[root@dyw219 ~]# docker run --net=none -it centos /bin/bash
[root@01c6b82e8066 /]# ping -c2 172.17.42.1 connect: Network is unreachable
[root@01c6b82e8066 /]# exit exit
[root@dyw219 ~]# docker start 01c6b82e8066 01c6b82e8066
[root@dyw219 ~]# docker inspect 01c6b82e8066 | grep -i networkmode
"NetworkMode": "none",