Cloudflare's Smart Tiered Cache Now Handles Anycast Cloud Origins

Cloudflare's Smart Tiered Cache has been a free, one-switch performance win since 2021 — pick the single closest upper-tier data center to your origin, and cache misses take the shortest path. But that logic falls apart when the origin lives behind an anycast or regional unicast IP, which is exactly how AWS, GCP, Azure, and Oracle Cloud expose their load balancers and front ends. The same IP looks equally close to dozens of Cloudflare PoPs, so the latency probes can't lock onto a real location. Smart Tiered Cache falls back to multiple upper tiers, which works but kills the cache efficiency you were after.

Today Cloudflare is shipping a fix: Smart Tiered Cache for Public Cloud Regions. You give it a cloud region hint (e.g., aws:us-east-1 or gcp:europe-west1), and it maps that hint to the right set of IP prefixes, then picks the best primary and fallback upper tiers for that region. No more guessing.

Why anycast origins are a problem

When your origin is a fixed unicast IP, Cloudflare probes latency from every data center and picks the fastest one as the single upper tier. All cache misses funnel through that one PoP, keeping hit ratios high and origin connections low. Anycast IPs break that: the IP represents the cloud provider's front-end network, not a single physical box. A probe from Chicago might show lower latency to an origin actually sitting in Singapore than a probe from Tokyo does, because the cloud provider's anycast routing answers from a nearby edge. Smart Tiered Cache then picks Chicago as the upper tier, and traffic from an Asian user goes: nearby Cloudflare PoP → Chicago → Singapore → back. That's a hairpin across two oceans.

Cloudflare had already added heuristics to detect anycast origins — if probe latencies from two checkpoints are faster than the speed of light would allow for a single location, the origin must be anycast. But the only safe fallback was to use multiple upper tiers, which diluted the cache benefit.

Region hints: the knob you turn once

The new feature lives in the Cloudflare dashboard under Caching > Tiered Cache > Origin Configuration. For any origin IP that Cloudflare has flagged as anycast, you click “Set Region Hint” and pick the cloud provider and region. That's it. Behind the scenes, Cloudflare fetches the latest IP range files from each provider every few hours, matches them against its 15-minute-updated upper-tier database, and computes a weighted vote per subnet. The upper tier with the strongest signal becomes the primary; primary and fallback always come from different PoPs. If a region has no probe data yet, it falls back to the closest Tier 1 PoP geographically.

The configuration is also available via API and Terraform, so you can bake it into infrastructure-as-code.

Bottom line

This is a targeted fix for a real pain point. If you run origins on AWS, GCP, Azure, or Oracle Cloud behind anycast IPs, you can now get the same single-upper-tier cache efficiency that fixed-origin setups have enjoyed since 2021. Cloudflare says more providers are coming. The only work on your side is setting the region hint — the probing, voting, and failover all run on their side.