This is a type of common HN post. Where the person posting is going over well known knowledge. Others that are similar are "I wrote a compiler." and "I made a e

This is a type of common HN post. Where the person posting is going over well known knowledge. Others that are similar are "I wrote a compiler." and "I made a emulator." Usually they are subsets of the problem space and sometimes quite often don't demonstrate any expert knowledge of the subject. Perfectly fine personal projects, but hard to understand why they're worth blogging about. And FWIW, DNS absolutely propagates in a push fashion in circumstances where people are running large DNS installations with multiple authoritative servers.