> ## Documentation Index
> Fetch the complete documentation index at: https://docs.gcore.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Add CDN servers to the origin ACL whitelist

If you have restrictions on your origin, there are three ways to whitelist the CDN servers:

* via HTTP headers (recommended)
* via CDN servers' IP addresses
* via CDN servers' subnets

<Info>
  **Info**
  We continually expand our network, so **the list of servers changes constantly**. If you fail to add the IP address of a new server or a subnet to the whitelist, users cannot access content from that edge server. We recommend writing a script that automatically updates your ACL. New IP addresses or subnets are added to our list 30-60 minutes before launching a new server.
</Info>

## Whitelist via HTTP headers

Use the [Add Request Headers](/cdn/cdn-resource-options/http-headers/specify-http-headers-that-cdn-adds-to-requests-to-the-origin) option to set up a custom header.

We recommend this method as it does not require further updates once set up. In contrast, the list of IP addresses must be regularly updated.

## Whitelist via IP addresses

You can fetch the IP addresses of the CDN servers by using this API request:

```sh theme={null}
curl -i -X GET https://api.gcore.com/cdn/public-ip-list
```

## Whitelist via subnets

You can fetch the IP addresses of the CDN subnets using this API request:

```sh theme={null}
curl -i -X GET https://api.gcore.com/cdn/public-net-list 
```