21 Comments
User's avatar
Dr Sam Illingworth's avatar

Thanks Erich, that was a super clear explanation of something that I have been playing around with recently in trying to capture email addresses for an app I am building. Now I know what the hell DNS means and does. 🙏

Erich Winkler's avatar

Thank you, Sam! I appreciate it! I plan to create an advanced version of this article and describe the various types of DNS. It can get really complicated, but you need to understand the basics first.

That’s cool. What kind of app are you building?

Dr Sam Illingworth's avatar

Thanks Erich. Just playing with an audit for higher education assessment and AI. You can see it here: https://github.com/sam-illingworth/Integrity-Debt-Audit Still very much in beta testing!

Erich Winkler's avatar

Wow! I had to check it out later today! I had no idea you create apps too!

Dr Sam Illingworth's avatar

Thanks Erich, I am getting back into coding after a loooooong (decade) hiatus!

Erich Winkler's avatar

Well, it’s been 3 years since I stopped coding, and I feel rusty already!

Marco Lelli's avatar

Good job! In a world where everyone in IT Is looking at the Clouds, this back to the roots Is Gold.

Erich Winkler's avatar

Thank you, Marco! I appreciate it!

In my experience, understanding the basics is where the real knowledge lies :)

Marco Lelli's avatar

Absolutely agree, Erik.

That mindset is why I started Legacy Things. DNS definitely on my list for future posts.

https://legacythings.substack.com/?utm_source=share&utm_medium=android&r=7oz2wp

Interisle Consulting Group's avatar

This is the canonical form of name resolution.

I'd add that most queries are answered by recursive resolvers that are typically configured to cache answers from authoritatives.

Caching is essential for performance.

Client or stub resolvers can cache.

But their purpose is to ask DNS questions.

Recursive name servers most often answer DNS questions from answers to questions they e already asked authoritiatives.

Authoritative name servers are the publishers of intended domain name information.

Erich Winkler's avatar

Great points, thanks for adding that.

You’re absolutely right, caching is what makes DNS fast and scalable in reality. I simplified it to the canonical flow to help beginners build the mental model first, as I believe adding too many details at the beginning makes it hard to understand the core mechanism.

Would you be interested in a follow-up focused on caching and its security implications?

Interisle Consulting Group's avatar

I think your audience might benefit from it. DNS traffic and behavior is integral to our research so I'm happy to comment.

You might also explain how integral the DNS is to web and app services. Few people realize just how many DNS requests are processed to gather the objects needed to render a single web page.

Erich Winkler's avatar

That’s a great addition, thank you.

You’re absolutely right. DNS is far more integral to web and app functionality than most people realize, especially the sheer volume of queries behind loading a single page.

I’ll pronably focus on this with a follow-up focused on caching. I plan to create a post that describes what really happens when you visit a website through your browser.

Thank you for your tips!

Michael's avatar

Thanks Sir

Erich Winkler's avatar

I am happy to help! Feel free to reach out to me with any questions!

Lonely Bhutan Tours & Treks's avatar

Very informative 👏

Erich Winkler's avatar

I am happy to hear that! Understanding these concepts is crucial for any cybersecurity professional. Is there anything you’d add?

Jashmine P's avatar

This is a great explanation. You stripped away the jargon and walked through the flow in a way that actually sticks, especially the resolver → root → TLD → authoritative sequence. Perfect foundation for anyone moving into cybersecurity.

Erich Winkler's avatar

Thank you, Jashmine! I appreciate it. That was indeed my goal from the beginning. Understanding these basic networking concepts is non-negotiable for any cybersecurity professional.

Chris #TheAntiVirusGuy Moody's avatar

A great explanation of DNS. I didn't know all the details you went into, so I've learnt something today.

Erich Winkler's avatar

Thank you, Chris! I appreciate it. I tried to make it easy to understand, regardless of the reader’s background.