## Enable remote access

You can enable remote access to the daemon either using a `docker.service` systemd unit file for Linux distributions using systemd.
Or you can use the `daemon.json` file, if your distribution doesn't use systemd.

Configuring Docker to listen for connections using both the systemd unit file
and the `daemon.json` file causes a conflict that prevents Docker from starting.

### Configuring remote access with systemd unit file

1. Use the command `sudo systemctl edit docker.service` to open an override file
   for `docker.service` in a text editor.

2. Add or modify the following lines, substituting your own values.

   ```systemd
   [Service]
   ExecStart=
   ExecStart=/usr/bin/dockerd -H fd:// -H tcp://127.0.0.1:2375
   ```

3. Save the file.

4. Reload the `systemctl` configuration.

   ```console
   $ sudo systemctl daemon-reload
   ```

5. Restart Docker.

   ```console
   $ sudo systemctl restart docker.service
   ```

6. Verify that the change has gone through.

   ```console
   $ sudo netstat -lntp | grep dockerd
   tcp        0      0 127.0.0.1:2375          0.0.0.0:*               LISTEN      3758/dockerd
   ```

### Configuring remote access with `daemon.json`

1. Set the `hosts` array in the `/etc/docker/daemon.json` to connect to the Unix
   socket and an IP address, as follows:

   ```json
   {
     "hosts": ["unix:///var/run/docker.sock", "tcp://127.0.0.1:2375"]
   }
   ```

2. Restart Docker.

3. Verify that the change has gone through.

   ```console
   $ sudo netstat -lntp | grep dockerd
   tcp        0      0 127.0.0.1:2375          0.0.0.0:*               LISTEN      3758/dockerd
   ```

### Allow access to the remote API through a firewall

If you run a firewall on the same host as you run Docker, and you want to access
the Docker Remote API from another remote host, you must configure your firewall
to allow incoming connections on the Docker port. The default port is `2376` if
you're using TLS encrypted transport, or `2375` otherwise.

Two common firewall daemons are:

- [Uncomplicated Firewall (ufw)](https://help.ubuntu.com/community/UFW), often
  used for Ubuntu systems.
- [firewalld](https://firewalld.org), often used for RPM-based systems.

Consult the documentation for your OS and firewall. The following information
might help you get started. The settings used in this instruction are
permissive, and you may want to use a different configuration that locks your
system down more.

- For ufw, set `DEFAULT_FORWARD_POLICY="ACCEPT"` in your configuration.

- For firewalld, add rules similar to the following to your policy. One for
  incoming requests, and one for outgoing requests.

  ```xml
  <direct>
    [ <rule ipv="ipv6" table="filter" chain="FORWARD_direct" priority="0"> -i zt0 -j ACCEPT </rule> ]
    [ <rule ipv="ipv6" table="filter" chain="FORWARD_direct" priority="0"> -o zt0 -j ACCEPT </rule> ]
  </direct>
  ```

  Make sure that the interface names and chain names are correct.

## Additional information

For more detailed information on configuration options for remote access to the daemon, refer to the
[dockerd CLI reference](/reference/cli/dockerd/#bind-docker-to-another-hostport-or-a-unix-socket).