WHAT IS DNS AND HOW DOES DNS SERVER WORKS?
Unfortunately, many individuals don't understand what exactly DNS is. This article is for them and for anyone else that wants to learn about DNS.
Here, we could spend hours going into each and every detail, but we're only explaining basics here. Let's begin.
WHAT IS DNS?
The Domain Name System is indisputably one of the most important and over-looked part of the internet. Without DNS, the internet that we know today would collapse, and we would all be licking stamps to pay our bills, driving to an actual store to purchase something, reading the newspaper to see what movies were showing, or buying little round pieces of plastic called CDs to get our music.
Will the internet 'work' without DNS? Absolutely not. Will it be an utter pain? Probably - and if DNS broke tomorrow, a lot of services on the internet would be broken.
In the world of networking, computers don't go by names like human do, they go by numbers because that is how computers and other similar devices talk and identify with each other over a network which is by using a number called IP addresses. Humans on the other hand are accustomed to using names instead of numbers. Whether he's talking directly to another person or identifying a country, place or thing. Humans identify with names instead of numbers.
So, in order to bridge the communication gap between computers and humans and make the communication align easier. Networking engineers developed DNS and DNS stand for Domain Name System and DNS resolves name to numbers. To be more specific, it resolve domain names to I.P addresses. So if you type in a web address in your web browser, DNS will resolve the name to a number because the only thing computers know are numbers. So, for example, if you wanted to go to a certain website. You will open up your web browser and typed in the domain name of that website.
For example, let use facebook.com, now technically, you really don't need to type in the facebook.com to retrieve the Facebook web page, you can just type in the IP address instead if you already knew what the IP address was but since we are not accustomed to dealing with numbers especially when there are millions of website on the internet, we can just type in the domain name instead and let DNS convert it to an IP address for us.
So back to our example, when you type in facebook.com in your web browser, the DNS server will search through its database to find a matching IP address for that domain name and when it finds it, it will resolve that domain name to the IP address of the Facebook website and once that is done, then your computer is able to communicate with the Facebook web server and retrieve the web page.
So, DNS basically works like a phonebook. When you wants to find a number, you don't look up the number first, you look up the name first then it would give you the number.
So to break this down into further details:
Let's examine the step that DNS takes. So when you type in facebook.com in your web address and if your web browser or operating system can't find the IP address in its own cache memory, it would send the query to the next level to what is called the resolver server - the resolver server is basically your ISP (Internet Service Provider) so when the ISP receives the query, it will check its own cache memory to find an IP address for facebook.com and if it can't find it, it will send the query to the next level which is the root server. The root servers are the top or the root of the DNS hierarchy.
There are 13 sets of this root servers and they are strategically placed around the world and they are operated by 12 different organizations and each set of this root servers has their own unique IP address. So when the root server receives the query for the IP address for facebook.com, the root server is not going to know what the IP address is but the root server does knows where to send the ISP to help it find the IP address. So, the root server will direct the ISP to the TLD (Top Level Domain) server for the .com domain. So, the ISP will now ask the TLD server for the IP address for facebook.com. The Top level domain server stores the address information for top level domains such as .com, .net, .org and so on.
This particular TLD server manages the .com domain which facebook.com is a part of, so when a TLD server receives a query for the IP address for facebook.com, the TLD server is not going to know what the IP address is for facbook.com. So, the TLD will direct the ISP to the next and final level which are the authoritative Name servers.
So once again, the ISP will now ask the authoritative Name servers for the IP address for facebook.com. The authoritative name servers or servers are responsible for knowing everything about the domains which include the IP address. They are the final authority, so when the authoritative name server receives the query from the ISP, the name server will respond with the IP address for facebook.com. And finally, the ISP will tell your computer the IP address for facebook.com and then your computer can then retrieve the Facebook web page.
It is important to know that once the ISP receives the IP address, it will store it in its cache memory in case it receives another query for facebook.com so it doesn't have to go through all those steps again.
While the process seems complex and believe me it is, this whole cycle take less time than it takes you to blink an eye.
DNS was designed to work extremely fast and efficient. It is an integral part of the internet. Once you understand this, you can clearly see the many different facets and organizations that are responsible for a single DNS lookup. One Look-up!
There is a resolving name server, the root name server, the TLD name servers , and authoritative name servers. If anyone were to dramatically change or filter any part of the DNS process, it could lead to disaster.
This is why we believe the people with the power to pass legislation need to understand what's at stake before making decisions that could drastically affect how the internet works.
