What Is a Hub in Networking and How Does It Work?

The term “hub” is frequently mentioned in both casual and technical conversations, but what is a hub exactly, and why does it matter in networking? Whether you're sorting out your home office or learning the basics of networking, understanding how a hub works can save you time, confusion, and maybe even a few headaches. In this guide, we'll walk you through how hubs work, the different types out there, their pros and cons, and when it makes sense to use one.

What Is a Hub?

A hub is a basic networking device that connects multiple nodes, such as computers or other devices, in a Local Area Network (LAN). Think of it as a central point where all your Ethernet cables meet. When one device sends data into the hub, that data gets copied and sent out to every other device connected to it, whether they need it or not.

Hubs typically feature between 4 and 16 Ethernet ports, with a maximum bandwidth of 10-100 Mbps. They operate at Layer 1 of the OSI (Open Systems Interconnection) model—the physical layer—which means they only deal with the raw electrical or optical signals, not the actual data frames or packets. Because of this, all devices connected to a hub share the same collision domain.

How Does a Network Hub Work?

A network hub works by receiving data from one connected device and broadcasting that same data to all other devices within the network.

Let's say you've got a hub with five ports—A, B, C, D, and E—and a device plugged into each one. Here's how a network hub works:

1. Data is sent to the hub. The device on port A sends out a message (data packet). This message includes a destination MAC address, which is like the postal address for where the data is meant to go.
2. The hub broadcasts it to all other ports. Instead of figuring out which port the message should go to, the hub simply copies the data and sends it out to all the other ports at the same time.
3. Each device checks the message. 3.The devices on ports B, C, D, and E each receive the data and check the MAC address. If the address matches their own, they accept and process the data. If it doesn't, they ignore it.
4. Collisions can happen. 4.Because all devices share the same communication channel, if two devices try to send data at the same time, their messages collide. This results in a jam, and both devices have to wait and try again. This is managed by a system called CSMA/CD (Carrier Sense Multiple Access with Collision Detection), which helps control who gets to speak and when.

Because a hub broadcasts everything to every device, it's not very efficient, especially on busy networks. It also only supports half-duplex communication, meaning devices can either send or receive, but not both at the same time.

Different Types of Hubs

When you ask what are hubs, there are actually different kinds available. While they all serve the same basic purpose, the way they handle data can vary depending on the type.

Passive Hub

A passive hub is the simplest kind. It doesn't require power and doesn't process or amplify the signals it receives. It just takes the data from one device and passes it along to the others, as-is. This minimal circuitry makes a passive hub the cheapest option, but it also means your cable runs must be short and your traffic light.

Active Hub

An active hub goes one step further. It requires power and can amplify or regenerate signals before sending them out to the other ports. This helps maintain a stronger, more reliable connection over longer distances. You might also hear this type referred to as a “multiport repeater.”

Intelligent Hub

The most advanced of the bunch, an intelligent hub (or smart hub) includes additional features like traffic monitoring and error checking. While it still operates like a hub in terms of data broadcasting, it gives you a bit more control, useful for managing larger or more complex setups.

Advantages and Disadvantages of Using a Hub

Hubs are known for being simple, and depending on your needs, that can be both a strength and a weakness.

Why hubs can still be useful:

• Easy to set up: Just plug in your devices and you're good to go. No configuration needed.
• Affordable: Basic hubs are very inexpensive, making them a quick fix for small or temporary setups.
• Great for packet sniffing: Because a hub sends data to every device on the network, you can easily monitor traffic with a tool like Wireshark, without needing a port mirror or special switch.

Where hubs fall short:

• Network collisions: Since all devices share the same channel, only one can send data at a time. If two devices try to talk at once, their messages collide, leading to slowdowns and retries.
• Half-duplex communication: Hubs don't allow devices to send and receive data at the same time. This limits performance and can cause compatibility issues with modern full-duplex devices.
• No traffic filtering or security: Every device sees all the data, which isn't ideal for privacy or network efficiency. Anyone connected can potentially eavesdrop on the entire network.
• Outdated speeds: Most hubs top out at 10 or 100 Mbps, which is far slower than today's standard gigabit or multi-gigabit switches.

When Should You Use a Hub?

Hubs have mostly been replaced by switches in modern networks. But that doesn't mean they're completely obsolete. There are still a few specific cases where a hub can be the right tool for the job:

• Monitoring network traffic: If you want to capture all the data moving across a network segment (for diagnostics or security analysis), a hub is perfect. Unlike switches, it doesn't need special configuration to mirror traffic.
• Temporary or super-simple networks: Need a quick way to connect a couple of PCs or devices at a pop-up event, workshop, or lab bench? A hub is cheap, fast to set up, and good enough for basic file sharing or printing.
• Legacy or industrial systems: Some older equipment depends on broadcast traffic to function properly. In these cases, a hub ensures all devices receive the messages they're expecting.

For most everyday networking needs, though, a switch is the better choice. It's faster, more efficient, and much more secure. And in many cases, it doesn't cost much more either.

Conclusion

So, what is a hub? At its most basic, it's a simple networking device that lets multiple computers and devices connect and talk to each other within a local network. While hubs aren't as common today, thanks to more advanced options like switches and routers, they still have their place. They're affordable, easy to use, and ideal for small networks that don't handle a lot of data. That said, hubs do have their drawbacks. They don't manage traffic well and offer limited security, so they're really only suitable for basic networking needs.

FAQs

What is the difference between a hub and a switch?

A hub is a very simple networking device that operates at the physical layer (OSI Layer 1). When it receives a data packet on one port, it broadcasts that packet to all other ports, regardless of the intended recipient. By contrast, a switch works at the data‑link layer (OSI Layer 2). It reads each packet's MAC address and forwards the data only to the specific port where the destination device is connected. This intelligent packet forwarding reduces collisions, improves bandwidth efficiency and provides better overall network performance.

What is a hub in computer?

In computing, a hub is a basic networking device that connects multiple computers or devices in a local area network (LAN). It works by receiving data from one device and then broadcasting that data to all other devices connected to it. Hubs operate at the physical layer (Layer 1) of the OSI model and cannot filter or direct traffic. This simplicity makes hubs inexpensive, but also less efficient compared to more advanced devices like switches.