Skip to content

Ethernet Switches vs Hubs: A Comprehensive Guide for IT Professionals

As a digital technology expert with decades of experience designing and troubleshooting enterprise networks, I‘ve seen firsthand the dramatic evolution of Ethernet over the years. One of the most significant developments was the transition away from Ethernet hubs to switches in the late 1990s. While both devices serve as central connection points for network devices, they go about their business in very different ways. In this in-depth guide, I‘ll share my expertise to highlight the key technical differences between switches and hubs and explain why switches are the hands-down best choice for modern networks.

Ethernet Hubs: A Relic of the Past

Ethernet hubs ruled the networking world in the early days of Ethernet, but their reign was short-lived. A hub is a very simple device that operates at Layer 1 (the physical layer) of the OSI model. Its sole purpose is to take an incoming packet and broadcast it out to every other port, without any regard for where the packet actually needs to go.

This behavior is known as frame flooding, and it means that every single packet is sent to every single device connected to the hub, whether it was meant for that device or not. The destination device will keep the packet, while the others will determine it wasn‘t intended for them and drop it.

The Trouble With Hubs

This indiscriminate flooding of traffic leads to some serious performance and security issues, which is why hubs quickly fell out of favor as networks grew. Some of the biggest issues with hubs include:

  • Shared bandwidth: All devices connected to a hub share the same bandwidth. So even though each port might be capable of 10 or 100 Mbps, that bandwidth is divided across all the devices. The more devices connected, the less bandwidth available to each.

  • Half-duplex communication: Hubs operate in half-duplex mode, meaning devices can only send or receive data at one time, not simultaneously. This leads to frequent collisions when two devices transmit at the same time.

  • Congestion and collisions: Since every device sees all the traffic, packet collisions are very common on hub networks. Hubs use a protocol called CSMA/CD (carrier-sense multiple access with collision detection) to deal with collisions by having devices wait and retransmit packets, but it‘s an inefficient process that wastes bandwidth.

  • Limited scalability: Due to the collision and bandwidth issues, performance rapidly drops off as devices are added to a hub. Hubs with more than a dozen or so devices become basically unusable. The old 5-4-3 rule of Ethernet specified that hubs could only have 5 segments, 4 repeaters, and 3 mixing segments to limit collisions.

  • Security issues: The frame flooding behavior of hubs means every device sees traffic intended for other devices, opening up big security holes. There‘s no way to control which devices can communicate or segment traffic.

Hubs Are Now Obsolete

These drawbacks led to Ethernet hubs being declared obsolete by the IEEE 802.3 specification in 2011. Hubs have been almost entirely replaced by switches in enterprise and home networks due to their vastly superior performance, efficiency, and security. The only remaining use cases for hubs are legacy systems that require them and extremely cheap basic networks with no performance or security requirements.

Ethernet Switches: The Modern Standard

In contrast to hubs, Ethernet switches are highly intelligent devices that operate at Layer 2 (the data link layer) of the OSI model. Switches are purpose-built to boost network performance and efficiency by intelligently directing traffic only where it needs to go.

How Switches Work

Instead of mindlessly flooding all traffic out of every port, switches inspect each incoming Ethernet frame and selectively forward it out the appropriate port based on its destination MAC address. Switches maintain what‘s called a MAC address table that dynamically learns and maps the MAC addresses of connected devices to the physical ports on the switch.

Here‘s a simplified example of how switching works:

  1. Device A wants to send data to Device B. It creates an Ethernet frame containing the source and destination MAC addresses and sends it to the switch.

  2. The switch receives the frame and examines the source MAC address. It adds an entry to its MAC address table mapping Device A‘s address to the port it arrived on, if the entry doesn‘t already exist.

  3. The switch then looks at the destination MAC address of the frame and consults its address table to determine which port Device B is connected to.

  4. If the switch has an entry for Device B‘s MAC address, it forwards the frame out the corresponding port to Device B. If no entry is found, the switch floods the frame out of all ports except the one it arrived on (just like a hub).

  5. Device B receives the frame and processes it, while the other devices simply drop the frame since it wasn‘t addressed to them.

This selective forwarding process makes switches much more efficient than hubs. Traffic is only sent to the intended recipient, not every device, which eliminates collisions and dramatically improves performance.

Key Benefits of Switches

Switches offer numerous advantages over hubs, including:

  • Dedicated bandwidth: Each port on a switch provides full dedicated bandwidth to the connected device. For example, a 48-port gigabit switch can provide each device with a full 1000 Mbps, for a total switching capacity of 48 Gbps.

  • Full-duplex communication: Switches operate in full-duplex mode, meaning devices can send and receive data simultaneously without collisions.

  • High port density: Switches are available with up to 48 ports or more in a single 1U rackmount form factor, allowing for high-density connectivity.

  • Scalability: Switches can be connected to each other via special uplink or stacking ports, allowing networks to scale to hundreds or thousands of devices.

  • Advanced management: Managed switches support advanced features like VLANs for traffic segmentation, Quality of Service (QoS) for traffic prioritization, link aggregation for increased bandwidth, and port mirroring for monitoring.

  • Power over Ethernet (PoE): Many switches can provide power to connected devices like IP phones, cameras and access points over the Ethernet cable, eliminating the need for separate power supplies.

  • Improved security: Switches can be configured with port-level security to control which devices can connect to the network. They also support authentication protocols like 802.1X to further restrict access.

With all these benefits, it‘s no wonder that switches have become the de facto standard for Ethernet connectivity in enterprise networks.

Switches vs Hubs: By the Numbers

To quantify the difference between switches and hubs, let‘s take a look at some real-world performance benchmarks. In a test conducted by Cisco, a network with 100 devices connected via hubs experienced a 90% reduction in throughput compared to when the same devices were connected to a switch.

Another study found that a network with just 12 devices connected to a hub had 41% of its total bandwidth consumed by packet collisions. When the same devices were connected to a switch, there were no collisions and each device was able to use its full dedicated bandwidth.

To further illustrate, consider a 24-port 10/100 hub vs a 24-port 10/100 switch:

Metric 10/100 Hub 10/100 Switch
Total bandwidth 10 or 100 Mbps shared 2400 Mbps (24 x 100 Mbps)
Bandwidth per port 10 or 100 Mbps / 24 Dedicated 10 or 100 Mbps
Duplex Half-duplex Full-duplex
Packet collisions High None
Latency High Low
Max devices supported 24 (at very low performance) Hundreds with stacking

As you can see, switches provide orders of magnitude better performance across every metric.

Choosing the Right Ethernet Switch

With switches being the clear choice for most applications, the next step is selecting the right switch for your network. Key factors to consider include:

  • Port density: Choose a switch with enough ports to accommodate all your devices, with some room for future growth. Consider uplinks and/or stacking ports if you need to scale beyond a single switch.

  • Speed: 10/100 Mbps is sufficient for most network devices, but traffic-heavy devices like servers and storage should use Gigabit (1000 Mbps). 10G/40G/100G speeds are available for extremely demanding applications.

  • Power over Ethernet (PoE): If you plan to connect PoE devices, make sure to select a switch that provides sufficient power output for your needs. Different levels of PoE provide different amounts of power.

  • Management: Unmanaged switches are plug-and-play, but offer no configuration options. Managed switches allow you to configure advanced features like VLANs, QoS and link aggregation, but require more knowledge to set up.

  • Form factor: Switches come in desktop and rackmount form factors, with different port densities. Consider where you plan to locate the switch and how it will physically connect to other devices.

  • Budget: Entry-level unmanaged switches can cost less than $50, while enterprise-class modular switches can cost tens of thousands of dollars. Determine what features and performance you realistically need and select the appropriate switch to meet those requirements.

The Future of Ethernet Switching

The Ethernet switching market continues to evolve to meet the ever-increasing demands for more bandwidth, lower latency, and higher port densities. Some key trends and emerging technologies include:

  • Multigigabit Ethernet: Speeds of 2.5, 5, and 10 Gbps over existing Cat 5e/6 cabling to support high-bandwidth applications without re-cabling.

  • 25/50/100/400 Gigabit Ethernet: Newer switch models are pushing speeds to 400 Gbps and beyond to support ultra-high-performance data center, cloud, and service provider networks.

  • Software-defined networking (SDN): Decouples the network control and forwarding functions to enable more automated and efficient network configuration and management.

  • Intent-based networking: Uses machine learning and advanced automation to continuously align the network with desired business outcomes. Monitors and adjusts network performance in real-time.

While the specifics may change, the core benefits of Ethernet switching – high performance, efficiency, and scalability – will continue to play a central role in enterprise networking for the foreseeable future. Switches have already cemented their place as the successor to hubs, and they will remain a foundational technology as networks continue to evolve.

Conclusion

In the battle of Ethernet switches vs hubs, switches emerge as the clear and decisive victor. The performance, security, and scalability advantages of switches are simply too great to ignore in modern network environments. Hubs had their moment in the early days of Ethernet, but their serious deficiencies quickly became apparent as networks grew and performance demands increased.

Today, Ethernet switches have become the standard method of connecting devices in LANs across businesses of all sizes, from small offices to large enterprises. Their intelligent traffic management, full-duplex communication, and high port density make them an essential tool for building fast, efficient, and secure networks.

While alternative technologies like powerline and wireless mesh networking have their place, Ethernet switching will continue to form the backbone of enterprise connectivity for the foreseeable future. As speeds continue to climb and new management paradigms emerge, Ethernet switches will evolve to meet the changing needs of businesses.

The choice between a switch and a hub in 2023 is an easy one. But choosing the right switch for your specific environment requires carefully evaluating your performance requirements, growth plans, and budget. By understanding the key features and trade-offs of different switch models, you can build a robust and future-proof network that will support your business for years to come.

As an IT professional, staying up-to-date on the latest Ethernet switching technologies and best practices is essential for designing and managing high-performance networks. The world of networking never stops evolving – make sure your knowledge and skills evolve with it!