zlacker

You could also in theory use the originating IP of the DNS requests themselves. But Cloudfare messes up that as well:

https://twitter.com/archiveis/status/1018691421182791680

> Absence of EDNS and massive mismatch (not only on AS/Country, but even on the continent level) of where DNS and related HTTP requests come from causes so many troubles so I consider EDNS-less requests from Cloudflare as invalid.