Network Switches: What Are They and How Do They Work?

Written by Coursera Staff • Updated on Oct 30, 2024

Network switches are an important part of networking hardware. Discover how network switches create the foundations for enterprise computer networking.

[Featured Image] Six employees work at their computers and workstations thanks to an effective network switch that allows them to connect to the local area network seamlessly.

A network switch is a networking hardware component that connects devices in a local area network (LAN). It is sometimes called an Ethernet or LAN switch. Network switches route data packets, which are individually organized information, to their intended device by directing incoming traffic. They direct data packets within the LAN and from external sources such as a router connected to the Internet.

Continue reading to explore what a network switch is, how it functions, the types of switches, the advantages of switches in enterprise networks, and how to start your career in networking.

What is a network switch, and what is it used for?

In network topology, a network switch connects to a router, and any devices within that network plug into the switch using Ethernet cables. Network switches function at the data link layer (layer 2) in an OSI (open systems interconnection) seven-layer model of standardized networking protocols. Switches identify where to send data packets by identifying the MAC address unique to each device. When the switch receives a packet to one of the Ethernet ports, it uses the MAC address to specify which port to send the data packet to, then sends the data to the device.

Once a switch has sent a packet along a route one time, it begins to maintain a table and a list of MAC addresses that connect to that specific port. This table is called a lookup table (LUT). When a switch receives a data packet with a MAC address it has not seen, it uses a route, a type of LUT that sends the packet to all devices connected to a port. The device with the matching MAC address in the packet header receives the information, and the switch adds the address to its LUT.

Types of network switches

Because switches are such an essential component of an enterprise network, many different kinds of network switches exist to perform different tasks within a network, such as:

Managed switches
Unmanaged switches
Smart switches
PoE switches
Layer 2 vs layer 3 switches

Let’s take a closer look at each kind of switch and its best-use scenario.

1. Managed switches

Managed switches use hundreds of configuration options, making them perfect for enterprise use. The complex configuration methods mean network administrators manage switches using a command-line interface (CLI).

2. Unmanaged switches

Unlike managed switches, unmanaged switches are the most basic network switches. Produced for small LANs, they have few configuration options and mostly group PCs or network devices on a network. With little customization, they are the cheapest network switch and provide simple networking solutions.

3. Smart switches

Smart switches provide a more automated configuration than managed switches and only come with some customizable features, such as virtual LANs (VLANs), service settings, and configuration through a graphical user interface (GUI).

4. PoE switches

A power over Ethernet (PoE) switch uses Ethernet cables that also contain copper wire to send power and data in the same cable. The switch can then power other devices connected to it. If additional devices need power, PoE switches can do that, but if other IoT devices do not require power in this way, non-PoE switches are less expensive.

Layer 2 vs. layer 3 switches

Layer 2 switches the kinds of switches this article has discussed thus far. These switches, or multiport bridges, are hardware devices that send data packets to devices with MAC addresses. They move data packets from one port to another or a VLAN and require a connection to a router that can route IP packets.

However, large networks with constant routing might use a layer 3 switch, which combines aspects of a router and a switch into one device. Layer 3 switches are also known as multilayer switches. Networks with lots of VLAN segmentation benefit from using layer 3 switches since they direct data packets using their IP address, which gives these switches the ability to direct packets through different subnets and VLANs.

While layer 3 switches have some routing capabilities, they do not have all complex routing protocols, such as OSPF, BGP, and EIGRP. With the large number of ports found in a typical layer 2 switch, layer 3 switches increase routing speed and manage traffic better.

Advantages and disadvantages of network switches

Network switches are an essential part of any computer networking system. The chart below examines some of their advantages and disadvantages in more detail.

Advantages	Disadvantages
Network switches optimize network bandwidth by creating connections between every device in the network.	Network switches require an understanding of networking fundamentals to properly set up and manage.
They reduce network congestion by only sending data packets to the device’s MAC address listed in the header.	As networks and the number of switches used grows, so does the challenge of managing and maintaining the network.
Since switches learn the MAC address of the device connected to the port, they lower the latency of packet transmission.	Switches face security issues and network inefficiencies if not configured properly, leading to network vulnerability and congestion.
Switches improve security and network management since a network administrator manages them.	Network switches typically require hardware upgrades since older switches may not support new networking protocols and technologies.
Network switches are scalable and cost-effective hardware components for growing networks that need fast speeds.	More switches with more ports increase energy costs.

All networks use switches to some degree, but large-scale organizations use switches extensively to create subnetworks and VLANs that optimize security features and connect many devices together. Network engineers work within an organization to improve the network, and switches are important in collecting data on how networks function overall. Some switches even use machine learning to optimize the network.

How to get started in networking

To enter a career in networking, employers typically want a bachelor’s degree in networking or a relevant field. You can also earn certifications in IT to prove your understanding of networking concepts to potential employers. One of the most common skills for those working in networking is switches, so leverage your knowledge of it on your resume.

Let’s take a look at some jobs in networking and their average annual US salaries:

Network technician: $62,243
Network support specialist: $67,834
Server administrator: $76,185
Network administrator: $78,638
Network engineer: $83,809
Cloud engineer: $114,793
Network security engineer: $117,239
Network architect: $141,726

*All salary data is sourced from Glassdoor as of October 2024

Getting started with Coursera

For consumers, network switches are valuable for adding more ethernet ports and security for LAN traffic. Enterprises use the bandwidth, efficient traffic routing, network administrator management, and advanced security measures. Continue learning about network switches and other networking fundamentals to upskill at your current job or start a career in networking on Coursera. For example, you might consider trying the Google IT Support Professional Certificate or Information Technology (IT) and Cloud Fundamentals Specialization from IBM, both easily accessible as beginner-friendly online courses that can help build your skill set and knowledge base.

Keep reading

Updated on Oct 30, 2024

Written by:

Coursera Staff

Editorial Team

Coursera’s editorial team is comprised of highly experienced professional editors, writers, and fact...

This content has been made available for informational purposes only. Learners are advised to conduct additional research to ensure that courses and other credentials pursued meet their personal, professional, and financial goals.