DEV Community: Israh Binoj

Understanding Switch learning & Collision Domains (Lab notes) | Israh Binoj

Israh Binoj — Wed, 26 Nov 2025 15:47:51 +0000

What Is a Switch?

A switch is a network device used to connect multiple devices within the same network and transfer data packets between them. It operates at Layer 2 of the OSI model, meaning it deals with MAC addresses and Ethernet frames. Unlike hubs, which broadcast data to every connected port, a switch sends data only to the specific port where the destination device is located. Because of this selective forwarding, switches are more efficient, reduce unnecessary traffic, and make the network much faster.

The main function of a switch is the forwarding of frames. When it receives an Ethernet frame on one port, it forwards it only to the port where the destination device is connected.

Frame Filtering

A switch also filters frames. This means it blocks frames from being sent to ports where the destination device does not exist. This prevents unnecessary broadcasting and improves overall network performance.

To do this, switches build a MAC address table, also known as a CAM table (Content Addressable Memory). This table stores the MAC addresses that the switch has learned along with the ports they are connected to. With this information, the switch knows exactly where to send future frames.

Frames and MAC Addresses

An Ethernet frame contains several fields, including:

Source MAC address

Destination MAC address

Ethertype

Payload

Switches use the source MAC address of incoming frames to learn where devices are located. They use the destination MAC address to decide where to forward the frame.

MAC Address Table (CAM Table)

The CAM table stores MAC addresses and their corresponding ports. There are two main types of entries:

Dynamic entries: Learned automatically when the switch sees a source MAC on a port

Static entries: Manually configured by the network administrator

How Switches Learn MAC Addresses

A frame arrives on a port.
The switch reads the source MAC address from the Ethernet header.
It records the source MAC in the MAC table along with the port number.
If the destination MAC is not present in the table, the switch floods the frame out of all other ports.
When the destination device replies, the switch learns the destination’s MAC address from that reply.
From then on, frames are forwarded directly to the correct port without flooding.

Collision Domains

A collision domain is a set of interfaces on a shared medium where two devices can transmit at the same time, causing their frames to collide. Collisions are a major problem in hub-based networks.

With switches, every port becomes a separate collision domain, especially when operating in full-duplex mode. Modern switches almost always use full duplex, which allows devices to send and receive data at the same time, effectively eliminating collisions.

How Switches Reduce Collisions and Provide Better Bandwidth

Switches greatly reduce collisions for several reasons:

Port isolation: Each switch port is its own collision domain.

Selective forwarding: Only the required frames are sent to the correct destination port.

Support for full-duplex communication: Devices can transmit and receive simultaneously, avoiding collisions entirely.

These features allow switches to provide dedicated bandwidth to each connected device, making networks more reliable and faster.

Practice: Observing Switch MAC Learning Using Packet Tracer

Step 1: Create a Small LAN

First, I created a simple LAN using Cisco Packet Tracer.
The network includes one switch and five PCs.

Each PC is connected to a separate switch port using Copper Straight-Through cables.

PC0 -> Switch port Fa0/1

PC1 -> Switch port Fa0/2

PC2 -> Switch port Fa0/3

PC3 -> Switch port Fa0/4

PC4 -> Switch port Fa0/5

This cable type is used to connect end devices (PCs) to a switch.

Step 2: Assign IP Addresses to the PCs

Next, I assigned IP addresses to each PC so that they can communicate.

To set the IP:

Click the PC

Go to Desktop -> IP Configuration

Choose Static and enter the IPv4 address

I used the following addressing:

PC0: 192.168.1.2

PC1: 192.168.1.3

PC2: 192.168.1.4

PC3: 192.168.1.5

PC4: 192.168.1.6

The Subnet Mask is automatically set to 255.255.255.0 for all PCs.

Step 3: Generate Traffic Using Ping

To allow the switch to learn the MAC addresses, I generated network traffic between the PCs using the ping command.

For example, on PC0:

Go to Desktop -> Command Prompt

Enter:

ping 192.168.1.3

Then I repeated the ping command to other PCs (PC2, PC3, PC4).
This traffic allows the switch to learn the source MAC addresses of each device.

Step 4: Check the Switch’s MAC Address Table

Finally, I checked whether the switch successfully learned the MAC addresses.

Click the Switch

Go to the CLI tab

Press Enter

Type:

enable

and then,

show mac address-table

The output shows the MAC address table, where the switch has stored each PC’s MAC address along with the port number it was learned from.

This confirms that MAC learning occurred successfully.

Lab is successfully completed and u learned how MAC address table stores the addresses.

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Understanding Hubs In Networking| Israh Binoj

Israh Binoj — Tue, 25 Nov 2025 17:45:52 +0000

A hub is one of the simplest networking devices used to connect multiple devices in a small network. It acts as a central point where data from one device is received and then forwarded to all other connected devices without checking where the data actually needs to go. This simplicity makes hubs easy to use, but also limits their efficiency.

Types of Hubs

Active Hub

An active hub works with its own power supply.
It regenerates and amplifies incoming signals before forwarding them, which helps maintain signal strength over long distances.
Because of this, active hubs are used in larger setups or long-distance networks and function similarly to repeaters.

Passive Hub

A passive hub has no power supply of its own.
It simply splits the connection and sends the signal as it is, without boosting or strengthening it.
This type of hub is suitable for very small networks where the distance between devices is short.

Smart (Intelligent) Hub

A smart hub, also known as an intelligent hub, includes basic management features.
It can monitor network traffic, detect errors, and provide limited network diagnostics.
Although not as advanced as switches, it offers more functionality than basic hubs.

Hub in the OSI Model

Hubs operate at Layer 1: The Physical Layer of the OSI model.
They do not understand MAC addresses or make any forwarding decisions.
Their job is simply to send whatever they receive to all ports.

Number of Ports

Most hubs are available with:

4 ports

8 ports

16 ports

These ports allow you to connect multiple devices within a simple local network.

Why Hubs Are Not Used in Modern Networks

Hubs create one large collision domain.
When multiple devices send data at the same time, collisions occur, causing the network to slow down significantly.
As more devices are added, collisions increase and performance decreases.

Because of this inefficiency, hubs have largely been replaced by switches, which handle traffic much more intelligently.

Half-Duplex Communication

Hubs only support half-duplex mode, meaning:

A device can either send or receive data,

But not both at the same time.

This further slows down communication, especially in busy networks.
In contrast, switches support full-duplex, allowing sending and receiving simultaneously.

How Hubs Transmit Data

Bit-by-Bit Transmission

Hubs forward data one bit at a time in the form of electrical signals.

No Address Filtering

Hubs do not read MAC addresses.
They cannot direct data to a specific device and instead broadcast everything to all connected devices.

Conclusion

Hubs are simple devices ideal for small or temporary networks, but their limitations are collisions, half-duplex mode, and lack of traffic control make them unsuitable for modern environments. This is why switches have become the standard choice for efficient networking.

Hubs in networking|Israh Binoj

Israh Binoj — Mon, 24 Nov 2025 18:07:28 +0000

A hub is one of the simplest and most basic networking devices used to connect multiple devices within a Local Area Network (LAN). It receives data from one connected device and forwards that data to all other devices on the network. The hub does not check which device the data is intended for, so every device receives the same information-even if only one device actually needs it.

In the OSI model, a hub operates at the Physical Layer (Layer 1). This means it does not understand MAC addresses, IP addresses, or any higher-level data. Its main job is just to repeat or broadcast electrical signals to every port. Because hubs have no intelligence or filtering capability, they simply forward everything they receive.

How a Hub Works

The working process of a hub is very straightforward:

A device sends data to the hub through one of its ports.
The hub does not inspect, analyze, or filter the incoming data.
It immediately forwards (broadcasts) the data to all other connected devices, regardless of the actual destination.
Out of all devices, only the intended device recognizes and accepts the data.
All other devices receive the same data, but they simply ignore it.

Because every packet is broadcast to everyone, hubs generate a lot of unnecessary network traffic. This also leads to more collisions, where two devices try to send data at the same time, causing interference. For this reason, hubs are far less efficient compared to switches, which send data only to the correct destination.

Uses of a Hub

Although they are not commonly used today, hubs still have several important uses:

Small Local Area Networks (LANs)

Hubs are used to connect multiple computers in small setups where traffic is low and simplicity is more important than speed.

Basic File Sharing

For simple file sharing or basic communication within a small group, a hub works well because of its plug-and-play nature.

Network Monitoring

Since hubs broadcast all data to everyone, they make it easy to monitor network traffic. Network administrators sometimes use hubs to capture packets for analysis.

Educational and Training Labs

Hubs are commonly used in computer networking labs to demonstrate how broadcasting, collisions, and basic network communication work.

Temporary or Low-Cost Networks

For short-term setups or environments with limited budgets, hubs offer a low-cost way to connect multiple devices without complex configuration.

Summary

A hub is a simple and inexpensive networking device that operates at the Physical Layer (Layer 1) of the OSI model. It connects multiple devices and broadcasts data to all of them without checking the destination. While this makes hubs easy to use, it also results in high traffic, frequent collisions, and lower efficiency compared to modern devices like switches.

Despite their limitations, hubs remain useful for learning, monitoring, and basic connectivity in small or temporary networks.

Network Interface Card- Detailed Notes|Israh Binoj

Israh Binoj — Sun, 23 Nov 2025 09:31:37 +0000

A Network Interface Card (NIC) is one of the most essential components in any computer or smart device. It allows the device to connect to a network either through a physical cable or wirelessly through Wi-Fi. A NIC is responsible for converting data into signals, handling communication, identifying the device using a MAC address, and ensuring reliable data transmission. Without a NIC, a device cannot access a LAN, the internet, or any other network.

Wired NIC

A wired NIC connects a computer to the network using an Ethernet cable. It contains an RJ-45 LAN port and converts digital data into electrical signals that travel through the cable. Wired NICs are known for their stability, low latency, and high-speed performance, making them ideal for desktops, servers, and gaming systems.

Types of Wired NIC

Onboard Ethernet: Integrated directly into the motherboard.

PCIe Wired NIC: Installed inside a desktop using PCIe slots and supports high speeds like 1 Gbps, 10 Gbps, and beyond.

USB-to-Ethernet Adapter: External NIC used for laptops or tablets that lack an Ethernet port.

Wireless NIC

A wireless NIC enables a device to connect to a network without any cables, typically via Wi-Fi. It uses radio waves to communicate with wireless routers, hotspots, and access points. Wireless NICs come with internal or external antennas to improve range and signal quality.

Types of Wireless NIC

Built-in Wi-Fi Card: Embedded inside laptops and phones.

USB Wi-Fi Adapter: Plug-and-play device for desktops and older laptops.

PCIe Wi-Fi Adapter: High-performance card with external antennas for desktops.

M.2 Wi-Fi Card: Slim and fast modules used in modern laptops.

Wi-Fi Standards

Wireless NICs support various Wi-Fi technologies such as:

802.11b (11 Mbps), 802.11g (54 Mbps)

802.11n (300 Mbps, dual-band)

802.11ac (1.3 Gbps)

802.11ax / Wi-Fi 6 (up to 10 Gbps)

802.11be / Wi-Fi 7 (30+ Gbps)

NIC in the OSI Model

A NIC mainly operates in two layers of the OSI model:

Layer 1 – Physical Layer: Converts data into electrical, optical, or radio signals.

Layer 2 – Data Link Layer: Handles MAC addressing, framing, and error detection.

Uses of NIC

NICs perform several important functions:

Connect devices to wired or wireless networks

Provide a unique MAC address

Convert data into signals

Manage data framing and packet transmission

Detect and handle errors

Support duplex communication and auto-negotiation of speed

NIC Speeds
Wired NIC Speeds

100 Mbps (Fast Ethernet)

1 Gbps (Gigabit Ethernet)

2.5 Gbps / 5 Gbps

10 Gbps Ethernet

25G / 40G / 100G for data centers

Wireless NIC Speeds

Depending on standards, speeds range from 11 Mbps (802.11b) to over 10 Gbps (Wi-Fi 6) and 30+ Gbps (Wi-Fi 7).

How a NIC Works

When a device sends data, the NIC receives it, adds the MAC address, creates frames, and converts the data into signals. These signals are then transmitted through cables or radio waves to the network. When receiving data, the NIC performs the reverse process: it checks for errors, converts signals back to digital form, and delivers the data to the operating system.

Components of a NIC

Controller Chip: The main processor of the NIC

Transceiver: Converts data to electrical or wireless signals

MAC Address ROM: Stores the permanent MAC address

Buffer Memory: Temporary storage for packets

RJ-45 Port: For wired NICs

Antenna: For wireless NICs

PCIe/USB Interface: Connects NIC to the motherboard

NIC Drivers

NIC drivers are software programs that let the operating system communicate with the NIC. They control speed, wireless security, power management, and packet handling. Without proper drivers, the NIC cannot function correctly.

NIC Slot Types

NICs can fit into different ports depending on the device:

PCI / PCIe slots (desktops)

Mini PCIe / M.2 slots (laptops)

USB ports (external adapters)

Virtual NIC (vNIC)

A virtual NIC is a software-based network card used inside virtual machines. It behaves like a physical NIC—receiving IP addresses, connecting to networks, and transferring data. vNICs are essential in cloud computing and virtualization.

NIC LED Indicators

Wired NIC ports usually have LED indicators:

Solid Green: Connection established

Blinking Light: Data activity

Amber/Yellow: High-speed connection (1 Gbps or more)

No Light: Cable unplugged or NIC disabled

Network Interface Card -NIC| Israh Binoj

Israh Binoj — Sat, 22 Nov 2025 09:55:46 +0000

A Network Interface Card (NIC) is an essential hardware component that enables a computer or any digital device to connect to a network. Without a NIC, a device would not be able to communicate with other devices, access the internet, or participate in any form of data exchange over a network. In simple words, NICs act as the bridge between a device and the network.

In our daily life, we often use different kinds of network adaptors, such as Wi-Fi dongles or Ethernet ports on laptops-these are all forms of NICs. Because of their purpose, they are also commonly known as LAN cards, Ethernet cards, or simply network adapters.

A NIC can provide either a physical connection using cables or a wireless connection using radio waves. No matter the type, the main job of the NIC remains the same, it manages all the data that enters or leaves the device through the network. It handles important tasks such as data packet formation, buffering (temporary storage of data), and error checking to ensure that the information is transmitted correctly.

How a NIC Works

The working process of a NIC can be understood in a few simple steps:

Data Conversion for Transmission
The computer generates digital data, but this data cannot travel directly through a cable or wireless signal. The NIC converts this digital data into electrical signals or radio signals. This conversion makes the data suitable for transmission through the network.
Transmission of Data
Once the data is converted, the NIC sends it out through the connected medium-Ethernet cable, Wi-Fi antenna, or fiber optic cable.
Receiving Data Signals
When data arrives from the network, the NIC receives those incoming signals. These signals could be electrical, optical, or wireless, depending on the type of NIC being used.
Converting Signals Back into Digital Data
The NIC then converts the received signals back into digital data so that the computer can understand and process it.
Addressing Using MAC Address
Every NIC comes with a unique MAC (Media Access Control) address. This hardware address ensures that the data reaches the correct device, just like a home address ensures correct delivery of mail. The MAC address helps identify the source and destination devices within a local network.

Types of NIC We Commonly Use

NICs come in different forms based on the type of connection they provide:

Wired NIC-Ethernet

This is the most common type found in desktop computers and some laptops. It uses an RJ-45 Ethernet port and provides a stable and high-speed wired connection. Wired NICs are preferred in offices, gaming setups, and places that require reliable, uninterrupted connectivity.

Wireless NIC - Wi-Fi Adapter

This type of NIC allows devices to connect to Wi-Fi networks using radio signals. Most smartphones, tablets, and modern laptops come with built-in wireless NICs. External USB Wi-Fi adapters are also available for devices that do not have built-in Wi-Fi.

USB NIC

These are portable plug-and-play adapters that can be connected through a USB port. They can offer either Ethernet or Wi-Fi connectivity and are commonly used when the built-in NIC is damaged or unavailable.

Fiber NIC

Used in high-speed and enterprise networks, fiber NICs support extremely fast data transfer through fiber optic cables. They are commonly used in servers, data centers, and advanced networking environments.

Conclusion:

A Network Interface Card may look simple, but it plays a crucial role in enabling communication between devices. Whether we are browsing the internet, streaming videos, or transferring files, the NIC silently manages all the behind-the-scenes data handling, ensuring smooth and efficient network connectivity

Creating a Physical Wired Network in Cisco Packet Tracer - My Experience | Israh Binoj

Israh Binoj — Wed, 19 Nov 2025 08:45:22 +0000

In this article, I am going to explain how I created a physical wired network in Cisco Packet Tracer and the difficulties I faced during the process.

1. Downloading Cisco Packet Tracer

The first step was to download Cisco Packet Tracer from the link provided by Udemy.
After the download completed, I installed it just like any other regular application.

2. Creating a Cisco Account

Before using Packet Tracer, I needed a Cisco account.
I created the account, verified my email, and saved my login credentials for future use.

3. Logging Into Cisco Networking Academy

After launching Packet Tracer for the first time, the application asked me to log in.
I signed in through Skills For All by Cisco, which provides access for three months.
Once I logged in successfully, Packet Tracer opened and I was ready to begin my project.

4. Creating a Basic Physical Wired Network

The first task I attempted was to create a simple wired physical network.
My network consisted of:

One PC

One Switch

One Copper Straight-Through cable

This is the basic structure of most small networks.

Steps I followed:

Step 1: Adding a PC

I selected a PC from the End Devices section and dragged it onto the workspace.

Step 2: Adding a Switch

Then I selected a 2960 series switch from the Switches category and placed it on the workspace.

Step 3: Connecting the Devices

To connect the PC and the switch:

I clicked on the Connections (lightning bolt icon).
I chose the Copper Straight-Through cable.
I clicked on the PC and selected FastEthernet0.
Then I clicked on the switch and selected FastEthernet0/1.

The connection line turned green, which indicated that the cable was working and the link was active.

5. Difficulties I Faced

While creating the network, I faced a few difficulties:

At first, I was confused between the Logical and Physical workspace views. I assumed that choosing the Physical view was necessary to create a wired network, but I later learned that all wired networks are created in the Logical view.

I had trouble finding the correct cable type because there are many options, such as cross-over, console, and fiber cables.

The link did not turn green immediately, which made me think the cable was not connected properly. It took a moment for the device to power on.

This simple network was my first step in understanding how devices communicate in a wired environment.

Wired Network Topology in detail | Israh Binoj

Israh Binoj — Tue, 11 Nov 2025 13:08:16 +0000

Why is a star topology more reliable than a bus topology, even though it needs more cables?

In a star topology, every computer is connected to a central device like a switch or hub.
If one cable or computer stops working, it doesn’t affect the rest of the network ,only that single connection fails.
But in a bus topology, all computers are connected through one main cable.
If that cable breaks or has a problem, the entire network stops working.
That’s why a star topology is more reliable even though it uses more wires.

In a ring topology, how does data know when to stop at the right computer?
In a ring topology, data travels in one direction around the circle.
Each computer checks if the data is meant for it.
If the address doesn’t match, it passes the data to the next computer.
When the right computer gets the data, it accepts it and stops passing it on.
This way, the message always reaches the correct device.

How can a logical topology differ from the physical wiring of a network in real life?

The physical topology shows how the devices are actually connected with cables.
The logical topology shows how the data moves between them.
For example, a network may be wired physically like a star (all computers connected to a switch),
but the data may flow in a straight line, like in a bus topology.
So, the way the network looks and the way data travels can be different.

Why does a mesh topology provide better fault tolerance compared to other topologies?

In a mesh topology, every computer is connected to all the other computers.
This gives multiple paths for data to travel.
If one cable fails, the data can still reach its destination through another route.
Because of this, mesh topology is very reliable, though it needs more cables and costs more to set up.

Why is bus topology considered outdated in modern wired networks, even though it’s cheap and simple?

Bus topology was used in older networks because it was easy to install and required only one main cable.
But it has many problems , when too many computers send data at the same time, the data can collide.
If the main cable gets damaged, the whole network stops working.
It’s also slow when more computers are added.
That’s why star or hybrid topologies are used more today.

Can a hybrid topology have both wired and wireless parts? How does it work together?

Yes, it can have both.
For example, in an office, some computers may be connected with cables in a star shape, while laptops and phones connect through Wi-Fi.
Both the wired and wireless parts can communicate with each other using the same network.
This makes hybrid topology more flexible and suitable for modern use.

What kind of cables are usually used in wired topologies and why are they preferred?

Most wired networks use Ethernet cables like Cat5e or Cat6.
They are preferred because they are fast, reliable, and can transfer data without much loss.
In bigger or faster networks, fiber optic cables are used.
They carry data as light signals, which makes them faster and better for long distances.

How the data collision occur in a bus topology, and how do modern systems avoid it?

In a bus topology, all computers share the same cable.
If two computers send data at the same time, the signals crash into each other, this is called a data collision.
When this happens, both computers have to resend their data, which slows the network.
Modern systems avoid this by using switches and special methods like CSMA/CD that check if the line is free before sending data.

In a mesh topology with 5 computers, how many direct wired connections will be required between them for a full connection?

In a full mesh topology, each computer is directly connected to every other computer.
To find the total number of connections, we use the formula n(n − 1) / 2.
Here, n = 5, so 5(5 − 1) / 2 = 10 connections in total.
That means every computer will have 4 separate cables connecting it to the other 4 computers.

So, here we explained wired network topology in detail with some questions... Stay tuned!

Wired Network Topology|Israh Binoj

Israh Binoj — Sun, 09 Nov 2025 06:59:10 +0000

Wired network topology refers to the physical or logical connection of devices such as computers, switches, or routers in a wired network, meaning they are connected using physical cables.
It defines how data is transmitted between devices and how each component interacts within the network.
Different types of wired topologies, such as star, ring, and mesh, offer varying levels of performance, reliability, and scalability.

Wired Star Topology

A wired star topology is created by connecting all devices to a central device, usually a switch. Each computer or device has its own dedicated connection to this central device — this is how a star topology works.

It is easy to install and manage, and it also provides high performance. When a device sends data, the hub or switch receives it and then forwards the data either to the intended recipient device only (in the case of a switch) or to all devices (in the case of a hub).

This topology is commonly used in office LANs, school or college computer labs, and home networks.

Wired Ring Topology

In a wired ring topology, each device is connected in a circular manner, forming a closed loop. This loop allows data to flow in a single direction until it reaches its destination.

It allows orderly transmission of data and provides good performance. In this topology, every device gets an equal chance to transmit data.

In a dual ring topology, two rings are used to connect all devices. Each device is connected to its neighboring devices through two separate cables, allowing data to be transmitted in two directions.

Data usually travels through the primary loop, but if that loop fails, the secondary loop starts transmitting the data. This provides redundancy and fault tolerance.

It is commonly used in Metropolitan Area Networks (MANs) and industrial networks that require high reliability.

Wired Mesh Topology

A wired mesh topology is a type of network layout where every device is connected to every other device in the network through dedicated physical cables. This creates multiple paths for data to travel, ensuring high reliability and fault tolerance.

There are two main types of mesh topology:

Full Mesh: Every device is connected to all other devices.

Partial Mesh: Some devices are connected to all others, while others connect only to a few.

In a wired mesh topology, data can take multiple routes to reach the destination device or server. Each device in the network acts as both a sender and a receiver, helping to transmit data across the network efficiently and reliably.

Network Topology|Physical and Logical Topology and types in detail| Israh Binoj

Israh Binoj — Thu, 06 Nov 2025 14:56:46 +0000

What happens if the main cable in bus topology fails?

In a bus topology, if the main cable fails, the entire network stops working.
This happens because all the devices are connected to a single main cable, which acts as the backbone of the network. If this cable fails, the whole system fails, and data cannot reach its destination or the server.

How movement in ring topology occurs in one direction?
In a ring topology, data moves in a single direction ,either clockwise or counterclockwise.
Each device is connected to two other devices, forming a closed loop.
Each device receives the data, checks if it is the intended recipient, and if not, forwards it to the next device in the loop.
This continuous flow of data around the ring is how a ring topology works.

How mesh topology enables data transmission?

In a mesh topology, each node is connected to every other device in the network, creating multiple paths for data transmission.
Here, every device has a direct connection to all other devices, so if one device needs to send data to another, it can do so directly without passing through any other device.
Since there are multiple paths, if one path fails, the data can use an alternate route, ensuring effective and reliable networking.

How multiple topolgies connects in hybrid topology?

A hybrid topology is a combination of two or more different types of network topologies, such as ring, star, and mesh.
Data transmission in a hybrid topology depends on the type of network topology used in each part of the system.
For example, if a star topology is used, data first passes through the central hub or switch.
If a bus topology is used, data travels through the main cable.
In this way, data transmission in a hybrid topology follows the rules of the specific topologies that make it up.

How does a hybrid topology combine the advantages of different topologies?

In a hybrid topology, two or more network topologies are combined together. While implementing this, the hybrid topology takes the strengths of each individual topology and uses them to improve network performance. It does not include or use the weaknesses of any topology in the hybrid design.

What determines whether a network follows a particular type of topology?

This is an important concept. For example, consider two types of logical topologies - logical ring and logical star.

In a logical star, data passes through a central device such as a hub or switch.
In a logical ring, data passes from one device to another in a loop until it reaches its destination.

The choice of topology is completely based on the data flow pattern and communication method, which determine whether the network behaves as a logical ring or a logical star — regardless of the physical structure.

Widely used topology and why?

The most commonly used network topology is the Star Topology.
In a star topology, all devices are connected to a central device such as a hub, switch, or router.

Features that make it commonly used:

Easy to install and manage
High performance
Scalable (easy to add new devices)
Managed through a central server or device

Commonly used in:

Wi-Fi router setups
LAN (Local Area Network) configurations
Offices, schools, and home networks.

Least used network topology and why?

The least commonly used or not widely used network topology is the Mesh Topology.
In a mesh topology, every device is connected to every other device in the network.
While this provides high reliability and fault tolerance, it is very expensive and complex to set up and maintain.

Can a network have a physical star topology and a logical star topology together?

A network can have a physical star topology and a logical star topology together.
In this setup, physically, all devices are connected to a central device like a switch or router.
Logically, data also passes through that same central device, which controls communication between all devices.
So both the structure and the data flow follow a star pattern ,meaning the network has a physical star and logical star topology at the same time.

Which is the most affordable network topology to set up?

The most affordable network topology is the Bus Topology.
In this topology, all devices share a single main cable, called the backbone. It uses less cabling, requires no central device, and is cheaper and easier to install than other topologies.
It is mainly used in small and simple networks.
Bus topology needs minimum cabling, with no need for switches, hubs, or routers, making it easy to set up ,and that’s why it is considered affordable.

Network Topology| Israh Binoj

Israh Binoj — Mon, 03 Nov 2025 04:46:26 +0000

Network topology means the arrangement of a computer network in a geometric structure. It defines how computer networking devices communicate effectively with each other. It shows the arrangement of nodes and links, such as devices and connections. It also describes how the connections work - whether physically or logically.

There are two main types of network topology:

Physical Topology: The physical arrangement of devices and cables.
Logical Topology: The path that data follows within a network.

Physical Topology
It is the physical appearance of how a network looks - the actual layout of cables, switches, computers, and other devices.
It shows the physical connections between devices using wires, fiber optics, or wireless links.
In simple words, it is the outline or map of how a network is physically arranged.

Operates in the physical layer
Purpose: To install and design the physical network

Types of Physical Topology

Bus Topology:
All devices share one main cable.
Star Topology:
All devices connect to a central hub or switch.
Ring Topology:
Devices form a circle; data moves in one direction.
Mesh Topology:
Every device connects to every other device.
Tree Topology:
Star networks joined in a tree shape.
Hybrid Topology:
Mix of two or more topologies.

Logical Topology

Logical topology explains how data actually flows through a network. More than the physical layout, it focuses on the working and communication of the network. It defines the path of data packets and how they move between devices.
Data may travel in a different pattern than the physical connections, so logical topology shows the actual flow of data within the network.

Operates in the data link or network layer
Purpose : To understand and control how data moves.

Types of Logical Topology

Logical Bus:
All devices share the same communication line.
Logical Ring:
Data travels in one direction around a loop.
Logical Star:
Data passes through a central device like a hub or switch.
Logical Mesh:
Data can take many paths to reach its destination.

Conclusion

Physical topology shows how a network looks, and logical topology shows how it works. Both together make a network clear, connected, and complete.

Purpose of computer network and more | Israh Binoj

Israh Binoj — Thu, 30 Oct 2025 17:53:04 +0000

Purpose of computer network protocols

Computer network protocols are sets of rules that define how data is transmitted and communicated over a network. They ensure that data is exchanged efficiently, accurately, and securely between computers and devices.

Physical protocol

A physical protocol defines the actual physical rules for data transmission, including cable type, voltage levels, and signal timing.
Examples: Ethernet, Wi-Fi, USB.

Logical protocol

A logical protocol defines the software-based rules for communication between devices. It manages addressing, routing, error detection, and data formatting.
Examples: IP, TCP, UDP, HTTP, HTTPS, FTP.

OSI model and layers

The OSI (Open Systems Interconnection) model is a framework that standardizes how data is transmitted across networks. It has seven layers, each with specific functions for data communication - from physical transmission to user applications.

Functions of the Presentation Layer in the OSI model?

The Presentation Layer (Layer 6) translates data between the application and the network. It handles encryption, compression, and data format conversion to ensure compatibility between systems.

Role of the Transport Layer in the OSI model?

The Transport Layer (Layer 4) ensures reliable data transfer between devices. It manages error detection, flow control, and segmentation of data.
Examples: TCP, UDP.

Four layers of the TCP/IP model?

The TCP/IP model has four layers:

Application Layer - Provides services for applications (web, email).
Transport Layer - Ensures reliable transmission of data.
Internet Layer - Handles routing and addressing of data packets.
Network Access Layer - Manages physical transmission over hardware.

Main types of IP addresses?

Answer:

Public IP - Identifies a device on the internet.
Private IP -Used within a local network.
Static IP - Fixed address that doesn’t change.
Dynamic IP -Assigned automatically and may change over time.

Difference between Half Duplex and Full Duplex communication

Half Duplex: Communication occurs in both directions but only one device can send data at a time.

Full Duplex: Both devices can send and receive data simultaneously.

Ethernet and uses

Ethernet is a networking technology used to connect devices in a Local Area Network (LAN) using wired connections. It provides high-speed, stable, and secure communication between computers, routers, and switches.
Examples: Fast Ethernet, Gigabit Ethernet.

How Computer network works | Israh Binoj

Israh Binoj — Tue, 28 Oct 2025 17:19:15 +0000

Computer Network Protocol

Computer network protocols are the standard rules that define how data is transmitted and communicated over a network. They ensure that information is exchanged efficiently, accurately, and securely between computers and other devices. Every network follows these rules to enable effective communication.

Two types of network protocols

1) A physical protocol defines the actual physical rules for the transmission of data over a network. It specifies details such as the type of cables, voltage levels, signal timing, and data transmission rates. Examples of physical protocols include Ethernet, Wi-Fi, and USB.

2) A logical protocol defines the rules and procedures for logical communication between devices. It manages the software structure of data transmission rather than the physical structure. The key functions of a logical protocol are addressing and routing, error detection, flow control, and data formatting. Examples include IP, TCP, UDP, HTTP, HTTPS, and FTP.

OSI model

The OSI model is a framework that defines how data is transmitted through a network and how communication occurs between different devices. It divides the process of networking into seven layers, which helps organize and standardize communication across various systems and technologies. Each layer has a specific function that contributes to the successful transmission of data.

The 7 Layers of the OSI Model

Application Layer (Layer 7)
This is the topmost layer that provides network services directly to users and applications. It enables activities like web browsing, email, and file transfer.
Examples: HTTP, HTTPS, FTP, SMTP, DNS
Presentation Layer (Layer 6)
This layer translates data between the application and the network. It handles data encryption, compression, and format conversion to ensure compatibility between systems.
Examples: SSL, TLS, JPEG, MPEG
Session Layer (Layer 5)
The session layer manages sessions or connections between two devices. It establishes, maintains, and terminates communication sessions.
Examples: NetBIOS, PPTP, RPC
Transport Layer (Layer 4)
This layer ensures reliable data transfer between devices. It handles error detection, flow control, and data segmentation.
Examples: TCP, UDP
Network Layer (Layer 3)
The network layer is responsible for logical addressing and routing of data packets so they can travel across different networks to reach the destination.
Examples: IP, ICMP, IPsec, Routers
Data Link Layer (Layer 2)
This layer ensures reliable communication between devices on the same network. It handles framing, physical addressing (MAC), and error detection.
Examples: Ethernet, PPP, Switches
Physical Layer (Layer 1)
The physical layer deals with the actual transmission of raw data bits over a physical medium, such as cables, switches, and radio signals. It defines hardware specifications like voltage, data rate, and cable type.
Examples: Ethernet cables, Wi-Fi, Bluetooth, Hubs

TCP/IP model

The TCP/IP model is a framework that is also known as the simplified version of the OSI model. It focuses on practical data communication over the internet. The model consists of four layers, each performing different functions, and they all work together to make network communication efficient and reliable.

The 4 Layers of the TCP/IP Model

Application Layer: Provides services for applications such as email, file transfer, and web browsing.
Transport Layer: Ensures the reliable transmission of data between devices.
Internet Layer: Handles the routing of data packets and manages logical addressing.
Network Access Layer: Manages the physical transmission of data over hardware like cables and network interfaces.

IP Address
An IP address is a unique number assigned to every device connected to the internet that uses the Internet Protocol for communication. It acts as an identifier for a device and ensures that the data sent reaches the correct destination.

There are four main types of IP addresses:

Public IP: Used to identify a device on the internet.

Private IP: Used within a local or internal network.

Static IP: A fixed address that does not change.

Dynamic IP: Assigned automatically and may change over time.

Duplex communication

Duplex communication refers to the way data is transmitted between two devices. It defines whether communication happens in one direction or in both directions.

Half Duplex: Two-way communication, but only one device can send data at a time.

Full Duplex: Two-way communication that allows both devices to send and receive data simultaneously.

Ethernet

Ethernet is a technology used to connect computers and other devices in a Local Area Network (LAN). It defines how data is transmitted over a wired network between devices such as computers, routers, and switches.

Ethernet provides high-speed, stable, and secure data transmission, allowing multiple devices to communicate efficiently within a local area.

Examples: Ethernet, Fast Ethernet, Gigabit Ethernet, etc.