What is DNS | How Does DNS work?

Most of us couldn’t fathom life without the internet nowadays. In fact, nearly 60% of the world’s population uses it. For perspective, that’s 4.66 billion people. Out of this number, most users access the web multiple times a day—and some are logged in online, at least in some capacity, all day. None of this would be possible, however, without DNS.

DNS Meaning?

DNS stands for Domain Name System. And it’s this system that makes the way we utilize the internet in our daily lives achievable. DNS is a hierarchical naming convention for devices, services, and other resources that connect to the World Wide Web. In essence, it’s like a phonebook for the internet.

Most users only recognize web addresses by their names, such as Google.com, YouTube.com, or Facebook.com. But computers and IoT devices can’t read human language. That’s where DNS comes in. DNS isn’t just a directory for web addresses, it also acts as a translator between computers and people by translating domain names into numerical IP (internet protocol) addresses. It is by a domain’s IP address that devices can connect with one another.

What is a DNS Server?

Of course, DNS isn’t just manifested out of thin air. It does have a physical location. The domain name system operates via DNS nameservers that are strategically positioned across the globe. These servers store all native files and DNS records for domains, which in turn, allows the servers to map domains to IP addresses.

How Does DNS Work?

Now let’s take a look at how the DNS process works. When a person types a web address into their browser, a query journey begins. Upon receiving the request, a recursive resolver either answers the query with information it already has in its cache or contacts a root server for an answer. The root server then refers the recursive nameserver to an appropriate top-level domain (TLD) server (com, net, org). The TLD then directs the recursive server to an authoritative nameserver, which provides the final answer to the original query. 

The query journey almost always ends at this point, but will repeat until the recursive server obtains the information it needs to answer the original request. Each server type (recursive, root, TLD, and authoritative) plays an integral role in the DNS process.

‍

DNS Record Types

In order for DNS to function properly, each domain must have DNS records. There are many different record types, but the most commonly used records are A, AAAA, CNAME, ANAME, SOA, MX, TXT (SPF), NS, SRV, and PTR records. Each record contains pertinent information about the domain and instructs nameservers on where queries should be delivered.

Not all records are mandatory but for your domain to be accessible online, it must have an A record for IPv4 addresses or a AAAA record for IPv6 addresses. Without an A record, servers wouldn’t know where to direct traffic for your domain. You also need to have a Start of Authority (SOA) record, as it’s required by RFC. If you are using a domain-based email, you’ll also need an MX record. 

Tip: Download our Record Cheat Sheet for a quick reference on the most commonly used records.

What is My DNS? 

If you want to know a domain’s nameservers or check your DNS records, you can perform what’s called a dig. This is done using a dig command in your computer’s terminal. You can also check your records with an online lookup tool, such as Contellix’s own DNS Lookup Tool. With this resource, you can retrieve record information, filter results by domain name, resolver, or record type, and you can even share a direct link of the reported information with your team. You can also perform lookups in 32 different locations around the world, and each lookup is queried against the authoritative nameservers you specify.

The TL;DR of the Domain Name System

While DNS may not be understood (or even known) by the average user, it is essential to the internet. The domain name system translates human-readable names into machine-readable IP addresses, and operates based on instructions within the DNS records for each domain. It allows all devices and resources to connect with one another on the web. Without DNS, our digitized world wouldn’t be so digitized.  

If you liked this, you might find these helpful:

https://activedirectorypro.com/use-nslookup-check-dns-records/

https://constellix.com/support/what-is-dns

https://internethalloffame.org/inductees/paul-mockapetris