Domains & DNS
Name resolution and the records that matter.
Domains & DNS is taught here in 3 lessons, running from How name resolution works through to TTL, propagation and common mistakes. Each lesson takes one topic, shows the working code, and links onward to the next, so the course can be read straight through in order.
| Track | Building a Website |
| Lessons | 3 |
| Level | Beginner |
| Reading time | about 39 minutes |
| Prerequisites | Helpful, but not required: SEO Basics |
Lessons
- How name resolution worksStub, recursive and authoritative servers, the path a lookup takes, and how to read dig output without guessing.
- Record types that matterA, AAAA, CNAME, MX, TXT and CAA - what each one does, how they interact, and where they collide.
- TTL, propagation and common mistakesWhat TTL really controls, how to migrate a domain safely, and the misconfigurations that cause outages.
More in Building a Website
SEO Basics Web Hosting CDNs & Caching Accessibility
FAQ
How long does the Domains & DNS course take?
It has 3 lessons, about 39 minutes of reading. Expect roughly twice that if you type out and run every example.
Do I need prior experience for Domains & DNS?
Not strictly. It helps to have read SEO Basics first, because some lessons build on it, but every lesson explains its own assumptions.
What should I read after Domains & DNS?
Continue with Web Hosting (3 lessons), the next course in Building a Website.
Last refreshed 2026-09-18.