Hubs vs. Switches: Understanding Their Role in Networking

Every wired network needs a central point where multiple devices connect and share data. For decades, two devices handled this job: the hub and the switch. They look almost identical from the outside, both are boxes with rows of ports, yet they work in completely different ways. Understanding the difference between them is one of the first steps in grasping how computer networks actually move information from one machine to another. This post breaks down what each device does, how they differ, and which one fits a given network setup.

What are hubs? 🔗

A hub is one of the simplest networking devices used to connect multiple computers and devices within a single local area network (LAN). It acts as a common connection point where every device plugs in through a cable. When you strip away the technical detail, a hub does one thing: it takes the data arriving on one port and copies it out to every other port.

Hubs operate at the physical layer, which is Layer 1 of the OSI model. At this layer, the device deals only with raw electrical signals or binary bits. It does not read addresses, inspect the contents of a message, or make any decision about where the data should go. When a hub receives a data packet at one of its ports, it sends it out as electrical signals to all the other ports. Because of this behaviour, a hub is often described as a multiport repeater.

How a hub-based network behaves 🔗

Picture four computers connected to a single hub. When Computer A wants to send a file to Computer C, the hub does not know which port leads to Computer C. So it broadcasts the data to Computers B, C, and D all at once. The intended device recognises the data meant for it, while the others simply discard what is not addressed to them. This is wasteful, because bandwidth is consumed sending information to devices that never asked for it.

Hubs also work in half-duplex mode, meaning they cannot send and receive data at the same time. When two devices attempt to transmit simultaneously on a half-duplex hub network, a collision occurs, forcing both devices to pause and try again. This slows the network noticeably as more devices are added. All devices connected to a hub share a single collision domain, so the more crowded the network becomes, the more collisions pile up.

Types of hubs 🔗

There are broadly two types of hubs. An active hub has its own power supply and can clean, amplify, and relay the signal across the network, which means it can also function as a repeater to extend the distance between nodes. A passive hub simply passes the signal along without strengthening it. Despite these variations, no hub adds any intelligence to traffic handling.

What are switches? 🔗

A switch performs the same basic job of connecting multiple devices, but it does so with far more intelligence. Instead of blindly broadcasting data to everyone, a switch sends it only to the device that is supposed to receive it. This single difference transforms how efficiently a network runs.

Switches operate at the data link layer, which is Layer 2 of the OSI model. Because it works at Layer 2, a switch can inspect received traffic and make forwarding decisions. The key piece of information it relies on is the MAC address (Media Access Control address), a unique hardware identifier assigned to every network adapter.

How a switch makes decisions 🔗

The intelligence of a switch comes from something called the MAC address table. Each switch maintains a dynamic table that maps MAC addresses to its ports, allowing it to identify which device is connected to which port and where to send an incoming frame. When a frame arrives, the switch reads the destination MAC address in its header and looks it up in the table.

If the destination address is found, the switch forwards the frame only to the correct port. If the destination MAC address is not yet in the table, the switch temporarily behaves like a hub and floods the frame to all ports except the one it arrived on, so the correct device can respond and the table can be updated. Over time, the switch learns the location of every device and rarely needs to flood traffic.

Why switches are faster and safer 🔗

Switches typically support full-duplex mode, which allows a device and the switch to send and receive data at the same time. Each switch port forms its own separate collision domain, and full-duplex operation effectively eliminates collisions while dedicating the full port bandwidth to the connected device. Because collisions are no longer expected, the older collision-detection method known as CSMA/CD is not required on these connections.

Switches also come in different forms. Managed switches can be configured and controlled, for example by assigning IP addresses through a console port, while unmanaged switches cannot be configured at all. Managed switches are common in larger organisations where administrators need fine control over how traffic flows.

Hub vs. switch comparison 🔗

While both devices connect multiple machines, the way they handle data sets them apart in speed, efficiency, and intelligence. Looking at them side by side makes the gap clear.

Data handling 🔗

This is the most fundamental difference. A hub broadcasts incoming data to all connected ports, regardless of the intended recipient. A switch forwards data only to the specific device that needs it. This means switches reduce unnecessary traffic and improve network speed, while hubs create congestion by flooding every port.

OSI layer and addressing 🔗

A hub operates at Layer 1 and works only with electrical signals, whereas a switch operates at Layer 2 and makes decisions based on MAC addresses. A hub has no awareness of who is connected to it. A switch builds and maintains a precise map of the devices on each port.

Duplex mode and collisions 🔗

A hub works in half-duplex and places every device in one shared collision domain, so collisions are frequent and grow worse as the network expands. A switch supports full-duplex and gives each port its own collision domain. A hub extends a single collision domain across all its ports, while a switch creates many smaller, separate collision domains, dramatically reducing collisions.

Speed and efficiency 🔗

Because a hub shares its total bandwidth among all connected devices, the available speed per device drops as more machines join. A switch dedicates the full bandwidth of each port to the device connected to it, so performance holds steady even on busy networks. Switches offer faster data transfer, better network performance, and more granular control over traffic.

Cost and complexity 🔗

Hubs were historically cheaper and simpler to set up, requiring almost no configuration. Switches are more sophisticated and were once more expensive, though prices have fallen sharply over the years. With improved technology, switches are now available cheaply, which has steadily reduced the cost advantage hubs once held.

Which one to use? 🔗

For almost every modern network, the answer is a switch. The efficiency, speed, and reduced collisions make it the clear default for homes, schools, offices, and large enterprises alike. Switches are steadily replacing hubs across most use cases because of their ability to pinpoint intended destinations.

When a hub might still appear 🔗

Hubs are now considered largely obsolete and are rarely sold or deployed in new networks. In modern networking, hubs are no longer used because their broadcast behaviour quickly leads to congestion and slow speeds. You may still encounter them in old equipment, in very small temporary setups, or in teaching labs where the goal is to demonstrate how broadcasting and collisions work. There are also specific situations, such as network monitoring or packet capture, where a hub’s habit of copying data to all ports can be useful for observing traffic, though dedicated tools have largely replaced even this use.

Choosing for different network sizes 🔗

For a small home network with a handful of devices, an unmanaged switch is inexpensive, plug-and-play, and far more capable than a hub. For a growing office, a managed switch offers control over traffic, the ability to create separate broadcast domains using VLANs, and room to scale. Switches are essential in business environments where networks must remain efficient and performant as more devices are added. The general rule is straightforward: if you are building or upgrading a network today, choose a switch.

Where switches fit alongside routers 🔗

It helps to know that a switch is not the same as a router. A switch channels incoming data to the correct port within a single network, while a router passes information between two or more separate networks by analysing IP addresses. In a typical setup, devices connect to a switch, and the switch connects to a router that links the local network to the wider internet. The switch handles internal traffic; the router handles the journey beyond.

What do you think? If hubs broadcast data to every device and switches send it only where it is needed, why do you think hubs survived in networks for as long as they did? And in what rare situations might a device that copies all traffic to every port actually be more useful than a smart, selective one?

References

1. https://www.geeksforgeeks.org/computer-networks/open-systems-interconnection-model-osi/
2. https://stl.tech/blog/difference-between-a-network-hub-and-network-switch/
3. https://www.coursera.org/articles/hub-vs-switch
4. https://study-ccna.com/network-switch-explained/
5. https://www.linkedin.com/pulse/layer-2-switching-ethernet-david-ramirez–bay8f
6. https://community.cisco.com/t5/networking-knowledge-base/network-switching-operation/ta-p/4193160
7. https://www.scaler.com/topics/computer-network/difference-between-hub-and-switch/
8. https://www.globalknowledge.com/us-en/resources/resource-library/articles/what-s-the-difference-between-hubs-switches-bridges/
9. https://itexamanswers.net/2-3-2-module-quiz-switching-concepts-answers.html
10. https://www.alliedtelesis.com/us/en/foundations/difference-between-network-switch-and-hub
11. https://www.geeksforgeeks.org/computer-networks/difference-between-hub-and-switch/
12. https://www.techtarget.com/searchnetworking/answer/Difference-between-a-router-switch-and-a-hub