# IP Whitelisting

Whitelist our IP address so that Stacksync can connect to your app. IP whitelisting is optional and is only necessary if your services sit behind a firewall filtering for IP addresses.

{% hint style="info" %}
The IPs you can whitelist are displayed to you during thee App/Database authentication process.
{% endhint %}

<figure><img src="https://2867423571-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FfJjIdV9cuW6K8asJjTPJ%2Fuploads%2F7k9BCKfVgeITRbxHOrPe%2F1%20(1).png?alt=media&#x26;token=a1bf5047-9df0-41be-89ff-3e663834ee93" alt=""><figcaption><p>View the IP addresses to whitelist for specific regions.</p></figcaption></figure>

There is one IP address to whitelist for every region.

<table><thead><tr><th width="249">Region</th><th>IP address to whitelist</th></tr></thead><tbody><tr><td>🇧🇪 Belgium (St. Ghislain)</td><td><em>IP available during the authentication process</em></td></tr><tr><td>🇺🇸 US Central (Iowa)</td><td><em>IP available during the authentication process</em></td></tr><tr><td>Other regions</td><td>request at <a href="mailto:hello@stacksync.com"><mark style="color:purple;">hello@stacksync.com</mark></a></td></tr></tbody></table>

{% hint style="info" %}
Make sure to whitelist the IP address **BEFORE** connecting your app.

During the app setup, Stacksync will connect to your app to retrieve its schema. Therefore, Stacksync's IP address needs to be whitelisted before that time.
{% endhint %}

Ensure that the resources you are whitelisting Stacksync IPs for are in a **public subnet**. Whitelisting public IPs for a resource in a **private subnet** will not allow Stacksync to access the resource from the public internet.

If you are attempting to provide direct access to a **database** in a private subnet, we recommend setting up a **jumpbox** as outlined in our documentation to connect using SSH tunneling:

{% content-ref url="ssh-tunneling" %}
[ssh-tunneling](https://docs.stacksync.com/two-way-sync/connectors/setup-options/ssh-tunneling)
{% endcontent-ref %}

Alternatively, if creating a jumpbox is not feasible, Stacksync can establish a **private connection** to your subnet using **VPN tunneling** or **AWS Transit Gateway** or **Private Link**. Email us at <hello@stacksync.com> if you need to connect using a private connection, i.e. without crossing the public internet.