Strategy Manager for Fixed Connectivity, Vodafone Business
There’s no doubting the brilliance of the Internet.
As a 20th century invention, it shines as brightly as the car and the zip when it comes to changing the world in which we live. The name Internet is really a wrapper for a whole host of technologies that work together in unison to let you stream videos, send emails and buy anything your heart desires.
The Internet is the victim of its own success though.
When it was conceived, the inventors couldn’t have imagined that it would grow to become as omni-present as the telephone. There were hundreds of connected computers at most, so it wasn’t that hard to keep track of them. Fast forward 50 years and there are now almost 5 billion people using the Internet and another 7 billion connected devices on top of this.
If I tell you that every device that connects to the Internet needs an address, you can see the challenge of scale.
Sometimes, we can use network address translation (NAT) techniques to allow devices to share addresses, but they still need an address to share. Most IP addresses are in the form of four numbers, separated by full stops. These aren’t the most memorable of constructs, so the Domain Name System (DNS), was invented to allow us to use names instead.
What is DNS?
To put it simply, DNS is the global phone book for the Internet1. It contains a list of user friendly domain names that you’ll be familiar with, such as google.com, amazon.com and vodafone.com.
It links these names to their IP addresses so that we don’t need to remember all of them. It also allows us to build in resilience – we can use more than one address for these names, and this means that if one part of the service breaks, the name can still be reached. As an example, amazon.com has three separate ‘A’ or ‘Address’ records and we can use any of them to connect to the web page.
DNS doesn’t just simplify your web browsing though. It is absolutely crucial to the operation of just about every internet service.
Take e-mail… each time you send an email to someone across the Internet, DNS is called into play. Every email address is in the form: <recipient>@<domain name>. The domain name needs to be turned into an IP address for the email to be delivered.
This translation from name to address happens through the global DNS service – without it, you wouldn’t receive that really important email telling you that the meeting details have changed and you’re about to be late!
So, how does it work?
DNS operation is based on the principle of recursion. Basically, if the server you’re asking doesn’t know, it will ask the next in line and keep doing this until you’ve got your answer. The structure is hierarchical in nature, meaning that the next server in line is actually the one above. See what I mean below:
So, let’s say we asked our local DNS server for the address for www.vodafone.com. It might not know itself, so it will ask the next level up if it knew. Sometimes, we need to go to the very top of the DNS tree and ask the ‘root’ name servers.
These are some of the most important computers in the entire world. Without them, the majority of the world's Internet traffic would disappear down a black hole, never to be seen again.
Why should you care about DNS?
By now, I'm sure you know the answer. DNS is a fundamental part of the fabric of the Internet and without it, almost nothing works. DNS is often bundled with internet connectivity so it’s important to understand how your provider is set up.
If your DNS service goes down, you won’t be able to:
type www.google.com into your web browser and get a search page any longer, or
send emails to people outside of your organisation; or
access your cloud workloads that are running in Internet-connected data centres.
These are just some of the impacts of a DNS issue.
At Vodafone, we understand the critical nature of DNS. Our servers respond to over 5.5 billion queries every day (5,507,317,766 last time I checked) and we are responsible for the details of more than 10,000 domains. When you consider that each domain can have upwards of 100 records, that’s a lot of responsibility.
Customers trust us with their business-critical information, and we treat it with the respect it deserves. It’s time to make sure your provider does the same.