Something that started as a small curiosity and weekend project turned into a long article with several surprises for myself (including how bad I am at time estimates). I went down quite a few rabbit holes along the way.
EDNS Client Subnet in Practice: Evaluating Public Resolver Behaviors:
https://farrokhi.net/posts/2025/10/edns-client-subnet-in-practice-evaluating-public-resolver-behaviors/
