DEV Community: MS

VLAN

MS — Tue, 16 Jan 2024 07:41:16 +0000

Introduction

First , No more wait I will be keep on posting content from now on . Lets start so in order to know about VLAN's we need to understand basics of the switch

Purpose of Switch and VLAN

Switches are placed between your router and devices for multiple uses but main purpose is for isolation between organizations and departments (just like subnetting but at an earlier stage) then within that comes our hero VLAN and its main purpose is.... same as switch and subnetting which is isolation . I know it might be confusing [ It will :) ]

WorkFlow

As you have seen , First step is the router then switch then comes our VLAN .Lets break it down with an example , Consider you have an office which has multiple departments and each department has multiple teams under it .

Office - Router
Department - switches
Teams - VLAN

Now you see why we need so much isolation , While doing R&D I had a doubt why use VLAN we can just add mutiple switches right ? No , Think about the space and cost and we are using VLANs to have separate broadcast domains under the same switch (same department has mutiple teams under it)

How do they communicate

Each VLAN has a tag (like an identity for it) . Consider a router which has two switches A & B and each switch has 2 VLANs ( Switch A - A1 , A2 ) and ( Switch B - B1 , B2 ).

If devices under a VLAN has to communicate , they can communicate directly as they are under same broadcast domain.(Like a team sitting in a same room can communicate directly)
If devices in VLAN A1 has to communicate with A2 then they send the MAC address of the device they wanna communicate to the switch (A) then the switch identifies that the MAC address specified in the packet belongs to it but different VLAN so it redirects to that VLAN and goes to the particular device
If devices in VLAN A1 wants to communicate with B1 or B2 ( different switch ) , Initially they will send the packet to the switch then the switch identifies it belongs to different switch and adds the VLAN Tag of A1 and sends to the router , the router checks the destination IP address in its routing table and check to which VLAN does it belong (In our case B1 ) so it adds B1's VLAN Tag and checks for the switch it belongs and forwards to it then the switch B check the VLAN Tag and forward to the specific VLAN and then to the device.

Conclusion

Its a hell of a topic and there are still much details to cover , I have just added what is it ? , How does it work and whats the purpose of it . If you have any doubts or clarification comment down below , I will be addressing it ASAP

Be Nice in comments :)

No Idea...

MS — Mon, 08 Jan 2024 11:44:43 +0000

Lets get right into the topic , i have no idea what to post next so if you guys have any concepts to get an idea on in security or networking . Kindly let me know in the comments so I can rip that topic off and make it easier to understand!!

IP Address

MS — Mon, 27 Nov 2023 07:43:07 +0000

Well here comes the major question in the entire IT industry , What is an IP Address and why do we need IP address , Who uses IP Address and much more..

Here I am who has done some R&D in this question and found something for you guys , So watch closely (read carefully)!!

Introduction

First this post is only gonna give an idea of what is IP address and how it works in real world so there is no theory part (definitions) and no indepth content to become the next network engineer the world has never seen. This post contains just info that every people need to know as IT employee or CS Student or who are all interested in this field

Lets Get Started

IP Address are assigned to your devices like lap , pc , mobile by your router.There were two types IPv4 and IPv6

IPv4 Address

Uses 32 bits addressing scheme so it has over 4 billion combinations which was not enough since we had more population than it (LOL :))
IPv4 addresses are typically expressed in dotted-decimal format (e.g., 192.168.0.1)

IPv6 Address

Uses 128 bits which had more combinations than IPv4
IPv6 addresses are typically expressed as eight groups of four hexadecimal digits, separated by colons (e.g., 2001:0db8:85a3:0000:0000:8a2e:0370:7334).

Among these we had separate types of IP address based on their usage

Public IP
Private IP
Static IP
Dynamic IP

And you may find much types in different sites. And these are 4 types based on day to day usage

Private IP

Lets start with private IP , then it will be easy for you to understand public IP after this.
This IP is provided by the DHCP in the router which has a few set of IP addresses in the pool (kind of storage) which will be assigned to your devices like laptop ,mobile,printer.
Using this private IP , they communicate with each other under same network if you wanna print a image from your mobile or lap just give print and if your printer is connected it just prints out right. This is because they are connected using their private IP address
All sharing data from PC to mobile applications works using the private IP's , Thats why it says to connect under same wifi network

Public IP

This address is given to the router by the ISP provider , so when you are using your laptop to search a youtube video which is in internet
When your laptop sends a request to the internet , the router uses a mechanism called Network Address Translation (NAT) to map your laptop's private IP address to the public IP address of the router.
So the internet ( outside your home network ) only knows your public address so when response gets back to the public IP ( which is router ) , the router has the mapping who asked youtube video and it finds with your private IP so okay this device asked so it sends back the response to your laptop

Static IP

From name we can identify that it never changes unless intentionally changed
For eg : Public IP which is assigned by your ISP to your router will never change unless you contact your ISP to change it for you , Even in some organization using LAN network when you connect and disconnect you always have same IP which means they configured that LAN to have static IP

Dynamic IP

Same as saw earlier in static , this one changes each time you connect to the network try it with your home network and you might see different IP address each time you connect to the internet
So how this works , As i said earlier there will be range of ip address available for router(DHCP) to assign so initially you connected to an IP (192.168.25.1) and disconnected , so that IP returns to available state in DHCP's pool and when you reconnect there might be few other available IP addresses too
So the router asks DHCP for available IP address and it picks the available address from the pool and sends back to router and from router to your device

And there raises a question , When i disconnect my older IP will it also be available in pool so is there a chance to get old IP itself ?
Ans : Yes , DHCP follows a lease functionality so when you disconnect and reconnect if the lease of that IP is not expired then it connects to the same device . And if the lease is expired and if it is not assigned to any other device and you may get the same IP based on just luck , There is no assurance here.

Conclusion

In simple words , IP addresses are names assigned to your devices. Lets end with a real world example , In your home you will be called by your nickname among your family and you communicate with each other using that But when you go outside of your home , your nickname doesn't work there so thats where your realname comes in play. And when you receive a courier to your home , The guy asks for your real name and your family understands that and gets you the package.
Now nickname - Private IP and Realname - Public IP , it strikes now right

And See you in next one :) and Be Nice in the comments and If you have any suggestions say it here

Subnetting

MS — Thu, 23 Nov 2023 11:09:24 +0000

Introduction

I see a lot of posts in dev but I haven't seen a clean one to explain about Subnetting , So why wait for others lets just jump on and created one myself.. ( And its pretty good Trust me )

Lets Get Started

Subnetting is a technique used in computer networking to divide a single, large network into smaller, more manageable sub-networks or subnets. Each subnet is identified by its own unique subnet address, allowing for efficient utilization of IP addresses and improving overall network performance and security (Thanks to ChatGPT for this one)

First when you check for the IP address in your terminal , You will see 3 addresses

IP Address
Subnet Mask
Broadcast

Lets say for an example we have an IP address : 192.168.241.9 and Subnet mask of 255.255.255.0 , Here 255 symbolizes that it doesn't change for other devices under the same network while 0 can be changed for other devices.

That is 192.168.241.2 , 192.168.241.245 exists while 192.168.24.56 doesn’t exist , From here you may got an idea of range for IP Address 192.168.241.0 -> 192.168.241.255 But here is a catch , Both the First address and last one are not assigned to any devices as their IP Because they have their own specific purpose

192.168.241.0 -> Network channel
192.168.241.255 -> Broadcast channel

Network Channel

The network address is like the label for the entire subnet.
It indicates the base address of the subnet. Devices within the subnet use the network address as a reference point to understand that they are part of the same network.
For example, if a computer is configured with the IP address 192.168.241.5 and another device is configured with 192.168.241.10, both devices recognize that they are in the same network because they share the common network address, 192.168.241.0.

Broadcast Channel

The broadcast address is used to send messages to all devices within the subnet. For instance, if a device sends a broadcast message to 192.168.241.255, all devices in the subnet will receive that message.

Why we need Subnetting

The key purpose is to organize IP addresses for better traffic control and security purpose
Consider you are maintaining a college with different
depts like science , maths , admin and much more. Without subnetting if science people want to share a specfic info to their science nerds when they use broadcast channel other depts will also be receiving the info and What if all the depts access the broadcast address simultanously , See this causes Traffic
Another scenario where one device is got hacked or corrupted then the entire network and all the devices in it will be affected
Now if we use subnetting , all have their separate own space (Isolation) so the traffic is less , if one device got affected only the devices in that subnet share the effect while other depts can calm and chill

Conclusion

In a simple way , When you have all your games , anime , movies and stuff under a same folder , That's pretty nasty right . Organize it and you are good to go! [Same stuff but for IP address and device communication]

See you again , Comment down how was it [ Be Nice :) ]