Explore networking features on Docker Desktop
Docker Desktop provides several networking features to make it easier to use.
Docker Desktop networking can work when attached to a VPN. To do this, Docker Desktop intercepts traffic from the containers and injects it into the host as if it originated from the Docker application.
When you run a container with the
-p argument, for example:
$ docker run -p 80:80 -d nginx
Docker Desktop makes whatever is running on port 80 in the container, in
nginx, available on port 80 of
localhost. In this example, the
host and container ports are the same. If, for example, you already have something running on port 80 of
your host machine, you can connect the container to a different port:
$ docker run -p 8000:80 -d nginx
Now, connections to
localhost:8000 are sent to port 80 in the container. The
Docker Desktop on Mac and Linux allows you to use the host’s SSH agent inside a container. To do this:
Bind mount the SSH agent socket by adding the following parameter to your
SSH_AUTH_SOCKenvironment variable in your container:
$ -e SSH_AUTH_SOCK="/run/host-services/ssh-auth.sock"
To enable the SSH agent in Docker Compose, add the following flags to your service:
services: web: image: nginx:alpine volumes: - type: bind source: /run/host-services/ssh-auth.sock target: /run/host-services/ssh-auth.sock environment: - SSH_AUTH_SOCK=/run/host-services/ssh-auth.sock
The internal IP addresses used by Docker can be changed from Settings. After changing IPs, it is necessary to reset the Kubernetes cluster and to leave any active Swarm.
Because of the way networking is implemented in Docker Desktop, you cannot
docker0 interface on the host. This interface is actually within the
Docker Desktop can't route traffic to Linux containers. However if you're a Windows user, you can ping the Windows containers.
The docker bridge network is not reachable from the host. However if you are a Windows user, it works with Windows containers.
The host has a changing IP address, or none if you have no network access.
We recommend that you connect to the special DNS name
which resolves to the internal IP address used by the host.
You can also reach the gateway using
If you have installed Python on your machine, use the following instructions as an example to connect from a container to a service on the host:
Run the following command to start a simple HTTP server on port 8000.
python -m http.server 8000
If you have installed Python 2.x, run
python -m SimpleHTTPServer 8000.
Now, run a container, install
curl, and try to connect to the host using the following commands:
$ docker run --rm -it alpine sh # apk add curl # curl http://host.docker.internal:8000 # exit
Port forwarding works for
-P all work.
Ports exposed from Linux are forwarded to the host.
We recommend you publish a port, or to connect from another container. This is what you need to do even on Linux if the container is on an overlay network, not a bridge network, as these are not routed.
For example, to run an
$ docker run -d -p 80:80 --name webserver nginx
To clarify the syntax, the following two commands both publish container's port
80 to host's port
$ docker run --publish 8000:80 --name webserver nginx $ docker run -p 8000:80 --name webserver nginx
To publish all ports, use the
-P flag. For example, the following command
starts a container (in detached mode) and the
-P flag publishes all exposed ports of the
container to random ports on the host.
$ docker run -d -P --name webserver nginx
run command for more details on
publish options used with