What DNS is, and How It Works


By: Drew Germyn

Categories: Technology

Nowadays, it seems like the thing that is really making the world turn is the internet.  The online web has become integral to every aspect of our lives; it’s how we entertain ourselves, what we use to learn new things, how we stay connected to current events, and even how we pay our bills and manage our finances.  The Domain Name System (DNS) makes staying plugged in exponentially easier, and the chances are that you’re already relying on it a lot more than you might think.

What Exactly Is DNS?

The internet runs off of IP addresses.  These are very much like physical addresses for every computer or device that’s hooked up to the internet; they usually consist of a string of 4 numbers (ranging from 0 to 255), separated by periods.  Every website has an IP address associated with it, and that’s what our devices are looking for when we want to navigate from page to page on the internet.

Why Not Just Use IP Addresses?

There are over 4 billion possibilities for IP address combinations, and remembering endless strings of numbers is extremely difficult.  That’s where DNS comes in!  DNS takes the domain name of the site you’re attempting to reach- like Google.com or Facebook.com, for example- and searches for the IP addresses that are linked with that domain.  This enables us to stick with linguistic names (rather than numerical codes) for our websites, which are much easier for us to remember and associate with.  Think of it like searching through your contact list… you may not know everyone’s phone number by heart, but you can type in their name, and your device brings up the information for you.  DNS does much the same thing with websites.

How Does DNS work?

It seems like DNS is a one-step process, as it works pretty instantaneously; we can enter a domain name into the search bar of our browser, and within the space of a second or two be taken directly to that website (or to a search engine).  But there are actually several steps that DNS goes through to make sure we’re navigating to the correct place.

The DNS Process

Let’s say you want to post something on Facebook.  The first thing DNS will do is check your device to see if it knows Facebook’s IP address.  Usually, it will not, as adding the IP address of a specific website or computer is something that is generally done manually.

Upon failing to find an IP address in your device, DNS will then check out your recent local DNS caching.  DNS caching is when websites, etc. that you have recently visited are saved on your device; this makes it, so you don’t have to make a lookup every single time you want to visit a site.

The third step DNS takes (if the local cache fails), is to perform a query to a Recursive DNS Server.  Most Internet Service Providers will provide this type of server, so it’s not anything you need to worry about acquiring on your own.  Generally, a Recursive DNS Server will have access to the domain address you need, and the process ends here.  Occasionally DNS will need to go a step further and locate a root DNS server, which is run by only a small handful of companies throughout the world. All of these steps are processed in milliseconds so that you can have instant access to whatever information or website you need.

DNS Records and What They Mean

DNS makes use of a number of different records to help keep information organised and easily accessible.  Here is a quick list of the various record types you would encounter while working with DNS.

A-Record: This record plots the way to an IPv4 address.  Essentially, this is what points to the specific domain name to an IP address.

AAAA-Record: This record does the same thing as an A-Record, but contains mapping for IPv6 addresses, which is newer and will become more commonly used as technology moves forward.

CNAME (Canonical Name):  This record redirects DNS to a secondary domain (or subdomain) that is hosted on the same IP address, and is easier to use than adding a second A-record.

DNSKEY and DS:  These records are vital to help increase the security of your website.  They are used to establish DNSSEC trust, where DNSSEC is a set of protocols that increases the safety in your domain name system.

MX (Mail Exchange):  Sort of like a postal system, the MX record tells incoming email where to go.

NS:  The NS here stands for name server.  Name server records are what establish the name server for any given domain, and some domains may employ several at once (for example, Google uses four different NS records).

PTR:  PTR works to essentially reverse DNS… it sends you back to the name of the record.

SOA: This is required of every domain zone.  SOA will contain the primary name server of your domain, the hostmaster, a serial number (this will change as your domain is updated), a set timeout that determines when your zone should refresh, a set time for expiration, and another time for how long a record that is no longer to be found should remain cached.

SRV: SRV are somewhat more generalised, and they direct DNS towards specific services.

TXT: You may have already guessed this one… TXT stands for text and is a textual record.  There is a wide variety of use classes (DKIM and DMARC, for example) and they are extremely common.

How Does DNS Help My Company?

DNS is what enables your company’s website to be instantaneously reachable by anyone who knows your domain name, the name of the company itself, or even just what service you happen to provide.  A potential client can enter any of these into the search bar on their browser and be immediately directed to your homepage, or to a search engine that has your page listed.  Without DNS, anyone looking to find your homepage would need to have your precise IP address.

Why Choose Localnode?

Localnode is a first-class hosting platform that provides a stable domain for all of your company’s digital needs, for a better value that you’ll find anywhere else.  With Localnode, you have access to a superior network as well as superior software that makes staying connected to your client base much more streamlined and simple.  Localnode also boasts superior hardware that ensures your website will run smoothly, quickly, and efficiently, without risking overcrowded servers.

If your company has any digital or online component, at some point you’ll likely have to work with DNS.  Hopefully, this article has helped to clear up a bit of what the Domain Name System is and how it works so that you can use DNS to help your company grow to its greatest potential.