[nijave]

We had rate limiting with Istio/Envoy but Envoy was using 4-8x normal memory processing that much traffic and crashing.

The attacker was using residential proxies and making about 8 requests before cycling to a new IP.

Challenges work much better since they use cookies or other metadata to establish a client is trusted then let requests pass. This stops bad clients at the first request but you need something more sophisticated than a webserver with basic rate limiting.

[Aachen]

> The attacker was using residential proxies and making about 8 requests before cycling to a new IP.

So how is Cloudflare supposed to distinguish legitimate new visitors from new attack IPs if you can't?

Because it matches my experience as a cloudflare user perfectly if the answer were "they can't"

[nijave]

Captcha/challenges and tracking users/IP rep across the web

They also do IP and request risk scores using massive piles of data they've collected