Blocks some DNS resolvers. The person running it has some weird bone to pick he doesn't like that Cloudflare doesn't forward the requests subnet but only blocks Cloudflare not the dozens of other DNS resolvers that don't support it.
They actually don't even block they intentionally give bad ips back.
IIRC their argument is something like, they're acting exactly according to spec and Cloudflare is doing something weird/not according to spec that just happens to work everywhere else.
Nah the EDNS Client Subnet is explicitly optional and the RFC makes it very clear you're not required to implement it. They are very open that they, archive.is, are violating the spec. They maybe could justify a SERVFAIL but instead they just lie in the response.
It's actually funny from time to time archive.is works just fine via cloudflare I'm assume when whatever IP list archive.is is using happens to be missing some of cloudflares addresses. You can tell they use a specific cloudflare targeting list because issuing a DIG from you local computer without the EDNS Client Subnet works perfectly fine.
