We’ve got a lot of complex topics to cover here, so for the sake of simplicity we’re only going to touch on the really high level basics of these concepts to help you understand how all these different pieces of the puzzle are connected together. When you’re first getting started in the world of IT, it’s often a bit of a puzzle how all these things are plugged together under the hood which can cause a lot of confusion. By knowing how things are plugged together, i.e. how the internet works, you will have a significantly better chance of working with existing setups, debugging problems fast, and most importantly building new solutions to bring your creative ideas to life.
Firstly, let’s get some basic terminology understood;
- Registrar = This is where you purchased your domain name from, i.e. example.com
- Nameservers = This is the where the authority starts for your domain, i.e. it’s the equivalent of “tell me who I need to talk to who can point me in the right direction to get to where I want to go”. It’s the authority on the subject whose opinion on the matter is #1.
- DNS = This is the gate keeper to determine how traffic into your domain flows to where it needs to go. Think of your DNS like Heimdall from the Thor movies. You configure your nameservers to act in a way that you want, i.e. requests from www.example.com, should ultimately route to server IP address, 1.2.3.4, so that you don’t need to go remembering a bunch of IP addresses like a robot – or in the Heimdall world, “Heimdall…” as Thor screams in the movies, and he is magically transported from Earth to his home world of Asgard. Likewise, if Loki wants to visit a different planet, he just asks Heimdall to send him there and the magic happens. DNS can appear like magic at times, but it’s actually really simple once you understand it. DNS is a hard concept to explain simply, we’ll do another blog post on this topic in more detail another time. Hopefully this basic comparison helps you to at least grasp the topic at a high level.
- Servers = This is where things get fairly messy. This could be a physical piece of hardware that you can touch and feel, or could be a virtualised system, or visualised system within a virtualised system. There are multiple layers of virtualisation when you get down to this level. Although it’s not that important for the purpose of this blog post. Ultimately, all we care about is that the traffic from www.example.com, or something-else.example.com, gets to where it needs to when someone requests this in their web browser.
As mentioned, this is a difficult concept to explain simply in a blog post as there are so many different considerations that need to be made. But hey, let’s give it a go, with a basic diagram. There are elements of this diagram that have been simplified to help you understand how the different bits fit together.
So here’s how it works step by step. For those of you who are more technical than this blog post is aimed at, yes there are a few steps in between things that have been cut out for simplicity.
Step 1 – Type Website Address into Web Browser
This step is fairly basic so we’ll skip over this one.
Step 2 – Web Browser Asks for Authoritative Nameserver for Website
This part is very complex in the background, so we’re not going to delve into these details. For the purpose of simplicity, ultimately your web browser says “Give me the name servers for contradodigital.com”, and ‘the internet’ responds with, “Hey, sure, this is what you’re looking for – ns1.contradodigital.com and ns2.contradodigital.com”.
As with all hostnames, they ultimately have an IP address behind them, so this is what then forwards the request onto the next step.
Step 3 – DNS Provider with Hosted Zones
A Hosted Zone is simple something such as contradodigital.com, or something-else.com. Within a Hosted Zone, you have different types of DNS Records such as A, AAAA, CNAME, MX, TXT, etc. (that last one isn’t an actual record, just to confirm 🙂 ). Each of these record types do different things and are required for different reasons. We’re not going to be covering this today, so for simplicity, the A Record is designed to forward the request to an IP Address.
So your DNS Provider translates your request for www.contradodigital.com into an IP address where you are then forwarded.
Step 4 – Web Hosting Provider Serves Content
Finally, once your web browser has got to where it needs to get to, it starts to download all the content you’ve asked for from the server on your web hosting provider to your web browser so you can visualise things.
This part of the diagram is so overly simplified, but it is fine for what we are discussing. The reality of this section is that this could quite easily be 10-20 layers deep of ‘things’ when you start to get into the low level detail. But that’s for another time.
If you want to get a feel for how complex just part of this area can be, we did a blog post recently explaining how Your Container Bone is Connected to Your Type 2 Hypervisor Bone.
Summary
Hopefully this blog post has given you a good understanding of how your Registrar, Nameservers, DNS and Servers are connected together under the hood. When you truly understand this simple approach, play around with a system that isn’t going to break any live environment, so you can start to test different types of configurations along the way to see how they behave. If you don’t know what you are doing, do not play around with these things on a Live system as you can do some real damage if you get things wrong which can result in your services being offline for a significant period of time.
Michael Cropper