DNS Explained: What It Is and Why It Matters for Your Domain

What DNS Actually Does

When you type google.com into your browser, your computer doesn't know where to send the request. It knows the name, but not the address. DNS (Domain Name System) is the phone book that translates "google.com" into an IP address like 142.250.80.46.

This lookup happens in milliseconds, invisibly, every time you visit any website. It's one of the most critical pieces of infrastructure on the internet.

The DNS Hierarchy

DNS is organised as a tree. At the top are the root servers (there are 13 logical root servers, operated by organisations like ICANN and Verisign). Below them are the TLD servers (.com, .no, .de). Below them are your domain's nameservers.

When you register a domain, you tell the TLD servers: "for this domain, ask these nameservers." Your nameservers are then authoritative — they hold the actual records.

The Record Types You Need to Know

A Record: Maps a domain name to an IPv4 address. This is how your domain points to your web server. Example: example.com → 104.21.14.11

AAAA Record: Same as A, but for IPv6 addresses.

CNAME Record: Maps a subdomain to another domain name (not an IP). Commonly used for www. Example: www.example.com → example.com

MX Record: Specifies the mail server for the domain. Without correct MX records, email to your domain won't work. Example: example.com mail goes to mail.google.com

TXT Record: Free-form text record. Used for domain ownership verification, SPF (email authentication), DKIM, and DMARC. Example: "v=spf1 include:_spf.google.com ~all"

NS Record: Specifies the authoritative nameservers for the domain. Changing NS records changes where DNS is hosted.

SOA Record: Start of Authority — technical metadata about the zone. Usually auto-managed.

TTL: Why Changes Take Time

Every DNS record has a TTL (Time To Live) measured in seconds. This tells DNS resolvers how long to cache the record before checking for updates.

A TTL of 86400 means records are cached for 24 hours. If you change an A record, it can take up to 24 hours to propagate globally.

Before making major DNS changes (transferring domains, moving servers), reduce your TTL to 300 seconds (5 minutes) 24–48 hours in advance. This minimises the propagation window.

Nameservers vs DNS Records

These are often confused: - Nameservers (NS records) tell the internet where to look for your DNS records - DNS records (A, MX, CNAME, etc.) are the actual configuration

If you use Cloudflare for DNS, your nameservers point to Cloudflare (ns1.cloudflare.com), and you manage your A, MX, and CNAME records in the Cloudflare dashboard.

If you use your registrar's DNS (default for most), your nameservers point to the registrar, and you manage records there.

The Most Common DNS Mistakes

1. Forgetting MX records when moving domains — email stops working 2. Not reducing TTL before changes — 24-hour downtime window instead of 5 minutes 3. Adding a CNAME for the root domain — root domains can't be CNAMEs (use ALIAS or ANAME records, or A records) 4. Deleting existing records when adding new ones — always check what exists before editing

Should You Use Cloudflare for DNS?

For most websites: yes. Cloudflare's free DNS tier is fast (one of the fastest in the world), reliable, and adds DDoS protection at the DNS level. Switching your nameservers to Cloudflare doesn't change your registrar — you can register at Namecheap and use Cloudflare DNS simultaneously.

The main reason not to: if you need very specific DNS features that Cloudflare's free tier doesn't support, like GeoDNS or complex weighted routing.