DNS is the silent force behind the internet. Without DNS (Domain Name System) you would have to visit every website by its IP address, and that simply doesn't work. But what exactly is DNS? And how can you get the most out of it for your website or web application at Theory7.net? In this extensive guide we answer all your questions and give you practical tips for setting up your DNS settings.

1. What is DNS?

DNS stands for 'Domain Name System'. You can think of it as the phone book of the internet. Your computer only understands IP addresses (for example 123.456.78.9), and DNS lets you reach a website through a readable domain name (such as yourwebsite.com) instead. The DNS servers automatically translate your domain name into the matching IP address.

1.1 How does the DNS process work, step by step?

  1. Entering the domain name: You type "yourwebsite.com" in your browser.
  2. DNS request: Your computer (or device) asks the right DNS server which IP address belongs to that domain name.
  3. DNS lookup: The DNS server looks up the IP address in its 'phone book'.
  4. Answer: The DNS server returns the correct IP address to your computer.
  5. Making the connection: Your browser loads the website from the IP address it found.

Without DNS you would have to remember every IP address yourself. The DNS system takes this tedious work off your hands.

Curious about the DNS setup Theory7 uses? Take a look at the post about our super-fast DNS server

2. Why is DNS important for your website?

2.1 Reachability and ease of use

Thanks to DNS, users don't have to juggle IP addresses. They simply remember a domain name, such as yourcompany.com or yourbrand.com, to visit your website.

2.2 Stability and reliability

DNS is spread across countless servers worldwide. If one fails, another server takes over. That way your website stays reachable (almost) all the time.

2.3 Flexible configuration

DNS lets you connect different services to one domain name. For example:

  • Website (A record or CNAME)
  • Email (MX record)
  • Subdomains (CNAME or A record)
  • Verification for external tools (TXT records for Google or Microsoft, for example)

With the right DNS settings you can connect your domain to all kinds of online applications.

3. The most important DNS records explained

3.1 A record

An A record links your domain name to an IP address (IPv4). This record is essential for your website to be reachable.

3.2 AAAA record

The AAAA record is similar to the A record, but for IPv6 addresses.

Tip: More and more hosting providers and internet providers use IPv6. It can be useful to set up an AAAA record as well if your server supports it. Theory7.net supports IPv6 by default.

3.3 CNAME record

With a CNAME record you point a domain name (or subdomain) to another domain name. For example, when your domain points to an external service such as Shopify or an email landing page through Mailchimp.

3.4 MX record

MX records (Mail Exchanger) determine where your email should be delivered. If you set this up incorrectly, you will no longer receive email on your domain.

3.5 TXT record

These records are often used for verification or security settings, such as:

  • SPF (prevents spam and phishing)
  • DKIM (cryptographic protection of email)
  • DMARC (protection against email abuse)

You can also use TXT records to verify services such as Google Workspace or Microsoft 365.

4. How do you set up DNS at Theory7.net?

4.1 Step 1: Log in to your Theory7.net account

Create an account or log in to your existing account.

4.2 Step 2: Go to 'Domains' and choose 'DNS settings'

Here you can manage all your DNS records, create and configure templates, and make backups of your DNS.

4.3 Step 3: Change the records you need

  • Click A record add or edit to link a new IP address.
  • Add a CNAME record for a subdomain.
  • Change or add MX records to set up your email traffic.
  • Create TXT records for SPF, DKIM or DMARC, for example.

4.4 Step 4: Wait for propagation

DNS changes don't become visible everywhere at once. DNS servers around the world need some time to pick up the updates. This process is called DNS propagation and usually takes a few minutes up to 24 hours. In exceptional cases it can take up to 48 hours.

Pro tip: Test your changes with a DNS lookup tool (for example with "nslookup" in your terminal or with online tools such as What's My DNS). That way you can see whether your new settings are already active.

5. Common DNS mistakes and how to avoid them

5.1 Wrong or missing MX records

Suddenly unreachable by email? Then your MX records may not be set up correctly or may have been deleted by accident. Check that the priority and the address are correct.

5.2 Wrong IP address

If your A record points to an outdated or wrong IP address, visitors end up on the wrong (or a non-existent) server. Keep the correct IP addresses at hand, especially if you have just moved to a new server or hosting package.

5.3 Duplicate records

Duplicate or conflicting records can lead to unpredictable behavior. Make sure you don't have two different A records for the same subdomain, unless you are deliberately using load balancing or advanced DNS solutions.

5.4 No SSL certificate on subdomains

Have you set up a subdomain, for example blog.yourdomain.com? Don't forget to extend your SSL certificate to it or set up a separate certificate. Otherwise visitors get an insecure connection warning.

6. Advanced DNS features

6.1 DNSSEC

DNSSEC (DNS Security Extensions) is an extension of the standard DNS protocol. It provides extra protection against DNS spoofing and cache poisoning. We support DNSSEC by default on .nl domains.

6.2 Anycast DNS

Anycast DNS means that your domain records are served from multiple server locations worldwide at the same time. This speeds up the response time for visitors, because the DNS resolver always connects to the nearest server.

Note: Anycast DNS is often a premium or enterprise solution, but it can contribute a great deal to the speed and stability of your website. Theory7.net uses Anycast DNS by default.

7. Why manage your DNS at Theory7.net?

  1. User-friendly interface: At Theory7.net you get a clear control panel. You don't need to be a technical expert to set up your DNS.
  2. Fast propagation: The Theory7.net DNS infrastructure is optimized for fast updates, so you don't have to wait unnecessarily long for changes.
  3. Extensive support: Stuck? The Theory7.net support team is there to help you, by email, chat or phone.
  4. Security and reliability: Theory7.net continuously invests in security and stability, so your DNS is always available.

8. Frequently asked questions (FAQ)

8.1 How long does it take before my DNS changes work?

In most cases changes take effect within a few minutes. Still, it can take 24 to 48 hours before all servers worldwide have been updated (propagation).

8.2 Can I manage my DNS elsewhere?

Yes, you can. You can use the nameservers of another DNS provider. Keep in mind that Theory7.net can offer less support if there are problems, because your DNS then falls outside our infrastructure.

8.3 Do I always need an MX record?

Only if you want to receive email on your domain. As soon as you have connected an email service (at Theory7.net or elsewhere), the MX record is required.

8.4 What is the difference between an A record and a CNAME record?

An A record points directly to an IP address. A CNAME record points to another domain name, which in turn can be linked to an IP address through an A record.

8.5 Can DNS affect the loading speed of my website?

Yes, to a certain extent. When you use fast DNS servers and/or Anycast DNS, the initial DNS lookup is faster, which slightly improves the total loading time. Still, loading speed also depends on other factors, such as hosting configuration, caching and the size of your website.

DNS is the backbone of the internet. Without this essential 'address book' it would be almost impossible to visit your website through a user-friendly domain name. At Theory7.net you can easily manage and optimize your DNS settings, whether you are a beginning blogger, a seasoned developer or an enterprising web shop owner.

By setting up DNS properly, you make sure your website is reliable, secure and quickly reachable, and it all starts with the basics: the right IP address and the right records. Need help? The Theory7.net team is ready to answer all your questions about DNS, domain names and hosting.

Start optimizing your DNS at Theory7.net today and give your website a stable, professional foundation online!