[zamadatix]

That's "how" not "why". Most major services tailor queries based on the source IP, for some reason when archive.is does it to cloudflare queries it's either broken or purposefully broken. At first I thought it might be something to do with 1.1.1.1 in the archive.is network but then I noticed cloudflare queries on behalf of clients don't even source from that IP.

[topynate]

See here: https://twitter.com/search?q=from%3Aarchiveis%20cloudflare&s...

Archive.is intentionally returns bad results to Cloudflare DNS, because Cloudflare don't send them the EDNS Client Subnet Header. Archive.is haven't said much about why, but what they have said appears to accord with this blog post: https://www.sajalkayan.com/post/cloudflare-1dot1dot1dot1.htm...

[compuguy]

Apparently he discards requests from DNS servers that don't send EDNS in their requests: https://twitter.com/archiveis/status/1018691421182791680