修改为例如

DNS=8.8.8.8 223.5.5.5

然后按ESC键输入wq按回车键保存退出vi编辑

3.输入该命令按回车键

systemctl restart systemd-resolved

4.输入该命令按回车键

systemctl enable systemd-resolved

5.输入该命令按回车键

mv /etc/resolv.conf /etc/resolv.conf.bak

6.输入该命令按回车键

ln -s /run/systemd/resolve/resolv.conf /etc/resolv.conf

7.输入该命令按回车键查看设置情况，重启服务验证

cat /etc/resolv.conf