# Port forwarding to run web services

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Q Blocks instances offer support for running web services with public access. This is enabled through port forwarding.

A web service can be forwarded at an open port of the Q Blocks instance and then accessed publicly.

> 🔐 Due to security reasons, all ports are not open. Only some random ports can be opened.

The pre-configured open ports of your instance can be viewed as follows:

1. Go to your [Active Instances](https://www.qblocks.cloud/client/v2/instances) Page.
2. Click on the dropdown icon on your instance row to view instance info.
3. **Extra Ports** section displays the open port as seen below:

<figure><img src="/files/wXvOl8FT1QpxZGThxLO5" alt=""><figcaption></figcaption></figure>

> 🗒️ Copy the **Extra port** and **Host** values

### Example of a web service:

As an example, let us run **Tensorboard** web service in our instance. Tensorboard is a Machine learning experiment tracking software that can be launched as a web service and then accessed in your browser.

Run the following commands in your instance’s terminal:

```bash
pip install tensorboard
tensorboard --logdir LOG_FOLDER --host=0.0.0.0 --port EXTRA_PORT
```

> Replace <mark style="color:red;">EXTRA\_PORT</mark> with the Port number copied above.

This should launch the service and it should be accessible at the following URL:

```html
http://HOST:EXTRA_PORT
```

The same way, you can launch any web service in your instance at a provided port.

**Please see:**

> *Any application running at a forwarded port is accessible to the public. Right precautions with auth token or password access must be implemented to secure the applications.*

If you still face issues setting it up then don't hesitate to reach out to us at: [support@qblocks.cloud](mailto:support@qblocks.cloud?subject=Unable%20to%20launch%20TensorBoard)


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