Brief Understanding Of Domain Name System, IP & MAC Address

I hope you have read my previous article which was about how data is sent from one computer to another.
So every person has an identity by using which other people can identify him.

MAC Address

So in case of computers/mobiles when a computer is manufactured, they are given a serial number kind of thing to their Network Adapter or NIC (Network Interface Card) called MAC Address. A MAC Address looks like this 00:A0:C9:24:C3:

IP Address

But when a device (mobile/computer) is connected to the internet then MAC Address can’t be used to identify it. It gets a new identity called IP address. Didn’t get it?
When we have to send and receive something from a person who is far away, we need his address, right?
Well in case of internet an address is called an IP Address. and here is how an IP Address looks like
But it looks too weird for an address right? It looks familiar to a phone number and the human brain is bad at memorizing meaningless things for long.

Domain Name System(DNS)

So someone developed a system called the Domain Name System. DNS is like a phone book, like a phone book store numbers with respect to names, so we do not have to memories all those digits.
A DNS does exactly the same, it assigns a name called Domain to every IP address. A domain looks like or etc.
So whenever we want to go to a website, we enter its domain, and then DNS changes it in a computer-readable address (IP Address).
Let me explain this process in detail with a graphic

So I want to visit and I entered its domain in my browser so what happens behind the scenes is:
1. Your PC then asks your DNS server (Your ISP’s DNS server or some custom server) for the IP address of the server hosting the domain you want to go to.

2. Your ISP’s DNS server checks the root DNS servers to find out which servers know about the domain you want to visit.

3. Your ISP’s DNS server then asks that DNS server for the domain you want IP information of. When it receives the information its stores the information for future use (and this process is called caching) and then returns it to your PC.
Your browser connects to this IP address and asks for a web page.

Your computer then stores the domain name and its respective IP address so it does not have to look it up in DNS Server. The cache of this information is called DNS Cache and hackers can use it to perform an attack called DNS Cache Poisoning.

We will read about that later, for now, I hope you are understanding the basics properly.
Also Read: A Beginner’s Guide To Ports


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