What is DNS, why is it important, and how to change it
DNS is one of the terms that you'll find recurring on the Internet, and despite its extreme importance, only a few truly understand it.
In this article, we will simplify the concept of DNS, and explain all its aspects; From what it is and how it works to how to change your site's DNS.
What is DNS
Domain Name System or sometimes Domain Name Service for short DNS is a system that we use all the time while browsing the Internet.
This system links the Domain to the IP Address so that we can browse through it without having to memorize the IP numbers of each site.
It was invented to make browsing easier for us, as computers only respond to numbers (I mean here the numbers of IP addresses), but we as humans are certainly unable to save the IP numbers of all the sites we use.
How does DNS work
There is more than one level to understand how DNS works and let's start with the simplest one of them first:
Imagine that you want to communicate with a colleague at work whose name you know, but unfortunately, you do not know his phone number, and because the phone only understands the language of numbers, you have to find his number, so you open the phone book of the city, and start searching for his name until you find the number and communicate with him.
This is exactly what I want to tell you about, for example, when you type the name of the site you want to access, for example, www.vilados.com, you will find that the browser takes you to the site directly without having to type the IP address.
So how does this happen?
Quite simply, the DNS system takes the name of the site or domain, and then goes to the database of all the domains and searches for the matching domain to know its IP and then directs you to it.
This is the simplest way to explain the topic, but it is certainly much more complicated than that and involves a lot of steps and there are many DNS servers working on this process.
So in order to fully understand how DNS works, we will first start with the types of DNS servers.
Types of DNS servers
There are 4 main types of DNS servers, which we need to know in order to understand how DNS works in detail, which are:
1. DNS Resolver
Determined servers are the first step in the journey of finding the IP address, and we can say that they are the intermediary between us or our computers and other DNS servers, as these servers will do the whole process as we will talk in detail shortly and will bring us the information we need.
These servers are for the ISP or the Internet Service Provider such as We companies in Egypt and STC in Saudi Arabia.
In the end, do not worry if you do not know how to distinguish between them, we will discuss in detail how they work shortly, and how they obtain the IP address, and the intention in identifying them at the beginning was not to get ambiguous when we talk about the detailed way of their work.
2. TLD Server
- Servers with generic domains, such as:.Com, .Net, .Org,.Edu, and others.
- Servers that carry international domains, such as:.Eg,.Uk,.The US, and others.
3. root server
4. Trusted DNS Server
Trusted servers are servers to which the intended servers are directed by TLD servers, which is usually the last step in the journey of finding the sites' IP address.
These servers store any information about domains and sites, including the IP address we are looking for.
DNS work steps in detail
Browsers and the Internet do not know how to deal with domain names. When you type in your browser www.vilados.com, the browser does not know what you mean.
Computers and browsers understand the language of numbers, and to access a site you need its IP address, so the DNS system was invented to translate from the domain name to the IP address.
We will now explain in detail how the DNS works by dividing its work into stages:
First Step: Make sure that the IP address of the link exists
When you type the link to the site in your browser, the browser checks whether the IP address of this site is cached or not, if it exists, it will redirect you to it, and if it is not communicating with the specified DNS server, DNS Resolver.
Step Two: Communicate with the DNS Resolver
If the IP address is not stored on your computer it will communicate with the established DNS server which is usually your ISP.
This DNS Resolver will check whether the IP address is present in its cache or not, if it exists it will send it to you, and if not, it will start the communication process with other DNS servers.
Step Three: Communicate with the Root DNS Server
If the IP is not stored on the specified DNS server, it will communicate with the Root DNS Server to find the IP address of the domain you entered.
Usually, the root server will decompose the URL or link you entered in this way into the main domain and subdomain.
For example, www.vilados.com will decompose it to the main .com domain and vilados sub-domain so that it can direct you to the correct Top Level Domain Server or TLP Server.
Step Four: Communicate with TLP
In the case of www.vilados.com, the root server will direct you to the TLP server responsible for the.Com domain, which contains within it all the servers responsible for sites ending in.COM
This server will not give you the IP address you want, but it will forward your Query request to the correct trusted server which will then give you the IP address of the site or link you entered.
Step Five: Communicate with the Authoritative DNS Server
This is the last step where after you are directed to the trusted DNS server, the server searches its database until it matches the domain or site you entered, and then gives you the required IP address.
This way you will be able to access the site you entered, surely wondering about those steps that take place and how long they take, and in fact, despite their many, they are done in fractions of a second.
How to change the DNS of your site
Here is a set of links to explain DNS change at the most popular domain name and hosting companies:
Post a Comment