What is a Network Switch?

Introduction

A Network Switch is a networking device that assist in connecting multiple computers or network devices. They play a significant role in the creation and management of networks as well as enhancing their performance, security, and scalability. By learning about network switches, we get insight about how networks function and how we can optimize them to suit network requirements. In this blog, we will explain what a network switch is, their history, use of switches in networking, and their advantages and disadvantages.

Switches form the backbone of networking and are one of the main building blocks of Local Area Networks (LAN). These are some of the basic devices that a network engineer must be familiar with and are covered under the CCNA Training. Let’s first understand what Network switches are.

What is a Network Switch?

A Network Switch acts as a network device that receives data packets from connected devices and directs them to their intended destination based on the information contained in the packet header. Generally, a Network Switch operates at the OSI model‘s data link layer (layer 2). Further switches can identify and process MAC addresses associated with devices.

Switches can also operate at the OSI model’s network layer (layer 3), allowing them to handle IP addresses and route packets between networks.

Below we have shown the Network Switch with the help of an image.

Working of Network Switch

The functioning of a Network Switch involves receiving data packets from one or multiple source devices and then forwarding them to one or more destination devices based on their MAC address. The following steps outline how a Network switch operates.

• When a data packet is received from a source device, the switch takes note of its source MAC address on one of its ports in its MAC address table.
• The switch then examines the destination MAC address of the packet by referring to its MAC address table.
• If the destination MAC address is found in the table indicating that it belongs to one of its devices, the switch forwards the packet to that port.
• In case the destination MAC address is not found in the table, or it is a broadcast or multicast address, the switch broadcasts this packet to all ports except for where it originated from (the source port).
• Finally, upon receiving this forwarded packet, which was intended for it specifically, the destination device acknowledges it by sending an acknowledgment to the source device.

Overall, this process allows switches to effectively manage network traffic by directing packets towards their intended destinations based on their MAC addresses.

History of Switches

The initial development of switches took place during the 1980s and early 1990s as an improvement over hubs. Hubs are the devices that broadcast all incoming data packets to every connected device. Hubs often result in network congestion and collisions since multiple devices could attempt to transmit data.

Network Switch resolved this issue by establishing individual collision domains for each port, which decreased the occurrence of collisions and improved the allocation for every device. Additionally, switches introduced capabilities like VLANs, QoS, security measures, and network management tools, thereby enhancing the functionality and performance of networks.

Now that we have a basic understanding of switches, let’s now discuss what are some of the uses of switches.

Different Uses of Switches in Networking

A Switch in Computer Network can be used for different purposes, some of which are:

• Creating LANs: With the help of switches, multiple computers, or other devices within a local area network (LAN) that includes a home network, an office network, or a campus network. The switch also allows fast and reliable communication among the connected devices within that LAN.
• Connecting LANs: Switches can also assist in connecting multiple LANs together to form a more extensive network like a MAN (Metropolitan Area Network) or a WAN (Wide Area Network). Additionally, switches allow the routing of packets between different LANs based on their IP addresses.
• Segmenting Networks: With the help of a switch, one can easily divide a large network into smaller segments, which, as a result, can improve the security, efficiency, and manageability of the network. Switches can also create VLANs (virtual LANs) that logically separate devices based on their functions, locations, or groups.
• Prioritizing Network: One can use a Network switch to assign different levels of priority or QoS (Quality of Service) to different types of traffic, such as voice, video, or data. It can ensure that only high-priority traffic has more bandwidth and low latency, whereas low-priority traffic has less bandwidth and higher latency.
• Securing Networks: Switch can implement various security measures in order to protect the network from unauthorized access to resources or devices. It can use various techniques such as authentication, encryption, firewall, and ACLs in order to secure the network.

We have discussed the history of switches along with its different uses in a network. Let’s now discuss the different types of switches in networking.

Types of Network Switches

There are different types of Network switches which are explained in detail below –

Unmanaged Switch

An unmanaged switch is an inexpensive switch that doesn’t require any configuration or management. It can be used out of the box without any user intervention. Unmanaged switches are ideal and are used for networks that don’t require control or customization.

Managed Switch

A managed switch is an advanced and costly option with various configuration and management features. Users can modify a managed switch through a web interface, command line interface (CLI), or network management software. These switches are best suited for networks that require control and customization.

Smart Switch

A smart switch falls in between a managed and unmanaged switch. It offers some configuration and management features. But not as many as a managed switch. Users can modify settings on a switch using either a web interface or network management software, making it suitable for medium-sized networks that need some level of control and customization.

Layer 2 Switch

Another type of switch is layer 2 switches, which operate at the data link layer of the OSI model. The primary purpose of these switches is to process the MAC addresses of devices. A Layer 2 switch can route packets within a network or VLAN.

Layer 3 Switch

A layer 3 switch is a type of switch that operates at both the data link layer and the network layer within the OSI model. It has the capability to identify and process both MAC addresses and IP addresses of devices. This means that a layer 3 switch can efficiently forward packets within or between networks or VLANs.

PoE Switch

A PoE or Power over Ethernet switch is a type of switch in computer network that is mainly used to supply power as well as data to other devices over Ethernet cables. This simplifies the installation and reduces the cost of wiring for devices such as IP cameras, wireless access points, or VoIP phones.

These are the various types of Switch in Computer Networks.

Features of Network Switches

Here are some features associated with switched –

• It runs on Layer 2, which means the data link layer of the OSI model.
• It can be imagined as a multiport network bridge which makes it an excellent network device.
• It transmits data packets to selected destination ports through MAC addresses.
• It receives and shares data packets from the source to the destination device with packet-switching strategy.
• It uses different methods for communication such as unicast (one-to-one), multicast (one-to-many), and broadcast (one-to-all).
• It avoids collisions because it transmits in full-duplex mode which means it communicates in the channel in both directions at the same time.
• It comes with the largest number of ports i.e. 24/48.

How To Set Up a Network Switch?

There are different types of switches that function based on defined tasks. A network switch ensures plugging into a port on the router for a home network or small network (LAN).

If you want to set up a network switch, the steps mentioned below will help you.

Step 1: You need to get a switch based on the network requirements.

Step 2: Now, connect the switch port directly to the router through a cable. (If the switch has an uplink port, you have to link the wire to that port or if it does not, then you must link it to any port of the router).

Step 3: After you complete all the connections, the IP addresses of the system are configured.

Why Are Network Switches Valuable?

Network switches are one of the things that play a crucial role in sharing information between various endpoints. Here are some points that explain why network switches are valuable:

• They ensure effective utilization of bandwidth as it communicates in full-duplex mode.
• These are used to facilitate wired connections to multiple devices such as IoT devices, printers, wireless points, etc.
• Network switches enable IoT devices to share data which creates a smart environment through artificial intelligence.
• Switches make up the network equipment that supports large amounts of traffic in telecommunications.

Switch vs Router vs Hub

The main difference between Switch, Router, and Hub is that Switches and routers are smarter than hubs. Switches direct data to specific devices, while routers send data packets to different networks. Furthermore, here are some key points to note –

Hub

• It works on Layer 1 i.e. Physical Layer of the OSI model
• It does not identify the source and destination
• It is cheaper than switches and routers
• It operates over a single LAN to connect devices
• It works through broadcast data
• On a hub, a single collision domain receives all ports

Switch

• It works on Layer 2 i.e. Data Link Layer of the OSI model
• It identifies the source and destination MAC addresses
• It is expensive compared to Hub
• It also works over a single LAN to connect devices
• It works through MAC address
• On a switch, each port has its own separate collision domain

Router

• It works on layer 3 of the OSI model i.e. network layer
• It identifies the source and destination IP addresses
• It is more expensive than the Switch
• It operates on different networks to connect devices. Often, it connects devices to a WAN
• It works through IP address
• On a router, each port has its own separate collision domain

Now, its time to understand its advantages and disadvantages.

Advantages of Network Switch

Some advantages of switches are:

• Improved performance that enables interference-free communication between devices.
• Provide more bandwidth for faster data transfer rates in the network.
• Dividing the network into smaller parts, reducing congestion and increasing efficiency.
• Enforces security with VLANs and access control lists, manages network traffic.
• Can be easily expanded by enabling network expansion by adding more switches.
• Use MAC address tables for automatic traffic forwarding, minimizing manual setup.

Disadvantages of Network Switch

Some disadvantages of network switches are –

• Switches can cost more than hubs, especially for advanced enterprise-grade models.
• Managing and configuring switches can create challenges in large, feature-rich networks.
• A switch failure can disrupt communications across its connected network segments, causing downtime.
• Improper configuration or overload reduces the data transfer rate.
• Despite security features, switches can be vulnerable to attacks if configured incorrectly.

Frequently Asked Questions

Q1. What is the computer switch?

A computer switch is a type of networking device that helps connect different types of devices within a network and forwards data packets to the intended device based on MAC address.

Q2. What is switch and hub?

Both the switch and hub are networking devices. Switch connects devices in a network and forwards data to the correct destination. Hub connects devices in a network but broadcasts data to all devices. Although Switch and Hub works similarly, there are various differences between Hub and Switch.

Q3. What is a switch and its functions?

A switch is a type of networking device that assists in connecting multiple devices as well as in transferring packets to the destination device.

Q4. What is a network switch example?

A network switch is used for different purposes. One such example is a switch that can be used in order to connect devices such as computers, printers, and many others and share data between these devices.

Conclusion

A network switch is a device that connects multiple devices on a computer network and forwards data packets to the destination device based on the MAC address of the packet. In this blog, we have discussed what a network switch is, its history, different uses of switches, how switches operate, and different types of switches.