What is An Ethernet Hub in a Network?

I published a series of tutorials for beginners to understand network engineering concepts on CoreNetworkZ Tech Solutions.

This post is part of my ongoing series on legacy networking devices. Today, I will explore one such piece of hardware—the network hub. Though largely obsolete in modern enterprise environments, some students asked me for a tutorial on the Hub.

On the support section of CoreNetworkZ Tech Solutions, many students asked questions (for CCNA and JNCIA-Junos).

So, I will explain a few Juniper JNCIA-Junos and CCNA questions from the Hub section. Let us first check the Hub and its role in a LAN.

Aishwarya Narayan, a CCNA aspirant from Chennai, asked, "What is a Hub, and in what OSI layer does this device operate?"

She asked this question on the support community of CoreNetworkZ Tech Solutions. I will answer her question in this section.

A Hub is a network device that connects multiple devices in a single network segment. It is a basic layer one connector without any intelligence.

That means we can connect multiple devices to a Hub. However, it has many limitations.

Now, I will answer Aishwarya's second question. The Hub operates at the Physical layer of the OSI Reference Model.

Let me add a few more points that will help her prepare for the coming CCNA examination.

Since it is a Layer 1 device, it cannot read the signals it transmits. In networking terms, all devices connected to a Hub feel as if they are on the same cable.

So, we can say that the Hub has a single collision domain. In other words, a Hub repeats the signal it receives.

Let us now check the working of a Hub. Vijay Nair, a regular reader of CoreNetworkZ Tech Solutions, asked, "Hello Alex, I am preparing for my CCNA examination. Can you explain the working of a network Hub in simple words?"

I will explain the operation of a Hub.

Consider a network including five devices and a Hub. Now, the first computer wants to send a packet to the fourth computer.

Let us see how the Hub handles this situation.

When a computer connected to a Hub sends packets, the Hub broadcasts the packets to all ports except the one from which it received the packets.

I believe I explained everything about the working of a Network Hub.

Aparna Rajeev, a B.Tech Student from Cochin, asked, "Why is no one using a Network Hub anymore? What are the limitations of a Hub?"

I ask you to recall my previous tutorial published on CoreNetworkZ Tech Solutions ( about the Switch).

Here, we can see the difference between a Switch and a Hub. A Hub does not read the packets; it simply broadcasts them to all ports.

A Switch, on the other hand, reads the packet and unicasts it. So, a Switch is more efficient than a Hub.

Another problem with the Hub is the higher chance of packet collisions. We know a Hub has a single collision domain, so the chances of collisions are very high.

I saw a comment on CoreNetworkZ Tech Solutions asking if anyone is using Network Hub.

I rarely see Hubs in a LAN to connect network devices. Most networks use Switches to connect multiple network devices in a single network.

However, it is an excellent device for a beginner in network engineering to create a dummy network in a lab. So, they can learn the basics of computer networking.