How does your computer find websites

Ok, I've worked with computers almost my entire life but today was the day I decided to find out how my browser goes from me entering a url into the search field to actually finding the page.

DNS resolution flow: a web browser asks a local resolver, which checks its cache and then queries a root nameserver, the TLD nameserver, and the authoritative nameserver, which returns the IP address back through the resolver to the browser so it can connect to the website

I couldn't have done it without my trusty companion named Bard¹. A bit slow², but it knows its stuff.

Ok here we go!

Let's start with the basics: What is a DNS?

Bard's answer explaining what DNS is

Ok, that's interesting, so What are the major DNS providers?

Bard's list of the major DNS providers

Super interesting! So How does your resolver know which DNS provider to use for a specific domain?

Bard explaining how a resolver knows which DNS provider to use for a domain

Ok, let's see how far you can go, Bard (❤️): Can you show me the path my local resolver takes to reach the authoritative DNS provider for this domain: schmittsfn.com

Bard's description of the path a local resolver takes to reach the authoritative DNS provider for schmittsfn.com

Worth a try. Let's stick to information only. Next: How do you visualise the steps a resolver takes to retrieve the IP of a domain?

Bard's visualization of the steps a resolver takes to retrieve a domain's IP address

Got the picture now! Let's get down to the nitty gritty: Where is my local resolver on Mac?

Bard's answer on where the local resolver is on macOS

Cool, cat /etc/resolver/resolver.conf

Terminal output of cat /etc/resolver/resolver.conf

Might have changed. I'm on macOS Ventura. cat /etc/resolv.conf

Terminal output of cat /etc/resolv.conf

scutil --dns

Terminal output of scutil --dns

(I don't really know what information is generic in the above screenshot but I went for "safe")

Ok I think we're done!
Here's the gist of it:

One detail in the screenshots is simplified: your local resolver and the recursive resolver are not always the same thing.

Your computer asks a system resolver to resolve the domain. That local resolver usually forwards the question to a configured recursive resolver, often your router, your ISP, or a public DNS service. If the answer is not cached, the recursive resolver follows the DNS hierarchy: root nameservers, TLD nameservers, then the authoritative nameservers for the domain. It returns the IP address, and your browser can connect to the website.

Hope this helps!

¹ Bard, a large language model from Google AI
² I'm sure that's going to change