What is a Switch in Computer Networks?

Did you know that the average office network can have over 100 devices connected to a single switch at any time? As networks continue to grow and become more complex, managing traffic efficiently becomes more critical than ever.

A switch in computer networks is at the heart of this management, directing data packets between devices within a network. Understanding the role of switches and how they differ from other network devices, such as routers, is key to maintaining a smooth and reliable network infrastructure.

In this article, we will learn about network switches, look at various types of switches and switching techniques. We have also shared some popular network switches in the market and their prices.

Further, if you are interested in learning practical skills with network switches, you can join our networking training courses. 

What is a Switch in Computer Networks? 

A switch in computer networks is a device that connects various devices (like computers, printers, or servers) within a Local Area Network (LAN).

It works by receiving data packets from one device and forwarding them to the intended destination device. Unlike simple hubs, which broadcast data to all devices, a switch network device is much smarter.

It learns the MAC (Media Access Control) addresses of the connected devices and only sends data to the correct destination. This selective forwarding of data ensures that network traffic is kept efficient and reduces unnecessary congestion.

Did you know?
The first multi-port network switch, known as a MAC Bridge, was invented in 1983 by Mark Kempf, an engineer at Digital Equipment Corporation. 

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How Does a Network Switch Work?  

In a switch network device, a device used to connect multiple devices within a local area network (LAN), enabling them to communicate with each other.

Here is how a network switch works.

1. MAC Address Learning 

When a device (e.g., a computer or printer) sends data to the network, the switch records the device's MAC (Media Access Control) address along with the port on which it was received. 

This is done by examining the source MAC address in the incoming Ethernet frame and mapping it to the corresponding port in its MAC address table (also known as the forwarding table). 

2. Forwarding Data 

When the switch receives data intended for a specific device, it checks the destination MAC address in the incoming frame. 

It then looks up the destination MAC address in its MAC address table to determine which port to forward the data to. 

If the switch has a record of the destination device's MAC address, it sends the data only to that specific port. 

3. Flooding (When Unknown Addresses) 

If the switch doesn’t know the destination MAC address (i.e., the address is not in its MAC address table), it will flood the data to all connected ports, except the one it received the data on. 

Once the destination device responds, the switch learns its MAC address and updates its table to send future data directly to that device. 

4. Switching Frames 

The switch operates at Layer 2 (Data Link Layer) of the OSI model, meaning it works with Ethernet frames. 

It processes these frames by checking the Ethernet header, extracting the source and destination MAC addresses, and forwarding the frame appropriately. 

5. Full Duplex Communication 

Most modern switches support full-duplex communication, allowing devices to send and receive data simultaneously. This increases the efficiency and speed of communication on the network. 

6. Virtual LANs (VLANs) 

Switches can also segment a network into VLANs, creating isolated logical networks within the same physical switch. This improves security and network performance by limiting broadcast traffic to specific VLANs. 

7. Error Checking 

Switches can detect errors in incoming frames, such as CRC (Cyclic Redundancy Check) errors, and discard faulty frames before forwarding them. 

8. Security and Control Features 

Many modern switches offer security features such as port security, which can limit the number of devices that can connect to each port, and Quality of Service (QoS) to prioritize certain types of traffic. 

Where are Switches Used in a Computer Network?

To understand the use of switches in networking, imagine you have a small office network with several computers, a printer, and a server. All these devices are connected to a network switch. 

When Computer A wants to send a file to Printer P, the switch looks at the destination device’s MAC address and only sends the data to the printer, rather than broadcasting it to every device on the network. 

Similarly, when Computer B needs to access Server S, the switch forwards the data only to the server, ensuring other devices aren’t burdened with unnecessary traffic. 

By directing data to the correct destination, the switch optimizes the network’s performance, reduces congestion, and improves security since data is only shared between the relevant devices.

Switching techniques 

Switching techniques refer to methods used to route data across networks, ensuring that information reaches its intended destination efficiently. 

● Circuit Switching 

● Packet Switching 

● Message Switching 

● Cell Switching 

● Hybrid Switching 

We have covered in detail the switching techniques and modes, which you can read in the next article.

Types of Switches in Computer Networks  

There are different types of network switches used in an IT infrastructure. Each type of switch offers different features and capabilities to meet the needs of different network sizes and complexities. 

1. Managed Switches 

Managed switches offer advanced network control, supporting features like CLI configurations, SNMP for monitoring, and VLANs for traffic segmentation. They are ideal for complex networks requiring detailed management, security, and performance optimization. These switches come at a higher cost but are essential for enterprise environments. 

2. Unmanaged Switches 

Unmanaged switches are simple, plug-and-play devices with minimal configuration options, mainly used to expand a LAN. They use MAC addresses to forward data, making them suitable for smaller, less complex networks. Affordable and easy to use, they provide basic functionality without advanced features. 

3. Power over Ethernet (PoE) Switches 

PoE switches deliver both data and power over a single Ethernet cable, simplifying device installation without needing separate power sources. They are commonly used for IP cameras, phones, and wireless access points. PoE switches reduce wiring complexity, especially in areas where adding power outlets is challenging.

Read About Different Network Cables

4. LAN Switches 

LAN switches manage data traffic within a localized network, optimizing bandwidth and reducing congestion. They ensure data reaches its destination efficiently, improving network performance. These switches are crucial for internal communication within organizations. 

5. Smart Switches 

Smart switches offer more control than unmanaged switches but are less complex than fully managed ones. They support features like VLANs and port mirroring, making them suitable for small to medium-sized networks. Smart switches balance affordability and network management capabilities. 

6. Modular Switches 

Modular switches provide flexibility by allowing the addition of expansion modules as networks grow. These modules can include extra ports or advanced functionalities, such as wireless support. They are ideal for large networks needing scalability and customization. 

7. Fixed-Configuration Switches 

Fixed-configuration switches are pre-configured with a set number of ports and cannot be expanded. They are cost-effective and reliable for small to medium-sized networks where scalability is not a concern. These switches provide stable network solutions with fixed features. 

8. Stackable Switches 

Stackable switches can be connected to form a unified system, simplifying management and expanding network capacity. These switches offer centralized configuration, redundancy, and performance enhancements like link aggregation. They are ideal for growing networks that require scalability and reliability. 

9. Layer 3 Switches 

Layer 3 switches combine switching and routing capabilities, functioning at the network layer to route data based on IP addresses. They offer faster routing speeds than traditional routers, making them ideal for large, complex networks. These switches support dynamic routing protocols and are used in enterprise-level environments. 

10. Data Center Switches 

Data center switches are designed to handle high-speed, high-volume data traffic in large-scale IT environments. They support virtualization, enhanced security, and QoS for efficient data processing. These switches are critical for ensuring reliable performance in data centers with demanding workloads. 

11. Switches with Optical Fiber Ports 

Switches with optical fiber ports use fiber optic cables for high-speed, long-distance data transmission. They provide superior bandwidth and lower latency compared to copper cables, making them ideal for large-scale or high-demand networks. These switches are used to connect distant locations or extend network reach. 

12. Keyboard, Video, and Mouse (KVM) Switch 

KVM switches allow control of multiple computers with a single set of peripherals, reducing cable clutter and simplifying management. They are especially useful in server rooms or data centers for managing several systems simultaneously. KVM switches enhance workflow efficiency by enabling quick switching between devices. 

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What is the difference between a Switch, a Router, and a Hub?

Switches, routers, and hubs are used to connect different devices but the primary difference between them lies in what type of connectivity they provide.

In this table, we have compared Switch vs Router vs Hub: 

Learn More about the OSI Model. 

Top Switches and Their Prices

Benefits of a Switch in Networking 

● Switches enhance efficiency by forwarding data only to its intended recipient, reducing network congestion and ensuring faster data transmission. 

● Switches transmit data packets directly to the correct device using its MAC address, minimizing unauthorized access and enhancing data security. 

● Switches support network growth by maintaining performance with dedicated communication paths and offering features like VLANs for traffic segregation. 

● Unlike hubs, switches prevent data collisions by providing separate communication paths, ensuring reliable and efficient network performance. 

● Advanced switches prioritize critical traffic, like VoIP and video conferencing, ensuring low latency and consistent performance for essential applications. 

Conclusion 

The switch in networking plays an essential role in the efficient operation of modern computer networks.

By understanding how switches in computer networks operate, the different types of switches in computer networks, and how they compare with routers, network administrators can design and manage networks that are optimized for speed, efficiency, and scalability.

Whether for small-scale environments or large enterprise networks, switches are critical components that help devices communicate effectively within a network.