DNS Basics for Website Owners & Developers

What you need to know about DNS

The Domain Name Service (DNS) is a critical part of the internet, and is what glues domains together with website, email, and more.

For most site owners and many website developers, DNS remains mysterious, not very well understood, yet something that must be dealt with at some point. Lack of a basic foundation for understanding DNS leads to hours of wasted time, accidental downtimes with sites, email delivery problems, and much frustration.

This page is meant to help solve that problem. It is written to provide concise, easy to understand, yet sufficiently detailed information, so you'll have a basic but solid foundation for when you need to deal with DNS.

You should read our page on Domains and the Four Service first, if you don't yet know the basics about domain registration, and the relation of Domain Registrars to DNS Providers, Website Hosting, and Email Hosting.

Overview

What is DNS

How DNS works

DNS Basics

Zone / List of records

IP Address, Names, and More

Record Types

Providers

Registrar

Hosting Provider

Cloudflare

DNS Caching / Propagation

TTL

Checking DNS

Authoritative Queries

Online tools

Command-line tools

HTTPS / TLS Certificates

Common Tasks

Setting up new website

Switching Hosting

TTL

Ordering of changes: SPF, TTL, CNAME, A, NS

Setting up Email

Splitting Email / Website Hosting

Incoming Email

MX record, priority, Hostname vs. IP

Outbound Email

SPF, DKIM, DMARC

cPanel DNS

The cPanel Problem

Junk Records

Hybrid Services

Domain Forwarding

Domain Parking

More Tools

MX Toolbox

Common Mistakes

Setting Nameservers w/o zone

Not changing A record before NS

www

Multiple / Different A records

Mixed nameservers

Less Common Mistakes

AAAA records

DNSSEC