"ComputerNetworking"
Heyy guyz...😎
👉Introduction:
‣ To hack a device, one should know how they interact with each other. Two or more devices connected to each other form a network. Computer devices are connected to each other for purpose of file sharing, resource sharing, communication, etc. Devices in a computer network(communicating or networking devices) are called "nodes".
‣ Let's discuss some basic concepts related to networking...
👉Classification of Computer Networks:
⏩ Based on Geographical Coverage:
1. LAN
• It stands for Local Area Network. It can operable for an area covering an office, home network, a building. It is a small area network.
• A LAN network is a high speed, less in cost, and easy to manage.
• Examples: WiFi, LAN cable.
2. MAN
• It is known as Metropolitan Area Network. Its coverage area is several buildings, cities, or maybe a few states.
• MAN network has a large area than LAN, but less in speed and is more costly and hard to manage as compared to LAN.
• Example: CCTVs in the city.
3. WAN
• It is an acronym for Wide Area Network. The range of WAN is several countries and continents.
• WAN network is larger in area than LAN and WAN. But it has a higher cost.
• Examples: TV, the Internet.
⏩ Based on Accessibility:
1. Internal Network: Networks that are isolated from public access.
2. External Network: Publicly accessible networks(Internet).
IP Addressing and NAT
👉Client-Server Module:
‣ Server is a large computer that stores data and sends it when asked for. All website data is stored on a server assigned to that website.
‣ When you(client) type website name and hit ENTER, your device sends a request to the server and in response, the page is sent to your computer. This is called a Client-Server Module.
👉Data Packets:
‣ An image loads slowly in case of a slow internet connection because whenever you request image data, the server breaks it down into small chunks called "data packets" and then sends it to us, this makes communication efficient.
👉IP Address:
‣ When we connect to the internet, a unique number is automatically assigned to our device(computer). It's called an IP address. IP addresses are like Aadhar card numbers or home addresses of a network, they must be unique.
• Static IPs:
‣ These are IP addresses such that when we disconnect from the internet and connect again, our IP address remains the same.
• Dynamic IPs:
‣ When our IP address changes each time we connect to the internet are called dynamic IP addresses.
👉IP Address Versions:
1.IPv4:
‣ IPv4 is the fourth version of the internet protocol. It is one of the core protocols of standards-based internetworking methods on the internet. It is 32 bits long.
‣ Pattern of IPv4 is A.B.C.D where all A,B,C,D are numbers between 0 and 255.
‣ As using only IPv4 all the people cannot join a network(more than 4.2 billion), so IPv6 was introduced.
2.IPv6:
‣ IPv6 is the most recent version of the Internet protocol that provides an identification and location system for computer networks. IPv6 was created to dominate over the IPv4 address exhaustion.
‣ Pattern of IPv6 is A:B:C:D:E:F:G:H whereall A,B,C,D,E,F,G,H are hexadecimal numbers.
‣ Old devices don't support IPv6, so NAT is there. So, we deal with a combination of both IPv4 and IPv6.
👉IP Address Range:
• For small internal network(home or office) - 192.168.0.0 to 192.168.255.255
• For large internal network(MNCs or colleges) - 172.16.0.0 to 172.31.255.255
• For massive internal netw.(telecom. or satellites) - 10.0.0.0 to 10.255.255.255
‣ IP address 127.0.0.1 is called a loopback IP address or localhost of your local machine.
👉NAT(Network Address Translation):
• The process of transferring and translation of data between internal and external networks is called NAT. NAT does the work of IP address conservation.
• Basically, NAT allows a single device, such as a router, to act as an agent between the Internet (or public network with external IP) and a local network (or private network with internal IP), which means that only a single unique IP address is required to represent an entire group of computers to anything outside their network.
