--- description: Networking keywords: windows, networking title: Networking features in Docker Desktop for Windows --- {% assign Arch = 'Windows' %} Docker Desktop provides several networking features to make it easier to use. ## Features ### VPN Passthrough Docker Desktop networking can work when attached to a VPN. To do this, Docker Desktop intercepts traffic from the containers and injects it into {{Arch}} as if it originated from the Docker application. ### Port Mapping 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 this case, `nginx`) available on port 80 of `localhost`. In this example, the host and container ports are the same. What if you need to specify a different host port? 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 syntax for `-p` is `HOST_PORT:CLIENT_PORT`. ### HTTP/HTTPS Proxy Support See [Proxies](index.md#proxies). ## Known limitations, use cases, and workarounds Following is a summary of current limitations on the Docker Desktop for {{Arch}} networking stack, along with some ideas for workarounds. ### There is no docker0 bridge on {{Arch}} Because of the way networking is implemented in Docker Desktop for {{Arch}}, you cannot see a `docker0` interface on the host. This interface is actually within the virtual machine. ### I cannot ping my containers Docker Desktop for Windows can't route traffic to Linux containers. However, you can ping the Windows containers. ### Per-container IP addressing is not possible The docker (Linux) bridge network is not reachable from the Windows host. However, it works with Windows containers. ### Use cases and workarounds There are two scenarios that the above limitations affect: #### I want to connect from a container to a service on the host 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 `host.docker.internal` which resolves to the internal IP address used by the host. This is for development purpose and will not work in a production environment outside of Docker Desktop for Windows. You can also reach the gateway using `gateway.docker.internal`. 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: 1. 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`. 2. Now, run a container, install `curl`, and try to connect to the host using the following commands: ```console $ docker run --rm -it alpine sh # apk add curl # curl http://host.docker.internal:8000 # exit ``` #### I want to connect to a container from Windows Port forwarding works for `localhost`; `--publish`, `-p`, or `-P` all work. Ports exposed from Linux are forwarded to the host. Our current recommendation is to 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. The command to run the `nginx` webserver shown in [Getting Started](index.md#explore-the-application) is an example of this. ```bash $ 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 `8000`: ```bash $ 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. ```bash $ docker run -d -P --name webserver nginx ``` See the [run command](../engine/reference/commandline/run.md) for more details on publish options used with `docker run`.