What is NETWORK SWITCH? [CONCEPTS] [In Depth Explanation]

In this article, we will learn about Switch in a computer network.


But first, let’s jump for basics⚡

=>  A network switch has many ports and we can connect different computers to different ports.

⚡So the switch is used to communicate between these connected computers.⚡

switch basically remembers that which port is connected to which MAC Address


(MAC Address:- Everyone should be knowing it!👀

But still

its a physical address of a device (it’s not a network property)

And every device has it! Doesn’t matter if the device is connected to a network or not!

Now as you guys know…

Our main aim is to go to the in-depth working and cleaning the concepts…

Let’s dive in🙂



Now the main thing is to study


Now the main point to be noted is that the switch will never add itself the mac address of the devices connected to its ports

instead, it will keep on adding it as the data flow starts…..

To understand it better let’s take a real-life example

⚡A Switch has its own LOOK UP table

(in this table switch stores all the mac address of computers which are connected to its corresponding ports!) 🙂

Now talking about the LOOKUP table…

That’s how it looks like…⚡

Currently, the table is empty…  And you will soon understand why🙂

We will understand the concept with a real life flowing example

So at the very beginning, we have connected a few computers to a switch

now we power up the switch…⚡⚡⚡

⚡Now at the very beginning, the LOOKUP table of the switch is empty!

(there is nothing stored in it and in fact, the switch will itself not try to fill it up.It will not write it down itself that which port is connected to which MAC address.👀

What it will do is just wait…………….. it will keep on waiting until)

Until any connected devices try to send something to any other connected device🙂

Now a realistic example to replicate whatever will go on now……..

Computer 1, 2, 3, 4 are connected to the switch

Computer 1 wants to send some data to computer 3


So comp.1   will prepare an ethernet frame (people who are new to networking can consider it a simple data packet)

Ethernet frame basically consists of

 MAC address of the sender

MAC address of the computer to whom it is sending data

The data which is being sent


so what happens is ….. switch takes the Ethernet frame.




Now a very important term is to be introduced


But still, it doesn’t know to whom the packet needs to be sent because the receiver’s port and receivers mac address is not updated in the look-up table

So switch sends that data to all the connected devices

This is known as FLOODING

now as the data was for comp.3……… comp.3 will send a response for it to comp.1


Now in this response, the comp.3 will prepare its ethernet frame and sends to the switch


Now from that Ethernet frame the switch will again update its lookup table and adds the port and mac address of  comp.3

But in this case, the network switch knows that the data is being sent to comp.1

and to which port is comp.1 connected

as it is already present in the look-up table

so this time the data will directly go to comp.1

And this process will not undergo any flooding  🙂

💎 That’s the working of a Switch in computer network guys!💎

Read it carefully⚡

Understand the working⚡

If you have any Doubs, Queries, Confusion regarding this concept… Or article or any images shown.

Do ask!

Never build up misconceptions🙂💛


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