错误提示有：
Get https://registry-1.docker.io/v1/repositories/library/owncloud/tags/latest: dial tcp: lookup registry-1.docker.io on 10.242.197.247:53: read udp 10.242.197.247:53: i/o timeout
Network timed out while trying to connect to https://index.docker.io/v1/repositories/library/owncloud/images. You may want to check your internet connection or if you are behind a proxy.
试过vpn和ss，没有用，有谁教一下该怎么弄？用DaoCloud拉取官方的Docker Hub的镜像速度的确不错。命令也简单dao pull nginx:latest。
还有拉取Docker Hub上的镜像不是用docker pull nginx:latest这样的命令嘛？为啥用wget？
sudo route del -net 172.16.0.0 netmask 255.240.0.0
网络问题 推荐使用daocloud 提供的镜像加速