Wait...

Something is missing here!

How could the resolver find 'ns1.dnsimple.com' before 'dnsimple.com'?

Since 'ns1.dnsimple.com' is a subdomain of 'dnsimple.com', how could we resolve 'ns1.dnsimple.com' without resolving 'dnsimple.com' first?

Isn't the search going backwards?

Wouldn't we get stuck in a loop at some point?

For example, let's say that the authoritative server for domain.com is ns1.domain.com

If I wanted to browse domain.com, the .COM TLD would tell me to get the IP address from the authoritative server: ns1.domain.com

Go ask ns1.domain.com

ns1.domain.com is a subdomain of domain.com

We cannot get to a subdomain without getting to the domain first!

Stuck in a loop!

So, what happened? How come the resolver was able to find 'dnsimple.com' through 'ns1.dnsimple.com'?

Simple!

Glue records!

Glue records?

Exactly!

Awesome!

I'll explain then!

When the resolver asked the .COM TLD about dnsimple.com, extra information was attached to that response.

The resolver got at least one IP address for each name server.

We call that the glue!

So the resolver not only got the name of the authoritative name server, it also got the IP address.

Thus breaking the circular dependency.

Nice! I understand it now!

Glue records rock!

Yes, they do!

hahaha, thanks!

You made it through the end! Now is a good time to watch the video that we made for this comic!

Watch this short animation based on this comic. They finally have a voice!