举个例子,ping hub.docker.com不通
提示ping: hub.docker.com: Temporary failure in name resolution
查看/etc/resolv.conf
sudo vim /etc/resolv.conf
发现只有本机的172.x.x.x
进入输入模式,多加几个DNS
nameserver 8.8.8.8
nameserver 8.8.4.4
nameserver 114.114.114.114
保存退出
重启DNS resolver service
sudo systemctl restart systemd-resolved.service
再ping就通了