What is Network Hub? - Scaler Topics

Overview

A hub in a computer network is a basic networking device that connects multiple devices in a local area network (LAN). Unlike more advanced devices like switches or routers, hubs in computer network operate at the physical layer and simply broadcast incoming data to all connected devices, regardless of the intended recipient. This can lead to inefficient network traffic management and potential security risks. As a result, hubs have become largely obsolete in modern networking setups, replaced by more intelligent and efficient devices.

What is the Hub?

A hub in computer network, is a foundational device used to connect multiple computers or other network-enabled devices within a local area network (LAN). It operates at the physical layer of the OSI (Open Systems Interconnection) model, which is responsible for the actual transmission and reception of data over the network medium, such as Ethernet cables.

The primary function of a hub incomputer networkis to amplify and broadcast incoming data signals to all devices connected to it. When a hub receives data from one device, it replicates that data and sends it to all other devices connected to the hub. This broadcasting method, often referred to as "flooding," does not take into account the intended recipient of the data. Consequently, all connected devices receive all transmitted data, regardless of whether it's relevant to them.

Types of Hub in Computer Network

Hubs in computer network are devices used to interconnect multiple devices within a local area network (LAN). They operate at the physical layer of the OSI model and are responsible for transmitting data signals between devices. There are several types of hubs in computer network, each with its own characteristics and capabilities. Here, we'll explore three main types of hubs in computer network: Active Hub, Passive Hub, and Intelligent Hub.

Active Hub

An active hub is a type of hub that not only serves as a point of connection for multiple devices but also actively regenerates and amplifies the data signals it receives before transmitting them to connected devices. Active hubs are sometimes referred to as "multiport repeaters" due to this signal regeneration function. They have built-in power supplies that allow them to boost the strength of weak signals, ensuring that data reaches all connected devices without degradation.

Passive Hub

A passive hub, also known as an unpowered hub or a dumb hub, is a more basic form of hub that lacks the signal regeneration capabilities of an active hub. It serves as a central point for connecting devices but doesn't amplify or regenerate data signals. Instead, it relies on the devices themselves to ensure that signals are strong enough to be transmitted and received. Passive hubs don't require their own power supply, which makes them simpler and cheaper than active hubs.

Intelligent Hub

An intelligent hub, also known as a smart hub, is an advanced version of a hub that incorporates some features typically found in switches. While it still operates at the physical layer and broadcasts data to all connected devices, an intelligent hub can identify the source address of incoming data frames. This allows the hub to maintain an internal table that maps MAC addresses (device's unique identifier on a network, helping direct data to specific devices by using a set of hexadecimal digits for recognition and routing) to specific ports. When a data frame is received, the intelligent hub checks its internal table to determine which port the data should be forwarded to, reducing unnecessary broadcast traffic.

How Does a Network Hub Work?

A hub in acomputer networkoperates at the physical layer of the OSI model and serves as a basic device for connecting multiple devices within a local area network (LAN). Its primary function is to transmit data signals from one device to all other devices connected to the hub.

As network demands increased, hubs in computer network were replaced by more advanced devices. Switches, for instance, operate at the data link layer (Layer 2) and use MAC addresses to intelligently forward data only to the specific device it's intended for. This significantly improves network efficiency by reducing unnecessary traffic. Routers, operating at the network layer (Layer 3), go further by facilitating communication between different networks and providing more advanced traffic management capabilities.

Features of Hub

Signal Amplification: Hubs in computer network amplify weak incoming data signals to ensure they can be transmitted to all connected devices without degradation.
Broadcasting: Hubs in computer network broadcast incoming data to all devices connected to their ports, regardless of the intended recipient.
Physical Layer Device: Hubs in computer network operate at the physical layer (Layer 1) of the OSI model, handling the basic transmission and reception of data signals.
Multiple Ports: Hubs in computer network typically come with multiple ports (ranging from a few to several ports) to accommodate several devices in a network.
Simple Setup: Hubs in computer network have a straightforward setup process, requiring minimal configuration. Devices can be easily connected using standard Ethernet cables.
Cost-Effective: Hubs in computer network are often more affordable than more advanced networking devices like switches or routers, making them suitable for basic networking setups.
Legacy Systems: Hubs might still be used in legacy systems or specific scenarios where more advanced devices are not available or necessary.

Applications of Hub

Legacy Systems: Hubs in computer network serve as bridges between older and newer devices, enabling communication in legacy network setups.
Temporary Networks: Hubs in computer network are employed in short-term or event-based networks, offering basic connectivity without complex configurations.
Education: Hubs in computer network are utilized in educational environments to teach networking fundamentals due to their simplicity.
Basic Data Collection: Hubs in computer network play a role in basic data collection scenarios, providing insights into overall communication patterns.
Low-Budget Solutions: Hubs in computer network are chosen for cost-effective networking solutions where advanced features are not necessary.
Troubleshooting: Hubs in computer network serve as basic diagnostic tools, allowing administrators to monitor network traffic for troubleshooting purposes.
Laboratory Experiments: Controlled laboratory settings use hubs for straightforward networking in experiments without requiring advanced features.
Very Small-Scale Networks: Hubs find application in very small networks like home setups where advanced networking capabilities are unnecessary.
Compatibility Bridges: Hubs facilitate communication between older and newer devices, bridging compatibility gaps in mixed network environments.

Advantages of Hub

Simplicity: Hubs have a straightforward setup and require minimal configuration, making them suitable for basic networking needs.
Cost-Effective: Hubs are generally more affordable than switches or routers, making them a budget-friendly choice for simple setups.
Legacy Compatibility: Hubs can bridge the gap between older and newer devices in legacy systems, enabling communication.
Educational Use: Hubs serve as valuable tools for teaching networking concepts in educational settings due to their basic functionality.
Basic Data Collection: In scenarios requiring simple data collection, hubs provide a way to monitor overall communication patterns.
Temporary Networks: For short-term setups or events needing quick connectivity, hubs offer an easy way to connect devices.
Low Latency: Hubs introduce minimal latency due to their basic data forwarding, making them suitable for latency-sensitive applications.
Backup or Redundancy: In situations requiring backup connectivity, hubs can provide a basic failover solution.
Limited Isolation: In certain scenarios, hubs can help isolate devices, although data security is compromised as data is broadcast to all.

Disadvantages of Hub

Broadcasting Traffic: Hubs broadcast incoming data to all connected devices, causing network congestion and inefficiency.
Security Risks: Due to broadcasting, hubs lack data security as sensitive information is accessible to all devices on the network.
Collision Domain: Hubs create a single collision domain, leading to data collisions, network slowdown, and performance degradation.
MAC Address Limitations: Hubs cannot differentiate between MAC addresses, leading to unnecessary data processing by devices.
Performance Impact: As the number of devices increases, hub performance degrades due to increased collisions and data flooding.
No Quality of Service (QoS): Hubs lack support for Quality of Service features, impacting the performance of real-time applications.
Incompatibility with Modern Technologies: Hubs lack compatibility with modern networking technologies and protocols.
Limited Scalability: Hubs are not suitable for large networks due to inefficiencies and collision issues.
Obsolete Technology: Hubs have become outdated with the emergence of more advanced networking devices like switches and routers.
Small-Scale Networks: Hubs are suitable for small-scale networks where efficiency and advanced traffic management are not critical requirements.

Difference between Hub and Switch

Aspect	Hub	Switch
Operation	Operates at the physical layer, broadcasting data to all connected devices.	Operates at the data link layer, selectively forwarding data based on MAC addresses.
Traffic Handling	Broadcasts incoming data to all devices on all ports.	Forwards data only to the intended recipient device based on MAC address.
Network Efficiency	Inefficient due to broadcasting, leading to network congestion and reduced bandwidth.	More efficient, as data is only sent to the specific device that needs it.
Collision Domain	Creates a single collision domain, leading to more collisions and data loss.	Creates separate collision domains for each port, reducing collisions and improving performance.
Security	Lack of security as data is accessible to all connected devices.	Enhanced security as data is directed only to the intended recipient device.
MAC Address Learning	Does not learn MAC addresses or maintain a MAC address table.	Learns MAC addresses and maintains a table for efficient data forwarding.
Scalability	Not suitable for large networks due to inefficiency and collisions.	Suitable for large networks as they can handle more devices without performance degradation.
Management	Limited management capabilities, basic network connectivity.	Offers advanced management features like VLANs, QoS, and port mirroring.
Network Segmentation	Cannot segment networks or isolate devices effectively.	Allows network segmentation and isolation using VLANs.
Cost	Less expensive due to simpler functionality.	More expensive due to advanced features and capabilities.
Modern Network Usage	Obsolete in modern networks due to limitations.	Commonly used in modern networks for efficient data handling.

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Conclusion

Hub Basics: Hubs are elemental devices operating at the physical layer, facilitating basic connections within a local area network (LAN). They amplify and broadcast data signals to all connected devices.
Switch Sophistication: Switches transcend hubs with their data link layer operation. Their ability to selectively forward data based on unique MAC addresses enhances network efficiency and reduces unnecessary traffic.
Security Implications: Hubs' indiscriminate broadcasting poses security risks as sensitive data reaches unintended recipients. Switches bolster security by forwarding data only to the intended device, safeguarding information.
Collision Management: Hubs foster collision domains, culminating in data collisions and network performance degradation. Switches institute separate collision domains for each port, mitigating collisions and bolstering network integrity.
Network Segmentation: The inherent limitation of hubs hampers network segmentation. Switches revolutionize this aspect by enabling efficient network isolation through Virtual LANs (VLANs).