Computer Networks

The term ‘Hacker’ first came into the world through MIT(Massachusetts Institute of Technology), when highly skilled professionals solved different problems using programming languages and came into existence in the year 1960s.

The first hacker’s conference took place in the year 1993 in Las Vegas, Nevada, and the conference was conducted by DEFCON. Every year in Las Vegas, Nevada, where government agents, security professionals, and black and white hat hackers from all over the world attend that conference, DEFCON is one of the most popular and largest hacker’s as well as a security consultant’s conferences.

In the late 70s, hackers and cyber criminals figured out how wired technologies work and how they could be used to gain additional advantage or misuse the technology. So in 1970, the field of hacking is concerned about hacking.

This is the beginning of the history of hackers.Now a days, hackers are evolving their hacking skills according to new technologies . Hackers primarily target small businesses, and a hacker attack occurs every 40 seconds.

Now let’s see how many types of hackers are there and which is one is the best to choose.

Ther are different types of hackers. We will try to understand the difference between them.


                White hat hackers are called ethical hackers. These types of hackers don’t have any bad intentions or harm organisation. They log into the system to test or evaluate its security measures, don’t have malicious intent, and are focused on helping the organisation improve its security measures.

It will be harder for a hacker to get into a system managed by a large company than it will be for a system operated by a small business. For that reason, it’s very important for online business to make sure it takes strong preventative measures by installing quality anti-malware security, spyware removal tools, and firewall software defense.

Black-hat hackers are mostly criminals because they use there hacking skills to harm organisation or steal data from small or big organisations. Black hat hackers may want to spy on staff and customers.

Their motives can vary from financial to political, or they can simply be showing off their skills. Since they know how serious the legal consequences are, these hackers do everything they can to remain anonymous.

 A grey - hat hacker is a security expert who may sometimes violate laws but usually does not have the malicious intent of a black - hat hacker.A “grey - hat hacker” is someone who does both black - hat and white - hat activities. They usually hack a system without the owner’s permission and it takes time to find vulnerabilities in it. They often ask for a price to fix the problem. This isn’t considered a crime, but it isn’t ethical either.

The term “grey - hat hacker” was first used in the late 1990s . It comes from the concepts of white hat hackers and black hat hackers. 

The James Bonds of the virtual world are red - hat hackers. They are not opposed to taking back what the cyber attackers stole from their victims.

A hacker wearing a red hat is trying to stop black hat hackers.Red - hat hackers do everything they can to stop the bad guys, including taking matters into their own hands. They have the capability to launch full- scale attacks to take down cyber attackers and destroy their resources.

There are two types of definitions for “blue - hat hacker”. Let’s explore both of them

 First, they are revenge seekers. These people don’t care about money or fame. They hack to take revenge against a person, employer, institution, or government. Blue - hat hackers use various cyber attacks on their enemies to cause harm to their data, websites, or devices.


Sometimes blue - hat hackers use various hacking techniques to gain unauthorised access to their targets’ email clients or social media profiles. They have the ability to send emails and post inappropriate messages from those profiles to take revenge.

 The second definitions is that they are outside security professionals. They are often invited to test the new software before it is released. Sometimes companies organise conferences for blue - hat hackers to find bugs in their online systems. Blue - hat hackers conduct various cyber - attacks test while causing no harm to the organization.

Green - hat hackers are the young people in the world of hacking. They are not aware of the security mechanisms and the inner working of the web, but they are keen learners and determined to elevate their position in the hacker community.

They don’t want to harm you. They may or may not be aware of the inner workings of the web. That’s why sometimes they can be harmful because they are not always aware of the consequences of their actions or how to fix them.

Government hackers are allowed to find vulnerabilities in electronic products to gain remote access to information of interest. Government investigators can use this information to monitor user activity and interfere with device operation.

The hackers are sponsored by the Nation/ state.

All the hackers have their own specific rules and regulations, except the black hat hackers.A person who is thinking of becoming the best hacker should choose to be an ethical hacker, i.e., a white hat. They basically don’t have any bad intentions towards harming the organization. There are numerous path to becoming an ethical hacker.

Below, we will see what the certification paths are to become an ethical hacker.

Certifications for learning Ethical hacking: 

A Person can choose any certification as per their interest.All the certification courses mentioned above are beginner to intermediate level certification to get entry into cyber security as an ethical hacker.

In this article we have seen all the types of hackers and heard the description of each hacker.Each and every hacker has their own different roles and responsibilities. Some of them wants to save the world, but some of them wants to give harm to organizations or individual people.

The journey of learning hacking is nice to take, and you can use these skills in the right ways. This will help every one to build a secure network organization.

How to turn your Firewall concepts from zero to hero

A firewall is one such solution that prevents unauthorised access to our computer systems and data. Now a days, protecting our sensitive data from unauthorised and unwanted sources is a major concern.   

We will discuss in this article the fundamentals of firewalls, such as their necessity, uses, drawbacks, and different types. Firewalls are mostly used by system administrators, system engineers, network engineers, and network administrators because they have to handle the configuration, troubleshooting, and monitoring of firewalls.

A firewall is a computer system or network component that allows authorised communications while preventing unauthorised access. Firewalls are still widely used and have had a significant effect on current security practises. 

Software, hardware, or a hybrid of the two can be used to implement firewalls. Unauthorized internet users are frequently prevented from accessing private networks linked to the internet by firewalls, particularly intranets. Every message entering or leaving the intranet must travel through the firewall, which inspects each one and rejects any that do not adhere to established security requirements.

A firewall system analyses network traffic using pre-established rules. Following that, it filters the traffic to stop any of that traffic from originating from unreliable or illegal sources. Only inbound traffic that has been set to accept is allowed. 

Firewalls utilise the following three methods to control traffic entering and exiting a network:

Packet filtering is one of the important services provided by firewalls. Packets are small data chunks that are inspected as they pass through the network using user-defined packet filtering rules.

Packets are permitted or denied based on a wide range of criteria:

A proxy server basically works as a middle-man for communication between devices. A Proxy server intercepts each message coming into and going out of the network. The true network addresses are effectively masked by the proxy server.

Proxy servers have long been used to store a local copy of the requested external data. This enhanced performance in circumstances with inadequate bandwidth by enabling clients to request data through the proxy rather than the real external source.

For the duration of the session, a “stateful” firewall stores key characteristics of each connection in a trusted information database. Monitoring TCP or UDP sessions between devices allows stateful packet inspection to provide services beyond simple packet filtering.

Stateful inspection allows for the tracking of connections coming from a trusted network. A state session table that stores this session information enables temporary firewall openings for return traffic that would otherwise be blocked.

To stop Denial of Service (DoS) attacks, connections from the untrusted network to the trusted network are carefully watched.

The client-server concept, which forms the basis for network security in modern computing, originated from firewalls. To examine traffic and reduce dangers, the majority of devices rely on firewalls or technologies that are quite similar to them.

Everyone thinks that firewalls are powerful enough to protect our computer systems or networks from online threats. However, “firewall is not very powerful”. Therefore, it’s crucial to employ additional defence mechanisms to assist in safeguarding the network and computer data. Cyber threats are dynamic in nature, a firewall should not be the only component considered while securing the home network.

Certifications play an important role for those who are already working as professional network engineers or with similar designations in networking domains. Several certifications are available on the market, but only a few provide the necessary skills and knowledge.

The Palo Alto and Fortinet Fortigate certifications are highly recommended for qualified Cisco engineers or professional network engineers. Both the certifications do not require any experience or certifications, but they recommend having basic knowledge of networking and cyber threats.

Core firewall principles like routing, VPN, user authentication, and firewall policies are covered by these certifications. Students will get knowledge about web filters and efficient application control to secure their users. 

Firewalls are an essential part of network security; anyone interested in learning about the setup and administration of firewalls, or those who are newbies in network security and want to advance their skill set, can choose this route.

So in this blog, we have provided an overview of firewall use, types, functions, and limitations. At Networkers Home, we provide both certifications and training for highly qualified Cisco engineers or individuals who want to learn and excel as professionals in firewall.

Why Networking Devices is the only skill you really need

According to each person’s area of interest, networking offers a large ocean of prospects that can lead to finally landing the dream jobs. A wide variety of gadgets are used in networking to start and aid effective fieldwork. In the field of networking, there are many different gadgets that all strive toward making this happen. Let’s now examine each of these gadgets closely to discover how they function and what purpose they serve.

In  networking, lots of devices are used to implement the networking topologies in organizations. Most of the important devices, such as hubs, switches, routers, bridges, gatways, and many more, will be discussed in this blog.

Networking skills will help students in most of the courses and also help them get started in IT domains. If a person starts their career in the developer domain, cyber security domain, or cloud computing domain, then students should have good command of the networking domain.

The Top Network Hardware Devices for Networking

A hub is a kind of networking device that connects several networking nodes by way of the physical layer. They are frequently used to connect computer in a LAN.

A hub contains a lot of ports. In order to connect to the network, a computer is connected into one of these ports. Data frames are broadcast to all ports when they arrive at a port, regardless of whether they are destined there or not.

It is a network device that lacks intelligence and broadcasts messages to all ports. It broadcasts messages basically. Half-duplex transmission is the mode. There is no software connected to them; they are passive devices. When multiple computers send data to the same port at once, collisions may happen during setup of the transmission.

In the OSI model, switches are networking components that operate at layer 2, or the data link layer. They establish connections between networked devices and employ packet switching to transmit, receive, either forward data packets or frames over the network.

Every data frames that enters one of the ports of a network switch is evaluated for its destination address, any necessary checks are performed, and the frame is then sent to the proper device. Broadcast, multicast, and unicast communications are all made possible.

The layer 3, or network layer, of the OSI model is where routers operate as networking devices. Receiving, analysing, and transmitting data packets between the connected computer networks is their responsibility.

Upon receiving a data packet, the router examines the destination address, check its routing databases to determine the best route, and then sends the packet along that same route. A routing table is present in routers and is periodically updated in response to network changes. 

It makes use of a routing protocol and checks the table to transmit data packets. In comparison to switches, hubs, bridges, and other networking equipment, routers are more expensive.

When two subnetworks that use different protocols need to be connected, bridges are used. It combines two LANs to create an extended LAN. All packets are accepted by a bridge, which then amplifies and transmits them to the other side. The bridges are clever devices that only permit specific packets from them to flow. A bridge only allows packets from one network node to another to pass through.

In the process of amplifying or regenerate a signals coming before retransmitting it, repeaters are network devices that operate at the physical layer of the OSI model.

Depending on the technology or the channel’s characteristics, an electrical signal delivered across a channel weakens. The signal is amplified by repeaters before being retransmitted. Even signals that have been distorted by transmission loss can be recreated by digital repeaters. Therefore, repeaters are frequently used to connect two LANs and create a big single LAN.

There are many different types of repeaters available, and each one serves a specific purpose in networking. Similarly to how different types of signals regenerate using different repeaters, different types of networks and LAN domains use different repeaters.

For signals to regenerate, two types of repeaters are used:

For the different types of networks that they connect, two types of repeaters are used:

For different LANs domains, they use two types of repeaters:

The digital data streams are transformed into analogue data signals via a modem. The signal between your phone connection and your computer is modulated and demodulated by the modem. Modulation and demodulation are hence abbreviated as “modem”.

When you try to upload data from your home computer to the internet, the modem receives the digital signal and converts it into an analogue signal that the phone network can use.

In a similar way, when computers request data from the internet, the modem receives the analogue data transmission over the phone and transforms it into a digital signal that the computer can use.

A gateway is a telecommunications network mode that joins two networks using various transmission protocols. A gateway acts as a network’s entry and exit points because all data must travel through it or connect with it before being forwarded.

A gateway is frequently described as being made up of a modem and a router. Regardless of whether data is transferred internally or outside, the gateway manages all network traffic. It is implemented at the network’s edge. When a network wants to communicate with another, the data packet is sent to the gateway, where it is then routed via the most efficient path to the desired location.

A Wireless LAN Controller (WLC) is a centrally located network device that the network administrator or network operations centre uses in conjunction with the Lightweight Access Point Protocol (LWAPP).

These network access points, often known as “fat” access points, are controlled, run, and configured separately. The WLC manages the wireless access point settings automatically.

Disadvantages of Wireless LAN Controller:

The Wireless Local Area Network (WLAN), which is frequently used in large offices and structures with enlarged business, is created by a Wireless Access Point (WAP).

The wired networks are linked to the wireless client by a wireless AP. Mobile users may access the network more easily, which boosts productivity and lower infrastructure costs.

A wireless access point (WAP) is a piece of hardware or a set-up LAN node that facilitates Bluetooth or Wi-Fi communication between wired networks and wirelessly enabled devices. Devices can connect to the internet or a network more easily thanks to WAPs’ radio transmitters and antennae.

A load balancer serves as the “traffic police” at the front of all servers, distributing client requests across all servers equipped to handle them in a way that maximises speed and capacity utilisation and makes sure that no server is overworked, which can result in performance degradation.

The load balancer routes traffic to the active servers in case one server goes offline. The load balancer initiates requests to a new server when it is added to the server group.

We discussed the most commonly used networking devices in any organisation in this blog. Also, lots of other devices are used in networking. If a candidate takes a CCNA or CCNP course, they will learn in depth. In this course, every networking device that is used is described, like the routing tables of routers, how classful addresses work, subnetting, and many more.

These abilities are useful in any IT field, whether the candidate is a developer, cloud engineer, or a cyber security analyst. Without a basic understanding of networking, candidates will not be able to understand any concept in depth. 

If a candidate wants to get a better salary, then they must have a basic understanding of networks. Best of luck!

Find out now, what should you do to grasp Linux fundamentals and core concepts

Linus Torvalds created the linux operating system as a research project at first. Computers all throughout the world utilise linux, an open source, free operating system. It’s particularly well-liked for use in servers.

Linux is supported by a wide range of hardware platforms, including Intel, AMD, Mac, Sun, Dec, Alpha. Linux is an important skill for Developer, Cyber security, Cloud computing, Networks engineer, etc.

For developers that require a dependable, stable platform with open source code, linux is a suitable option. However, linux file systems differ in structure from those available on Windows or MacOS, begineers to linux may find it challenging to get started. Additionally, whereas the majority of personal computers use graphical user interfaces, linux-based operating systems mainly rely on using the command line interface.

In this blog, we will see all the fundamental concepts of Linux and what skills and knowledge are required to master it. The following topics will be discussed in this blog:

Linux is different from any other operating system; each part of Linux is developed by different organizations. Various sections of linux include the kernel, shell tools, X server, system environment, graphical applications, and so on.

The popular linux distributions are Red hat enterprise, Debian, SUSE, Arch linux, and many more. Ubuntu, Linux mint, Raspbian, Kali, Backtrack all are debian based linux operating system. Red hat based linux operating systems such as, CentOS, Fedora core, Oracle linux, CERN, etc are mostly used.

SUSE is a worldwide open-source software firm with headquaters in Germany that creates and markets linux products to corporate clients. SuSE was founded in 1992, they have build lots of linux products and operating system such as, SUSE linux enterprise server, openSUSE, SUSE linux enterprise desktop.

Arch linux is an independently developed linux distribution, the Arch linux project was initiated by Judd Vinet in march 2002. Using Arch linux different types of linux operating systems are build such as BlackArch, Chakra, Arch linux 32, Arch linux ARM, etc.

A command line is an interface that accepts lines of text and transforms them into instructions for your computer. We can execute both simple and complex jobs through its terminal. We can perform some simple operations like adding, removing, and moving files. Additionally, we are capable of performing complex jobs including administrative chore (such as user management and package installation), networking operations (such as ssh connections), security tasks, etc.

Let’s check out 10 mostly used linux commands in our day-to-day life:

There are lots of other commands are also available such as less, whoami, tar, uname, In, grep, head, diff, cmp, sort, export, zip, unzip, ssh, service, traceroute, ifconfig, iwconfig, iptables, wget, and many more.

The linux file system is a group of data and/or files that are kept on a computer’s hard drive or storage. Your computer depends on this file system to identify the position and location of files in your storage; if it weren’t there, the files would act as though they were invisible, which would obviously result in a lot of issues.

In fact, there are a variety of file systems available for linux; the base of every linux file system is known as root and also denoted as a slash (/). 

The root directory contains of several file system such as: 

There are different types of linux file system are available, if you want to check what type of file system is mounted into your linux distro then you can use df -T command in terminal. Let’s check different types of file system are use in linux. 

There are other file system are also available such as Btrfs, vfat, tmpfs. 

A built-in text editor is included with every linux distribution. However, some editors include extra functions or a user-friendly interface. An application created for coding and editing in HTML, CSS, Javascript, PHP, and many other programming languages is referred to as a text editor, known as code editor.

The majority of editors have options for search and replace, easy navigation, syntax highlighting, and other features.

Let’s see different types of text editor available for linux user:

Lots of other editors are also present for linux user such as; Atom, Visual studio code, Notepadqq, Brackets, Bluefish, gVim, Neovim, Pico, Lime, Kate, and many more.

Shell scripting help to implement the process automation in linux. Nothing is more annoying than having to repeatedly type out lengthy commands. Shell scripts are straight forward text files that compile a list of shell commands into a useful “tool” that you can use rather than repeatedly putting them all in by hand.

The GNU Bourne-Again shell is the standard shell for many linux distribution (bash). The startup script used by the shell when it is first launched may be found in the .bashrc or .bash profile file and allows you to modify how the shell behaves.

A file containing a succession of the commands is called a bash script. The bash programme reads and processes these. The computer programme runs line by line.

Linux is a very important skill for those who are working or want to work in the cloud computing, networking, or cyber security domains. Because linux is mostly used in servers, anyone who wants to gain a thorough understanding of linux fundamentals and core concepts must master the skills listed above.

The most important part of linux skills is shell scripting; if anyone wants to master shell scripting, then learn all the topics inside the bash shell. It will help to automate daily tasks.

There are also some other skills one need to master, such as networking interface and configuration in Linux, the Boot Process in Linux, Native Linux Compilers, Software and Services, etc. When someone is taking a course like CCNA, CCNP, CEH, AWS or Azure, then they have to learn these concepts before learning their actual course. Furthermore, because linux is a lighter operating system than Windows or Mac, most professionals prefer to use Linux distributions.

Introduction to CCNA Networking devices, topologies, and Benefits of Networking

Networking is a vast domain, and Cisco provides an entry-level certification, the CCNA. But before enrolling for CCNA certification, a candidate must know the introduction to networking, which will help them understand the whole concept in an easy manner.

In this blog, we have covered the introduction of networking contents and tried to describe them in easy language, so a beginner can easily understand the networking concepts.

Networking helps solve the heavy work in an easy manner; it helps individuals as well as organizations. Let’s see a few of the best uses of networking below:

There are many different kinds of computer networks, ranging from a room-sized network of mobile devices (such as smartphones or tablets) connected via Wi-Fi or Bluetooth to the millions of computers dispersed throughout the world.

Computer networks are broadly categorised based on the geographic area covered and the data transfer rate as follows:

Only authorised users within the network have access to other computers or shared resources, making LANs relatively secure. Users can upload and download files to and from the local server, as well as print documents using a connected printer.

An expanded LAN known as a “metropolitan area network” covers a greater geographic region, such as a city or town. Although the data transfer rate in MAN can also be measured in Mbps, it is far lower than LAN. MANs can be extended up to 40 km, and they are sometimes formed by connecting many LANs.

A LAN could be joined to additional LANs by wired or wireless media to create a WAN. Through WAN, major corporations, institutions of higher learning, and governments link their various branches around the globe.

A few personal gadgets, including computers, laptops, smartphones, printers, etc., are connected to create the network. These gadgets are all located within roughly a 10-meter radius. Either a wired or wireless personal area network is possible.

Multiple devices, such as modems, hubs, switches, repeaters, routers, gateway, etc., are needed to configure networks with different capabilities and to transmit data over various transmission mediums.

A modem device is used for conversion between analog signals and digital bits. ‘Modulator Demodulator’ is the full form of modem. Modems are used to connect the source and destination nodes. At the sender’s end, the modem functions as a modular to turn the digital data into analog impulses. In order for the destination node to understand the digital data, the modem at the receiver’s end demodulates the analog inputs.

This Ethernet card is also known as a “Network Interface Card.” The network adapter is mainly mounted on the motherboard of a computer and used to connect to the internet through a wired network. 

Network cards are mostly controlled by software these days, as opposed to the days when we had to instal drivers for hardware devices.

A type of connector commonly used for Ethernet networking is the RJ45. It is a little wider than a phone jack, but otherwise similar. RJ45 stands for Registered Jack-45, and since each terminal of an Ethernet connection has an RJ45 connector, Ethernet cables are known as RJ45 cables.

A network device called an Ethernet hub is used to hook up various devices. Data received on one line is broadcast over the others. The disadvantage of using a hub is that data from two devices may collide if they arrive at the same time.

A bridge is utilised to divide a huge network into more manageable sections. The two separate network architectures or media types can be connected by a bridge, but the TCP/IP network layer protocols cannot. All segments must use the same network-layer protocols.

In a local Area Network, a switch is a networking equipment that is essential (LAN). A network switch is used to link several computers or communication devices together, much like a hub. When data is received, the switch takes the destination address out of the packet and checks a table to determine where to send it. As a result, it sends signals to only a few devices rather than all.

A router has more extensive capabilities than a hub or a switch since it can analyse the data being transmitted through a network, choose or modify how it is packed, and deliver it to a different type of network.

Whenever a router receives an incoming packet on one of its interfaces, it examines the packet’s destination address and then sends the packet to the interface that corresponds to the destination address based on that information.

The router keeps track of the networks that are linked in order to forward data packets to their destinations. The routing table is a database table where these records are kept. You can design routing tables either statically or dynamically.

All data entering or leaving a network must pass through a gateway in order to employ routing paths, which serve as the network’s entry and exit points. In addition to forwarding data packets, gateways also keep track of the host network’s internal connection paths and the known paths of other distant networks.

The topology of a network refers to how the computers and other devices are organized. The topologies of the mesh, ring, bus, star, and tree networks are popular.

In this topology, every device is connected to each other. Due to the simultaneous data transmission capabilities of several nodes, such a network can handle high traffic volumes.

⦁	Each node in a ring topology is connected to two new layers, one on each side. As a result, the nodes that connect to one another form a ring. A ring topology has a unidirectional link. Data can only be transferred in one direction as a result (clockwise or anti-clockwise).

Each communication device in a bus topology connects to a bus, which is a type of transmission medium. Data sent from a node is transferred to the bus and thereafter sent there in both directions. This implies that any node linked to the bus is capable of receiving data.


Each communication device is linked to a central node, which is a networking device like a switch or hub.Due to each device’s direct connection to the central device, start topology is thought to be particularly effective, efficient, and quick.

It is a hierarchical topology in which each branch may have one or more fundamental topologies, such as the star, ring, and bus. Such topologies are typically implemented in WANs that connect several LANs.

Candidates who earned the Cisco Certification CCNA have seen signigicant job advancement. This specific certification serves as the entry point to more difficult Cisco training materials and certificate programmes. 

Let’s check out the benefits of taking the CCNA networking course:

After clearing the CCNA certification, for many students, it becomes a game changer for them. Many of them got their first job in IT careers, and some of them got promotions in their respective fields.

Networking is the base of every IT domain, and those who want to build careers in the IT industry have to lay their foundations very carefully. Be sure you have the clear concept of networking before starting your career.

Computer Networks

Introduction to CCNA Networking devices, topologies, and Benefits of Networking

Find out now, what should you do to grasp Linux fundamentals and core concepts

Why Networking Devices is the only skill you really need

How to turn your Firewall concepts from zero to hero

How many types of Hackers are there?

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