Subscriber Provided Prefix

Fastly's Subscriber Provided Prefix product allows you to bring your own IP addresses and have them announced, routed, and served by Fastly infrastructure for use with production services. When you purchase this product, you provide your own IP addresses to Fastly rather than use Fastly IP addresses. You can then direct traffic to your own IP addresses, which are reachable via HTTP Anycast on Fastly's infrastructure.

We recommend this service for customers who want to control their addresses by separating their network layer concerns from their content delivery concerns. By combining Fastly's Subscriber Provided Prefix service with our Origin Connect product and our DDoS Protection and Mitigation service, you can protect your origin servers by directing traffic through Fastly's global network.

For more details about this product, including how to purchase it, contact your account manager or email


To purchase Fastly's Subscriber Provided Prefix service you must also purchase Fastly's Enterprise Support package and our IP-to-Service Pinning Setup service.

When you sign up for this product, you'll need to provide Fastly with an executed Letter of Authorization (LOA), on a form we provide, that grants us permission to announce your prefixes. The LOA includes, at a minimum, the IP blocks to announce, the registry and object identifier, as well as the administrative, technical, and abuse contacts for those prefixes.

Using the Subscriber Provided Prefix product requires at least one /24 IPv4 or /48 IPv6 prefix for announcement purposes. Additional prefixes and larger prefixes are also supported. These prefixes must not be originated from any autonomous system number (ASN) at the time Fastly announces them. They should also be dormant for a period of approximately three months prior to use by Fastly.

How the Subscriber Provided Prefix product works

Fastly will announce the designated prefixes identified in your LOA. Your prefixes will be announced along with existing Fastly prefixes and will be originated from the Fastly Autonomous System (AS) Number AS54113. The Subscriber Provided Prefix product supports HTTP and HTTPS traffic only and your prefixes will be terminated at Fastly for these two protocols. We make routing announcements on a global basis unless you request they be constrained to our defined North America and Europe region.

To enable specific IP addresses within your announced prefix, Fastly combines this Subscriber Provided Prefix product with our IP-to-Service Pinning feature, which must be purchased separately. IP addresses that are not service pinned will not serve your traffic.

After completing all the necessary routing announcements and setup within your CDN services, Fastly needs additional time to complete the setup. In general, you should allow for at least 45 days of lead time for us to set up routing announcements and CDN service. Your service order identifies the specific lead time Fastly needs for full operability.

You may provide Fastly notice at any time to withdraw your prefix announcement by opening a ticket at We need at least 45 days of notice to permanently remove routing announcements and CDN service for your designated prefixes. When we receive notice of your request for prefix withdrawal, we will provide you with a withdrawal process timeline. This process starts with us reconfiguring your service within the Fastly network. When that reconfiguration work completes, you must then point your DNS records at Fastly to ensure uninterrupted service. Once your traffic is moved from your prefix to a Fastly prefix, we will withdraw the announcement.

Working with the Subscriber Provided Prefix API

After the initial setup is completed, you can use the Subscriber Provided Prefix API to programmatically access the Subscriber Provided Prefix service. You can use the Subscriber Provided Prefix API for tasks like automating the creation and maintenance of your IP addresses or customizing the attributes on IP addresses, such as supported protocols and TLS versions. For more information, contact

Conditions and limitations

When using Fastly's Subscriber Provided Prefix product you agree to the following limitations:

  • Your purchase of the Subscriber Provided Prefix product entitles you to the announcement of the specified IP prefixes identified in your LOA. Any additional prefixes beyond your initial order will require an additional purchase of this product.
  • Fastly does not provide termination or proxy services for non-HTTP and non-HTTPS protocols with this product.
  • Fastly does not provide general network transit or peering services as part of this product.

When using Fastly's Subscriber Provided Prefix product you agree to the following conditions:

  • Your IP addresses are your assets. They belong to you and are not a Fastly service. Fastly has no liability for your assets.
  • You will pay additional fees if you withdraw your prefixes for the purpose of replacing or updating them.
  • Your provided prefixes will not have any negative IP reputation associated with them as determined by us. Fastly will scan your prefixes against common IP reputation databases prior to announcement to ensure your IP reputation remains neutral or positive.
  • You must maintain transit connectivity to Fastly for origin traffic. Prefixes provided to Fastly for this service must not overlap with IP addressing used by your origin servers.
  • Fastly retains exclusive announcement rights for your prefixes. Conflicting announcements will disrupt or prevent traffic delivery.

To specifically mitigate DDoS attacks, you agree that:

  • Prefix announcements Fastly makes for you may include regional capacity announcements.
  • Fastly may prepend, remove, or blackhole routing announcements in the event of a DDoS attack.
  • Fastly may de-aggregate your prefixes at our discretion to improve network reliability.
  • Fastly may perform these actions even if you have not purchased the Fastly DDoS protection and mitigation service.

For any IP addresses not pinned to a service but contained within your Subscriber Provided Prefix product, Fastly's Varnish servers will return a TCP reset or an HTTP 500 error response code.


Fees for Subscriber Provided Prefix include a set up charge and a monthly rate for two anycast prefixes configurations, one IPv4 and one IPv6 IP range. Additional prefixes and larger prefixes can be included for a higher fee. Announcements can be made either globally or for North America and the EU.

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