Computer networking – Basics

Basics of Computer Networking

Networking is when one or more computers are connected through wires or wireless devices to share some information / files between them. Here let me explain you few basic things about the computer networks and the devices that are used in the process of networking.

Basics of Computer Networking

Basics of Computer Networking

The computers can be broadly classified into two types. They are:

  1. Open system
  2. Closed system

Open System:

Any computer that is connected to any kind of network (inter or intra) and is ready to communicate is known as the open system.

Closed System:

Any computer that is not connected to any kind of network and is not communicable from any other computers is known as a closed system.

Also the networking types can be classified into two different types.

  1. Internet
  2. Intranet

Internet:

When the computer is connected to a global network of computer system and has the capacity to communicate around the world, then it is said that the computer is connected to an internet.

Intranet:

The computer is said to be connected to intranet when it is connected with the local area network specially designed for the computers within the office premises or the school premises.

Some of the devices that are used in the networking of computers are as follows.

  1. Routers
  2. Network Switch
  3. Network Hub
  4. Bridge

Routers:

Routers are the devices that are capable of forwarding the network data packets between two or more computer networks. They send / receive the data packets from the other routers. They are responsible for data transfer between the networks.

Network Switch:

Network switches / Switches are present in the 2nd layer (data link layer) and it uses the MAC addresses to forward the data.

Network Hub:

Network hub act as a connection point between the devices in the network. It contains many ports and each segment of the LAN is connected to a port. When a data is received at one port of the hub then it gets copied to all the other ports so that it can be seen by all the other hosts of the other network.

Bridge:

The bridge is a device that helps multiple networks to form a single network. It connects multiple networks to form a single network. The main difference between router and bridge is that routers allow multiple networks to communicate with each other and stay as different network. But the bridge combines them into a single network.

Some of the other devices that belong to networking,

Access Points:

Access points are the devices that helps the devices to get connected to the wireless network. It is very useful in the wireless communication.

Also when it comes to networking we need to understand how the networking is done between the computers. Based on the type of layout of the network they are categorised. These categories are known as topologies. Some of the most used topologies are listed below.

  1. Point to point
  2. Star
  3. Ring
  4. Daisy chain
  5. Mesh
  6. Tree
  7. Hybrid

There may be other topologies available but these are the most used ones in the networking. You can learn more about them here.

When you are ready to learn networking you need to know some of the key terms that are used in the networking field. Some of them are given below.

IP Address / Logical Address:

It defines the network address of a computer or a device that is connected to any kind of the network. These are some numbers that are unique to each devices that are connected to the international network. You can simply classify the IP address into two types:

  1. Private IP Address
  2. Public IP Address

Private IP Address:

Private IP address is given to a computer in the local area network and it can be used to identify the computer in the local area network. These addresses can’t be used in the wide area network.

Public IP Address:

When a computer is connected to a wide area network then surely it will be assigned a public IP address. The computer can be addressed by any computer around the world.

How to find IP Address of a computer / device? – Read more.

MAC Address:

MAC (Media Access Control Address) is known as the physical address and it is unique to each device. It is assigned using the Network Interface Card.

Port:

In networking you will hear this term often. It denotes the channel through which the data packet is sent and received by the application. Every application has it’s own port. The range of ports exists between the numbers 0-65535

Socket:

Socket number is just a combination of both IP address and the port number. When you want to mention an application that is running in a particular server then you can denote it by writing the IP address with socket number. Example: 127.0.0.1:5354

ARP (Address Resolution Protocol):

Data link layer in the network uses the ARP to convert the IP address to the MAC Address so that it can know the MAC address of the computer that sent the data packets using the received IP address.

RARP (Reverse Address Resolution Protocol):

This means finding the IP address of the device that sent the data packets using the MAC address received. Just the reverse of ARP.

Host:

A host is any computer / device that acts either as server or client in the internet. It will be called as peer if it acts both as server and client.

Firewall:

Firewall is an application that keeps the unwanted network network traffic from reaching the private network. Also when you connect your system with the open internet you must have your firewall ready to monitor both the incoming and outgoing traffic. Mostly all the major router brands will have firewalls installed in their routers.

Let’s now get to know how these networks are classified into different categories. There 3 main classification and two normal classification.

  1. LANs
  2. MANs
  3. WANs
  4. SANs
  5. VPNs

LAN – Local Area Network

When some computers that are present inside an office building, schools, colleges are connected together to form a network then those networks are known as the local area networks.

MAN – Metropolitan Area Network

When two or more LANs across two different places are connected together to form a network then those networks are known as MANs.

WAN – Wide Area Network

Simply this is called internet. Internet is a wide area network where a computer or a device is connected to all other computers in the internet.

SAN – Storage Area Network

These types of connections are made between the storage devices so as to provide the high speed data transfer between the computers and storage devices.

VPN – Virtual Private Network

Most of you might already be heard of VPNs. VPNs are used primarily used to send data very securely across the internet. Mostly people around the world uses the VPNs to access the blocked content in their country.

One more terminology that you need to know is the client and server difference:

Server:

Any computer that holds the data or webpage that can be served to multiple computers / hosts upon request is known as server. For example every website you see on the internet is hosted on some kind of server. Upon request from any of the client or host machines these servers provide the content to the client machines.

Client:

Any computer that receives the data from any of the server is known as client computer. It may be any device that requests data from the server it will be known as client. Also a system can act both as client and server.

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