What is a Hub in Computer Networks and What is Its Purpose?

A hub in computer networks is a simple device that connects multiple computers or devices within a local area network (LAN). Its main purpose is to enable communication by forwarding data packets to all connected devices. Operating at the physical layer of the OSI model, a hub acts as a central connection point, making it easy to expand a network.

This article explains the meaning of network hubs, their function within computer networks, and how they operate. You will learn about the uses of hubs, their advantages and disadvantages, and discover the best hub devices currently available on the market.

Also, if you are interested in learning practical skills on hubs like their configuration and troubleshooting, enrolling in our online networking courses will help you master these skills.

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Function of a Hub

A hub primarily serves two essential functions:

1. Receiving Data: The hub collects data sent by connected devices.

2. Transmitting Data: The hub broadcasts that data to all other devices connected to it.

These functions are often labeled as Rx (Receive) and Tx (Transmit).

Since a hub can only send or receive data at one time, it operates in half-duplex mode, meaning it cannot perform both functions simultaneously. This is a primary reason why people prefer using switches, as they can transmit and receive data simultaneously, operating in full-duplex mode.

Read our article on Full-Duplex vs Half-Duplex

Key Features of a Network Hub

The following are the main features of Hub

● A hub transmits incoming data packets to all devices connected to it, regardless of the intended recipient.

● Hubs operate at the Physical Layer (Layer 1) of the OSI model, meaning they handle raw data signals without interpreting their content.

● Hubs support half-duplex communication, meaning data can only flow in one direction at a time.

● Hubs typically offer multiple ports (e.g., 4, 8, 16) for connecting devices, making them suitable for small networks.

Types of Hubs

There are three main types of hubs:

1. Passive hubs

Passive hubs are the simplest type of network hubs. They act as basic connection points, allowing data to pass through without any modification or amplification.

These hubs are typically used in star topology networks, where each device connects to a central point. However, because passive hubs do not boost signal strength, they do not improve network performance and are generally suitable only for small, low-traffic environments.

2. Active hubs

Active hubs go a step further by amplifying and regenerating the signals they receive before forwarding them to other devices.

This helps maintain signal integrity over longer distances and reduces the chances of data loss or corruption. Often referred to as multiport repeaters, active hubs may also include features like retiming, which ensures that signals are synchronized properly across the network.

3. Intelligent hubs

Intelligent hubs combine the signal-boosting capabilities of active hubs with advanced management features. These hubs can monitor network traffic, perform diagnostics, and even adjust data rates based on the needs of connected devices.

Intelligent hubs are typically used in larger or more complex networks where performance monitoring and control are essential for maintaining efficiency and security.

How Does a Network Hub Work?

A network hub acts as a central connection point for devices in a local area network (LAN). When one device sends data, the hub does not check the destination. Instead, it broadcasts the data to all connected devices, so every device receives the same information.

All devices share the same communication channel and bandwidth. If two devices send data at the same time, collisions occur, causing errors. When this happens, devices pause and retry after a random delay. Because bandwidth is shared, adding more devices reduces speed and overall network performance.

What is the 5-4-3 Rule in Hub Connectivity?

The 5-4-3 Rule is a guideline for networks that connect multiple hubs. This rule ensures reliable communication when multiple hubs are connected. It helps maintain signal integrity and avoid excessive delays or collisions.

According to the 5-4-3 rule, between any two devices on a network, there should be:

5 segments of cable (network links),

4 hubs connecting those segments,

And only 3 of those segments can carry active data.

Uses of Hub

● Home labs or classrooms.

● Legacy systems that require basic connectivity without advanced features

● Network monitoring, as hubs broadcast all data to every connected device, making it easier to capture traffic for analysis.

However, for most setups today, switches are preferred due to better performance and security.

Difference Between Network Hub, Switch, and Router

Let's compare hubs to switches and routers to understand where hub lacks in networking capabilities.

Advantages of a Network Hub

● Hubs are ideal for expanding an existing network by allowing more devices to be connected.

● With a hub, all connected devices can share data.

● A hub can simplify network management by centralizing the network's traffic.

● A hub is generally a more cost-effective solution than a switch or a router for small-scale networks.

● Hubs offer low latency, which is the time it takes for a signal to travel from one device to another. This makes them ideal for applications that require real-time data transfer, such as video streaming or teleconferencing.

Disadvantages of a Network Hub

● Hubs broadcast data to all connected devices, which can lead to excessive traffic and slow down the network, especially in larger setups.

● Since data is broadcast to all devices, sensitive information can be intercepted by unintended recipients, posing significant security concerns.

● Hubs cannot filter or route data to specific devices. This makes them less efficient compared to switches and routers, which can intelligently direct traffic.

● Data can only flow in one direction at a time, which reduces overall network efficiency and increases the chances of data collisions.

● Hubs are not suitable for large or complex networks as they cannot manage or prioritize traffic effectively.

With advancements in networking, hubs have largely been replaced by more advanced devices like switches and routers, making them less practical in modern applications.

How to Connect a Network Hub?

Configuring a computer network hub is similar to configuring unmanaged Layer 2 switches. While the exact steps may vary depending on the model, the general procedure is as follows:

Step 1: Connect Power to the Hub: For active hubs that amplify signals, plug the hub into a power source using an AC power cord, wall adapter, or similar power connector.

Step 2: Link Devices to the Hub: Use Ethernet cables with RJ45 connectors to connect your devices to the hub’s network ports.

Step 3 [Optional]: Use the Uplink Port: While not typically needed in modern networks, some hubs include an "uplink" port to connect to another hub. These ports usually feature pre-configured pins that automatically swap the transmit (Tx) and receive (Rx) signals, eliminating the need for a crossover cable.

Step 4: Check Connectivity: After setting up, confirm that the network devices are communicating. Most hubs come with diagnostic LEDs that indicate power status, collision events, and port activity.

Troubleshooting Common Network Hub Issues

Some issues with network hubs are easy to diagnose, while others can be more complicated. Here's a guide to troubleshooting common hub-related issues:

1. Devices not communicating

If your devices connected in a hub network are not able to send or receive data, they might be facing this issue. You can simply resolve it by checking all cable connections to ensure they are secure and undamaged. You can also try replacing the cables or connecting the devices to different ports on the hub.

2. Slow Network or Lags

Hubs share bandwidth among all connected devices. If too many devices are active, the network can become congested and slow. If your connection feels slow or laggy, try reducing the number of devices connected to the hub.

3. Hub Ports not Working

If certain devices aren’t responding, the issue might be with specific ports on the hub. Test the non-working ports with known working devices and cables. If multiple ports fail, the hub may be defective and need replacement.

Top Network Hub Products

The table below shows some of the best hubs you can buy for your small office or home setups:

Should You Use a Hub in 2025?

No, using a hub in 2025 is not recommended for modern networks. They are outdated devices that send data to all connected devices, which can slow down performance and cause data collisions.

They don’t manage traffic or offer security features like switches and routers do. While hubs may still work in small, low-traffic setups or for basic monitoring, most users will benefit more from using switches, which are faster, smarter, and more secure.

If you're setting up a new network, choosing a switch is a better and more future-proof option.

Conclusion

A hub in computer networking is a straightforward yet foundational device that played a pivotal role in early LAN configurations. Although largely obsolete, hubs remain an important concept in networking education and history.

By understanding what a hub is and how it works, you can better appreciate the advances in modern networking technology.