How Does a Network Switch Work
How does a Network Switch Work

A network switch refers to the hardware component operating at the Data Link Layer of the OSI model and connecting devices on the computer network utilizing packet switching. So, it is the one that connects and transmits data packets among devices available on the local area network.

It is concerned with information distribution to one device for which it has been designed, including a router, switches, or a computer. However, these switches are an integral part of the entire enterprise as the network forms the critical base for supporting the companies and their connected devices to run smoothly.

Generally, these switches function at the data link Layer 2 of the OSI architecture. Here it receives the data packets from the access points, which remain linked to the physical ports, only to send them to the destination device via the ports.

In layman's terms, network switches can connect devices like computers, printers, access points, etc., to help users exchange data packets over the network. Typically, these network switches work in three different ways:

  • Edge or access switches are responsible for maintaining incoming and outgoing traffic through a network. These link various devices, including access points as well as personal computers.
  • Core switches form the backbone of the network. They are responsible for linking the edge or aggregation switches or consumer edge networks to the ones at the data centers, along with the routers to organizational LANs.
  • Aggregation switches are the ones that are present within the optional intermediary layer. These can connect to the edge or access switches to transmit traffic from one switch to the other or maybe to the core switches.

Therefore, a network switch functions as the multiport bridge for networks that operate at OSI Layer 2. In addition, a few switches can forward data to Layer 3 as they demonstrate routing functionality. So, these switches are an essential component of the networks based on Fibre Channel, Ethernet, Asynchronous Transfer Mode (ATM), InfiniBand, etc. However, most of them now use Ethernet.

Network Switch

So, how exactly do these network switches function? Let's find out here:

Packet Obtaining & Switching

Generally, the Ethernet switch is responsible for performing all necessary activities on the data link layer devices, and IPs generate the data packets, which remain available in the Ethernet frame. The network devices are responsible for data transmission, which occurs via packet switching and is done seamlessly with the help of these switches across digital networks.

Packet switching is done by breaking down the data into specific packets or blocks for transferring them efficiently using different network devices. For example, every time a device sends a file to another, it simply breaks it down into data packets to calculate the time and route for sending the data across that network. Following this, the network devices route these data packets to the specific receiving destination, where the pre-destined device reassembles the received data for further use.

Packet switching

Encapsulation

Since you have already understood the primary data transmission process through the network devices, let's check out how these switches help carry the data from one location to another without any interruptions. Encapsulation occurs when the bits of information adhere to the back and front of the packets for transmission. It generally occurs in TCP/IP or OSI models.

Encapsulation indicates the portions of the data packet, where the beginning part is known as the header while the end one is known as the trailer. The data that resides between these two parts is called the payload.

Data header and trailer

Processing & Forwarding Data Packets

After the data is encapsulated, it is identified and processed per the pre-defined delivery destination. The switch fetches all the required information only when the frame reaches it and then forwards it to the destination within the scheduled deadline.

So, when you connect any device to a particular network switch, it notes the device’s MAC address which is a code that’s available in the network-interface card (NIC) of the device. This NIC then attaches to the Ethernet cable to establish the connection with the switch. The switch, in turn, uses this MAC address to identify the outgoing data packets from the device and the delivery destination.

The MAC address will then identify the physical device while the Layer 3 IP address is dynamically assigned. When this data packet enters the network switch, it reads the header and matches the delivery address to send it through the appropriate ports. Most of these switches offer full-duplex functionality to lower any chance of collisions between the switches and network traffic. That means the data packets can enter and leave the device having access to the full bandwidth of the network switch connection.

Store and Forward Switching

For a more detailed working principle of the network switches, check out

What are Network Switches Used for?

The benefits of network switches are:

  1. Network traffic offloading
  2. Seamless connection with different hosts
  3. LAN bandwidth optimization
  4. MAC filtering

Network Traffic Offloading

The network switches' function is to regulate traffic through network devices like wireless access points and computers. It is chiefly known as forwarding, where the incoming network traffic is forwarded to the connected device to deliver the data at the predefined destination switch port.

Network switches also offer performance analysis and intrusion detection while making the process of setting up firewalls simpler. In addition, it aids in future analysis by enabling port mirroring, which makes a mirror copy of the data while it travels through the switch.

Seamless Connection with Different Hosts

A network switch comes with multiple ports for connecting cables, thereby helping establish a seamless connection between devices and the network system. One can use these switches to connect computers, irrespective of location, to the network system, as the primary goal is to move the data packets from one computer to another.

So, these network switches are beneficial for data transportation along the route regardless of the physical distance between devices. Furthermore, since each port available on the network switch comes with the same filtering or forwarding mechanism, one can have multiple ports linked by cascading these switches together while operating them individually within the group.

LAN Bandwidth Optimization

Network switches function at OSI model levels like data links, transport layers, etc. Hence these can enable effective switching, which can effectively handle the increased network traffic from videos and other such high bandwidth-intensive applications. So, it helps in bandwidth optimization even when more data packets are destined for the servers.

It is solely possible as these switches can divide the LAN network into multiple collision domains resulting in increasing the frequency band. So, any small or even mid-sized enterprise can use LAN switching to maintain speed and reliability.

MAC Filtering

Filtering the use case of network switches requires a special mention here. Such functionality of these switches enables the user to prevent specific nodes from connecting. It is a security procedure that is based on access control.

These switches store a long list of MAC addresses and forward the data packets only to the assigned ports. Depending on the network access control requirements, this MAC filtering helps add an additional layer of security to the device's MAC addresses to reduce unwanted access to data.

Network Switches Function

How to Select the Best Network Switch?

Connecting to different brands and knowing about their key offerings can help businesses to find the best network switches for their companies. However, it is essential to know different types of network switches to get the appropriate benefits.

For example, how do you select between managed vs. unmanaged switches for your business? Understanding the key features and functionalities will help you shortlist the right brand and products for your enterprise. In case of doubts, we can help you at DC Gears.

DC Gears partners with the top brands offering network security and cybersecurity solutions globally at exceptional prices. We are available in more than 40+ countries and provide you with the best professional expertise on-site, 24*7. Get in touch with us for the best price quote on network switches and other data center products.