# port Usage: docker port CONTAINER [PRIVATE_PORT[/PROTO]] List port mappings for the CONTAINER, or lookup the public-facing port that is NAT-ed to the PRIVATE_PORT You can find out all the ports mapped by not specifying a `PRIVATE_PORT`, or just a specific mapping: $ docker ps test CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES b650456536c7 busybox:latest top 54 minutes ago Up 54 minutes 0.0.0.0:1234->9876/tcp, 0.0.0.0:4321->7890/tcp test $ docker port test 7890/tcp -> 0.0.0.0:4321 9876/tcp -> 0.0.0.0:1234 $ docker port test 7890/tcp 0.0.0.0:4321 $ docker port test 7890/udp 2014/06/24 11:53:36 Error: No public port '7890/udp' published for test $ docker port test 7890 0.0.0.0:4321