# Tunneled RDP Connections

Remote Desktop Protocol (**RDP**) is a standard for using a desktop computer remotely. It was released by Microsoft and is most commonly used to access Windows systems, but can be used for macOS and Linux systems as well.

This example assumes you've already [created a TCP route](https://www.pomerium.com/docs/capabilities/non-http/tcp.md#configure-tcp-routes) for this service.

## Basic Connection

1. Create a TCP tunnel, using either [`pomerium-cli`](https://www.pomerium.com/docs/deploy/clients.md) or the Pomerium Desktop client:

**pomerium-cli:**

```bash
pomerium-cli tcp aService.corp.example.com:3389 --listen :3389
```

The `--listen` flag is optional. It lets you define what port the tunnel listens on locally. If not specified, the client will choose a random available port.

**Pomerium Desktop:**

\[An example connection to a RDP service from Pomerium Desktop]

The **Local Address** field is optional. Using it defines what port the tunnel listens on locally. If not specified, Pomerium Desktop will choose a random available port.

1. Initiate your RDP connection, pointing to `localhost`. This example uses the [Remmina](https://remmina.org/) client, but the procedure should be similar for other tools:

   \[A new connection profile in Remmina]

   The first connection attempt will initiate a redirect to authenticate you in the browser. Once you're signed in, subsequent connections will succeed. If your client isn't configured to retry the connection, you may have to reconnect manually.

## Always Tunnel through Pomerium

Some clients, like Remmina, support running commands before and after connection. The script below (adopted from [this example](https://kgibran.wordpress.com/2019/03/13/remmina-rdp-ssh-tunnel-with-pre-and-post-scripts/) using SSH tunnels) starts and stops an instance of `pomerium-cli`:

1. Save the script above to your home folder (`~/`), and make it executable:

   ```bash
   cd ~/
   wget https://github.com/pomerium/pomerium/blob/main/examples/tcp/pomerium-tunnel.sh
   chmod +x pomerium-tunnel.sh
   ```

2. Update your client profile to execute the script before and after the connection:

   \[A connection profile in Remmina invoking a custom script]

Flatpak versions of client software may not be able to read external scripts or programs.

## More Resources

- [Remote Desktop Protocol (Wikipedia)](https://en.wikipedia.org/wiki/Remote_Desktop_Protocol)
- [Remmina (Linux)](https://remmina.org/)
- [Microsoft Remote Desktop (macOS)](https://apps.apple.com/us/app/microsoft-remote-desktop/id1295203466?mt=12)