Ethical Hacking Free Course: Episode-02; Everything about networking! (Basic 01)

Ethical Hacking Free Course: Episode-02; Everything about networking! (Basic 01)

Imagine if you were the only person in this world you would have to be tense about something? You had no fear of losing anything, no desire to gain anything, no greed, no lust, no instability. Always may be pleased with the Creator, so much to give you as a gift! If it weren't for the term "networking" in the computing world, many of today's modern computing tech would be unimaginable, such as the Internet! Problems start when many computers are connected at the same time, so bad people will try to break your security and security specialists will be very necessary. If it weren't for the term networking, you probably wouldn't hear today's hacking term. As you can see from the example above, there is so much competition, so much violence and hatred because there are so many people in the world at once.

Today is the second episode of this thematic hacking free course. In fact, when trying to publish a course, it is not a very difficult task, how to explain a topic to you — the difficult task is to explain a topic after a topic. In other words, you can say that indexing, and computing and hacking line indexing is a little difficult, if you have not done this before, no matter how expert you are, you need to get a little paragraph to sort things out! So that's what happened to me, so I couldn't decide which topic to start with, because in practice this topic is so vast that it's a little difficult to create a well-organized schedule.

Anyway, I'm going to start from scratch, and that's networking. But I will try to arrange the whole course a little differently. When I am discussing networking, this does not mean that I will only publish serial episodes on networking! Talking about networking, maybe we'll move on to WiFi, then maybe we'll move on to WiFi security testing, then we'll move on to a different term for networking, then maybe we'll move on to web server related topics. I will control the whole course in such a way that you never lose interest! Kenona Housei Vidya! So, hopefully you have a rough idea about the front episodes of the course! Now, without further ado, let's go straight into networking.

Computer network

When multiple computers start working together on the same protocol, it is simply a computer network. Whenever you try to connect one computer to another or talk, you must create a network. You also use Bluetooth to transfer files or songs from one phone to another while networking. So it's as simple as water to understand, networking is born by connecting multiple computers to the same network. But there are some profound things to note here. Think about it, when you are adding one computer to another, what more things are coming up here! First of all, the computer itself is a term, then how they are connected to each other. If connected by wire, then wireless network and if connected without wire,

Two computers may be able to easily connect to each other by making a direct connection, but if the number of computers is increased, then of course another third party device will be required, which will maintain all the connections. For example, you can easily connect one or two plugs directly to the wall socket, but if it is necessary to connect the TV, fridge, mobile, laptop charger, together, then multi-plug is required. In the case of networking  , routers, hubs, and switches  do just that.

This time, Bass connected the computers to one connection, but still technically no network will be created, until the computers start working on the same protocol, every computer must understand everyone's language. Suppose I speak Bengali and you say Chinese, then will communication between you and me ever be possible? Another piece of hardware that helps complete networking is the network card on your computer. In the past it needed to be installed separately, but now it is installed in a dedicated way with all computers.

IP address

Now suppose you put multiple computers together in one network, but how would a particular computer relate to a particular computer? Suppose you have connected 10 electric devices in a multi-plug, now if you provide current in it then each device will receive current equally. But if you want to supply a certain current to a certain electric device, then you must have an identity of the connected devices. The same is true of computer networks. An IP address is the virtual identity of a computer that makes it easy to locate any computer connected to the network.

IP addresses, usually "151.101.75.121" - are like this. But there may be different types of IP addresses and the number may change according to the type. So we will work according to the above reference. First we connected the computers together to the network and now we have the unique identity of all the computers, meaning that it will be possible to send special data or commands to any particular computer.

Now of course there are two different parts to networking. If you create a network by connecting the computers in your home or office together via wires or wirelessly, it will be called a local network. If you connect your local network to thousands of external local networks, it is called the Internet.  I will not say anything more about the internet here, I have already published the best article, you can read it. Local networks and the Internet work much the same way, but things are different. For example, when you are at home, you sit there yourself, because your house, right? Again when you are out, or in the office, there is another rule you have to follow, because the boss there is someone else.

IP type

The IP address I have described above is the IP version 4 - which has already expired. When you are connected to the Internet, of course, it does not mean that you are connected to millions of devices. But there must be a unique address, right? Bat version 4 is over long ago. We are filling the gap of this IP4 using one network address translation method.  There is a dedicated post about IP address , which is a must see!

As I said before, there are many types of IP addresses, and everyone's rules are different for networking. Private IP, Public IP, Static IP, and Dynamic IP. Private IP is the IP address used on your local network. As I said before, IP4 is over, but if you use an IP on a private network that has a separate or other device on another network, nothing will come of your network. Kenona own network, own 

Rules! 10.0.0.0  to  10.255.255.255  | 162.18.0.0  to  162.31.255.255  | And  192.18.0.0  to  192.18.255.255  পি IPs in this range are used as private IPs. Now the private IP of your computer may be "192.18.0.10" but this is not an Internet IP, it is your own IP. Now a public IP is required to be connected to the internet.

Public IP is the IP that the Internet service provider provides you. You turn on the computer, and connect to the Internet, what does that mean? This means you connected your Internet Service Provider's computer, and received a public IP from it. Dude, this is where Network Address Translation (NAT) comes in handy. Your router only accepts public IPs and hides private IPs from your local or home network. The router assigns a private IP to all connected devices, and when a request is made to the Internet from a computer, the router accepts the request and sends it to the public IP. The expectation from the public IP comes back to the request router, the router sends it to your computer's private IP, because the router knows very well, from which private IP the request came, And where to send it! Do you understand? This is how the internet has been kept alive using the net.

Dynamic IP | Static IP

Most public IP addresses change. This means that once you connect to the Internet, you are given a public address, but if you disconnect and reconnect, you are given another public IP, especially mobile operators. So if an IP changes, then it is called dynamic IP. Suppose you are not using the Internet, yet you do not need to keep that public IP, right? These ISPs give that IP to another customer. There is a lack of IP address, I understand!

However, if you want to host a website, then a static IP address will be required. If the IP keeps changing, no one will be able to communicate with your computer. And the websites are hosted on the computer just like your computer. Just as your home network is connected to a public IP to gain access to the Internet, so too is a server network to be connected to a public IP. You see, the issue is the same everywhere. If you want to receive courier service in your home regularly, then of course a specific and unchanging address will be required. If the address keeps changing, tell me how to find your home again and again?

DNS

Websites use domain names (such as sobuzbanglatv.blogspot.com) without using a direct IP, which is much easier to remember and has many advantages. But it is not possible to connect any computer without IP. So when you enter the domain name into the browser, the browser starts searching for DNS or the domain name server. The DNS contains that information, to which IP the domain is targeted, after which the site is loaded from just that IP. You  can learn more about this from The World Wide Web article.

The advantage of having a domain name is that it is easy to remember and the DNS can be changed. This means that if you transfer a site from one server to another, it means that the IP address is changed to the DNS of a site, there is no need to change the site name. The user cannot understand whether the server has been changed. But your ISP may be a little late to update the DNS record, so if the IP behind the domain is changed, the previous IP is removed from the record without getting that IP, so the site may be down. That is why after changing the sobuzbanglatv.blogspot.com server you may not be able to log in for some time.

Local Area Network (LAN)

Even though you have a good idea about LAN from the discussion above, it is still necessary to have a little discussion! As I said before, computers that are physically very close and connected to each other via wires are called LANs. Connections to the LAN can be made using an Ethernet cable, or WiFi, and routers, hubs, switches, etc. are required.

The devices on the LAN are directly connected to each other. Any device can make a connection with any device and send or receive data,   called a peer-to-peer network, to say how a  torrent  network works. But big networks like internet don't work like this, there is a web server  computer in the middle  , any request goes to the server first then the file / webpage goes to the client computer.

Now the question is, how big is it possible to build this local area network? সম্ভবIt is possible to create a local area network with thousands or millions of devices, starting from two devices, but even if you have millions of devices, it will not go to the Internet, for this you need to be connected to the rest of the world network. But you can call the local network of millions of devices your own internet.

Wide area networks and others

As I said before, there are many types of networks and each has a different role and importance, wide area network is one of them, you can call the Internet WAN (Wide Area Network). Here WAN refers to a computer network that is far away. Internet networks are spread all over the world. The network device connects the router, this LAN and WAN together. This means that when you connect to the Internet from a local network, it means you make a connection with WAN. But Wankeu can't be called a complete internet. Suppose you have created a bank network, each bank has a local network and the bank branches are spread in different parts of the city, now if you connect all the local networks, in this case technically one will be created. But how long can it not be called the Internet, As long as you connect to this van with a connection from an ISP. So you can say, ISP provides internet connection on any LAN or WAN.

There are several other types of networks, such as;

1. WLAN  - Wireless Local Area Network
2. MAN  - Metropolitan Area Network
3. SAN  - Storage Area Network, System Area Network, Server Area Network, or sometimes Small Area Network
4. CAN  - Campus Area Network, Controller Area Network, or sometimes Cluster Area Network
5. PAN  - Personal Area Network

Wireless local area networks are  largely dependent on WiFi or separate wireless technology, the LAN that will connect to WiFi can be called W LAN. The metropolitan area network  can be spread out in different places, it is bigger than LAN but smaller than WAN. Database or storage using fiber channel technology If special computers are connected to the network, it is called  SAN  or  storage area network  . Cluster area networks  can be created by connecting large and high-config computers together  .

So this was the second part of the Basic Part 01 course on everything about networking. I am finishing today's course here, because I have dragged out a long time, maybe you already knew a lot of this information, but it is still good to practice once. Networking Part 02 will show some practical issues. For example, finding the IP of the following network card, finding the local IP, using the DNS tool and detailed and practical discussion, we will see how to make a static IP from dynamic IP, MAC address is also detailed in the front part! So stay tuned for the second part of the Networking Part 02 course, I hope you will learn something fun there! Let me know in the comments below what the course of this episode looked like. If you have any questions, please note below! So many thanks so far today for reading this post to the end.

Hope everybody on this site also had a great day.  Stay  well, stay healthy, stay safe with Sobuz  Bangla  TV . Thanks. God bless you.  

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