Fastly IP ranges & what they mean for fraud

Fastly publishes its CDN edge ranges. Like Cloudflare, requests originating from these ranges — rather than being served through them — are the signal of interest.

How Maskbreak uses these ranges

Because Fastly is a CDN, the useful distinction is traffic originating from these ranges versus traffic merely served through them — Maskbreak's signal applies to the former. The numbers above come from Fastly's own published range feed — the same feed Maskbreak's verdict pipeline refreshes daily, so a new range is scored within a day of publication, not whenever a static database ships.

Range data adds a signal; it never overrides deeper network detection. VPN exits live in datacenters, so a range hit doesn't short-circuit tunnel analysis — an IP in Fastly's ranges that is also a VPN exit gets both signals, and your policy sees the full picture in the reasons array.

What these ranges actually cover

Fastly publishes the public IP list for its edge network, covering the CDN points of presence that serve its customers' traffic.

Like Cloudflare, Fastly is a CDN rather than rented compute, so its addresses front legitimate consumer traffic for the sites that use it. A Fastly address arriving at your origin is far more likely to be a delivery path than an attacker. The datacenter signal is technically accurate and operationally close to useless on a consumer surface here.

Where this provider shows up in abuse

Fastly also powers image and API proxying for many mobile apps, so its ranges carry high volumes of ordinary app traffic.

None of this makes a range match a verdict. In Maskbreak's pipeline a datacenter hit contributes 40 points toward a 0–100 risk score — enough to reach review, never enough to block on its own — and it never short-circuits tunnel detection, because VPN and proxy exits are themselves hosted in datacenters. Which AS announces a given address is a separate question, answered in the ASN directory.

Should you block Fastly traffic?

Compute@Edge and similar products mean code, not people, initiates connections from these ranges.

The honest answer is: it depends on the surface. A datacenter IP on a signup, login, or checkout is a strong review signal — humans overwhelmingly arrive from residential and mobile networks. The same IP calling your API is often just a legitimate backend. Maskbreak returns the raw signal so you can apply exactly that asymmetric policy instead of a blanket block.

curl -X POST https://maskbreak.com/v1/evaluate \
  -H "Authorization: Bearer sk_test_sandbox" \
  -H "Content-Type: application/json" \
  -d '{"token":"test_datacenter"}'

The sandbox key returns the documented datacenter-verdict shape (decision, risk_score, network.datacenter) — no signup required. Details in the API docs.