[rootlocus]

> That the author got this recursive lookup so small that it broke everyone's brains is just more reason to be interested in this article.

https://github.com/jvns/tiny-resolver/blob/main/resolver.sh - the recursive lookup is 16 lines for + switch.

I'm sorry to say this, but if the recursive lookup can be implemented with a for and a 3-way switch that a CS 101 student can write, it's really not doing the heavy lifting. It may be interesting to know about it, it may be the case that multiple resolves don't have the implementation, but it's a trivial piece of code, let's not idolize it.

For me personally, having the power of hitting an endpoint and receiving useful information is really satisfying. Creating the request and parsing the reply are probably 90% of that process. And frankly, that was the first think I was looking for when I skimmed the article. "Are DNS replies really that easy to parse?". The fact that I need to make a switch on the reply and potentially make a recursive request somewhere else is trivial once you get the actual useful info from the remote.

I'm not criticising the article or the title. It's my opinion that parsing is more important, I'm not faulting the author. But I'm having a hard time accepting your arguments.

[tptacek]

It's not my argument that cs 101 students can't write recursive resolvers. Everyone can, and more people should, just like more people should write emulators, compilers, database engines, TCP/IP stacks, ray tracers, and computer algebra systems. Not because writing them is a huge achievement for humanity, but because people writing them and then documenting the process is vitally important for demystifying these things, in an era where most programming is just piping data from one database to another and we've lost touch with so much basic computer science.

My argument is that DNS codecs are not the interesting or tricky part of writing recursive resolvers.

Having had the pleasure of writing a bunch of DNS codecs, I'm having trouble even conceptualizing what's interesting about writing one. I don't think most people look at DNS and think "I could do this, but for the difficulty of constructing an NS record".