My servers work under Ubuntu 16.04.3 LTS (4.13.0-36-generic) I used docker.io and had my containers lose network. I switched to docker-ce and things got better. But anyway one of my servers continue experiencing this (or similar) issue. Containers are alive but have no network. I tried to restart containers and ~ a minute after restart issue appears again. The only docker daemon restart helps. But anyway after a couple of weeks I had it appears again.