docker-proxy using port when no containers are running

On a ubunty 1404 machine, docker-proxy is using port 6379, however there are no docker containers running. $ sudo netstat -tulpn | grep docker tcp6 0 0 :::6379 :::* LISTEN 28438/docker-proxy tcp6 0 0 :::2376 :::* LISTEN 28266/dockerd $ docker ps -all CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES $ After I stop docker service, this process is gone, and that port is available, however when I start docker back up, docker-proxy is still using that port even though there are no docker containers running. $ docker info ## Output: Containers: 0 Running: 0 Paused: 0 Stopped: 0 Images: 0 Server Version: 1.12.0 Storage Driver: aufs Root Dir: /var/lib/docker/aufs Backing Filesystem: extfs Dirs: 0 Dirperm1 Supported: true Logging Driver: json-file Cgroup Driver: cgroupfs Plugins: Volume: local Network: bridge null host overlay Swarm: inactive Runtimes: runc Default Runtime: runc Security Options: apparmor Kernel Version: 4.2.0-38-generic Operating System: Ubuntu 14.04.4 LTS OSType: linux Architecture: x86_64 CPUs: 16 Total Memory: 31.32 GiB Name: xxxxx ID: LILE:5WFT:2EPL:OXCN:GZG7:C4WE:AFCX:LNAT:TBMG:XQFP:QX7W:XLYK Docker Root Dir: /var/lib/docker Debug Mode (client): false Debug Mode (server): false Registry: https://index.docker.io/v1/ WARNING: No swap limit support Insecure Registries: 127.0.0.0/8