What is DNS and How Does it Work?

DNS (Domain Name System) is the backbone of the internet. It‘s like an address book that matches human-readable domain names to machine IP addresses.

When you type https://example.com into your browser, DNS translates "example.com" into a numeric IP that computers use to find the server hosting that website.

Without DNS, you‘d only be able to access websites by typing in cryptic IP addresses like 192.168.1.1!

A Beginner‘s Guide to the DNS Process

Here‘s a simple 4-step process to understand how DNS works:

1. You type "example.com" into your browser and hit enter. Your computer first checks its local DNS cache to see if it already has the IP address associated with example.com. This local cache helps speed up repeat website visits.

2. If no record is found locally, your computer sends a DNS query to your Internet Service Provider‘s (ISP) recursive DNS server. This server acts as an intermediary between you and the greater internet.

3. If the ISP‘s DNS server doesn‘t have the IP address cached, it makes a request upward to the DNS root servers. These 13 main root servers point to the Top Level Domain (TLD) DNS servers, in this case .com.

4. The .com TLD servers then point to example.com‘s authoritative name servers which store the official IP address for the domain. Once found, the IP is cached locally on your computer and the website loads.

So in summary, DNS acts as a decentralized phonebook, translating domain names to IPs so you can access websites by name.

Common DNS Record Types Explained

There are many types of DNS records that serve different purposes:

A Records

The most common, an A record maps a domain name to an IPv4 IP address. This allows visitors to find your website.

AAAA Records

Maps a domain to an IPv6 address. IPv6 is the newest version of IP, but isn‘t fully adopted yet.

CNAME Records

Used to create an alias for your domain. For example, you can map "www.example.com" to point to "example.com".

MX Records

Direct emails to your mail server by specifying the domain‘s mail exchange.

TXT Records

Allow you to insert text notes into your DNS which are often used for email authentication.

Why Choose a Third-Party DNS Provider?

By default, your domain‘s DNS is managed by your registrar (where you bought your domain name) or web hosting provider.

But for better performance and functionality, third-party DNS providers like Cloudflare or AWS Route 53 have many advantages:

• Speed: Third-party DNS is cached globally, leading to faster website load times for your visitors worldwide. This can improve your site‘s search engine rankings.

• Reliability: Provider with 100% uptime guarantee versus relying on your web host‘s DNS which may go down.

• Security: DDoS protection, traffic filtering, and other features to protect your site from attacks.

• Flexibility: Advanced DNS management options like geo-routing, failover, and easy API access.

According to Cloudflare, switching to their DNS made sites 24% faster on average.

Step-by-Step Guide to Changing DNS Servers

Many people are hesitant to change DNS providers because it seems complicated. But the process is actually quite simple:

1. First, log into your domain registrar account (where you purchased your domain name).

2. Look for the nameserver (NS) records section. This shows you which DNS servers your domain is pointed at.

3. Change the NS records to your new third-party provider‘s nameservers. Every DNS host provides the info you‘ll need.

4. Scroll down and click save. The DNS changes can take up to 24 hours to fully propagate worldwide.

And that‘s it! The new DNS servers will now manage DNS queries for your domain.

Real-World Examples of DNS Configurations

To give you a better idea of how DNS is configured, here are two common examples:

Using Third-Party Email with Google Workspace

Let‘s say you want to use Gmail or Google Workspace for your custom email address like [email protected].

You‘d start by signing up for Workspace and adding your domain.

Google will provide the MX, TXT, and CNAME records needed to route emails and authenticate your domain.

Simply add these DNS records at your registrar to point your domain‘s email to Google‘s servers.

Setting up CDN and HTTPS

Content Delivery Networks (CDNs) like Cloudflare speed up your site by caching static resources across global edge servers.

By changing your NS records to Cloudflare, you can also provision free SSL certificates and enable HTTPS security on your site.

Cloudflare handles the technical details – you just reroute DNS to their nameservers.

Troubleshooting Common DNS Issues

In 15+ years as a webmaster, I‘ve seen some common DNS issues crop up:

• Typos when changing DNS records can lead to misconfiguration. Double check your entries.

• DNS changes take time to propagate globally. Be patient for up to 24 hours for the switch to fully take effect after changing nameservers.

• Make sure your web host and domain registrar are pointing to the same DNS servers for consistency.

• Flush your local DNS cache if your computer still shows the old IP address after DNS changes are live.

Hopefully this beginner‘s guide provided you a good overview of what DNS is, how it works, and why it‘s important for accessing websites reliably and quickly.

Let me know if you have any other questions!