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Networking 1 - Basics

What is a network? is the first question comes in mind when you want to learn about networking.
So a network is connection (it can be wired or wireless) between devices.

The connection needs some structure means how devices will be connected so here cones the Topology.
in this we need wires (cables) for wired connections and access points for wireless connection. we do not make connection from only one device to another, there are lots of devices so to make proper connection we need network devices like switch, routers.

Lets talk a bit about cables - Straight cable and Cross cable.
Straight cable is used to connect dissimilar devices like switch to pc. And Cross cable is used to connect similar devices like pc to pc or switch to switch.

For making any connection we need addresses so in networking we are having 3 types of addresses

1.MAC address - (48 bits) It is hardware address and given by manufacturer.
2.IP address - (32 bits IPv4) You can say it is logical address or software address.
3.Port address - (16 bits) where the application runs.

To explain MAC and IP and Port address I would like to take an example of House address - so the house no is the MAC address and the way to reach house is IP address and gate were you will enter and perform your work is Port address.

Now before going to Topology I will discuss about Hub, Bridge, Switch.

Hub - Just look at the image I made to Hub you will understand how it is working, we can call it multi port repeater. If you send a message from one PC so Hub sends that message to all the PCs expect the one from where it came from so its broadcast but the problem was if two or more PCs are sending at the same time so it will create collision . Here we need Bridge


Bridge - so Hub is not having property to understand physical or logical things it was just broadcasting. Now what bridge is doing it stops the signal when it goes from one HUB to another by understanding the logical and physical properties. You can understand it with Image.

Switch - there was still problem when two PCs are sending message from one domain at the same time.
so Switch came to stop single collision domain with the help of MAC table you can call it Hub+bridge.

Note - Devices in Different layers.
           Network layer - Router 
           Data Like layer - Bridge, Switch
           Physical - Hub, Repeater 
Topology and After that OSI Model in Next Blog

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