What is Ethernet Switch : Working & Its Applications

Ethernet networks utilize different networking hardware to ensure the connectivity of the device. So, the Ethernet switch is the most significant device among them. This switch uses the hardware addresses for connecting the devices very effectively, so it is considered the brain of a network. At present in computer networking or data center, the importance of these switches has been increasing so these are designed with different configurations & specifications. These switches are differentiated based on different factors like design, architecture, functionality, ports, etc. This article discusses an overview of an Ethernet switch – architecture, working with applications.

What is Ethernet Switch?

The switch which is used to connect wired devices like laptops, computers, servers, printers, and routers to a LAN or local area network is known as an Ethernet switch. This switch allows the various devices connected to the network for data exchange & communication with each other.

Ethernet Switch
Ethernet Switch

Several Ethernet switch ports let smoother access & faster connectivity across various devices immediately. This switch creates networks & utilizes many ports to communicate between different devices within the LAN.

Ethernet switches are different compared to routers because it connects networks & utilizes simply a single LAN & WAN ports whereas Hubs are related to Ethernet switches where the devices connected on the local area network will be connected to them with multiple ports. But the main difference between these two is; that hubs transmit bandwidth evenly between ports whereas Ethernet switches can offer more bandwidth to certain ports without corrupting the performance of a network. Whenever various devices on a network are active, the Ethernet switch gives a more robust performance.


The features of the Ethernet switch include the following.

  • An Ethernet switch operates at the data link layer/layer2 of the OSI model.
  • It has a higher number of ports.
  • This switch is an intelligent network device that can be considered a multiport network bridge.
  • This switch uses MAC (medium access control layer to transmit data packets to preferred ports).
  • It utilizes the packet switching method to forward & get data packets from the source to the destination device.
  • It supports unicast, multicast & broadcast communications.
  • The mode of transmission used in this is full-duplex.
  • These switches are known as active devices because they are equipped with the capabilities of a network management & network software.
  • Before sending data to the destination port these switches perform some error checking.

Ethernet Switch Architecture

The architecture of the Ethernet switch is shown below. We know that an Ethernet switch is mainly used to form a computer’s network & other devices. These switches are mainly used by network engineers to connect from one device to another. The main components in Ethernet switch architecture include CPU, replication engine, forwarding engine, switch fabric, controllers & buffers.

Ethernet Switch Architecture
Ethernet Switch Architecture


The CPU in the switch is accountable for handling all of the fundamental instructions on the device. The CPU is similar to how your mind is responsible for transmitting signals through your body to perform different things. Similarly, the CPU works like the brain of the Ethernet switch.

Replication Engine

The replication engine within an Ethernet switch is tasked with duplicating data packets & transmitting them to their selected destinations. In present organizations, it is becoming more common for only a data packet to be sent to several destinations within a network.

This maintains data flowing quickly & efficiently throughout the network by transmitting the duplicated packets of data at once in place of transmitting the single, unique data packet to the single destination before transmitting it to the next.

Forwarding Engine

The forwarding engine of this switch is the main component that is accountable for making all of the routings & switching decisions on the device. So as to achieve this, the forwarding engine includes lookup tables that transmit data packets to their suitable destination. Every data packet includes information like the source & destination packet’s address. The forwarding engine simply reads the address of the destination on the data packet & after that, it transmits there accordingly.

Switch Fabric

The switch fabric main concept can be quite difficult because it involves some difficult topics. Basically, the switch fabric includes hardware & software which contain the switching units enclosed in a network node & the software is necessary to control the switching lanes. The switch fabric is utilized as a metaphor to explain the relationship between the switching paths & ports.


The Virtual Output Queues is an extremely high-speed memory module, used to perform frame queueing within the silicon. Here, Queueing is required to check that the fabric is not overrun within the outbound way. In addition, packets that are arriving from the fabric shouldn’t overrun the MAC interfaces.


10G Media Access Control in Ethernet port offers up to 10 billion bits per second data speeds.


For line rate cryptography, an encryption processor is considered when using linksec.

How Does an Ethernet Switch Work?

A Ethernet switch works by learning the address and MAC (media access control) address of each device connected to it. It then uses this information to decide where data packets should be sent. For example, if one user sends data to another user on the same switch, then the switch will know where their computer is and will send the packet directly there instead of sending it along a long cable path that goes all around the building until it reaches its destination. By reducing network traffic and improving performance, switches help keep networks running smoothly and efficiently.

It’s function is similar to a hub, but it has more intelligence and higher performance than a hub. Unlike hubs, which use collisions to determine when they should send data, switches use de-collision. Switches also have the ability to store and forward frames, so they can send data even if there are no free ports left on the network segment. This means that if one computer sends a packet of data to another computer on the same network segment and there are no available ports for the switch to send that packet through, the switch will hold onto it until there are free ports available or until a designated timeout period has passed; in either case, it will then attempt to find another port to send the packet through.  When a packet arrives at an input port (or port), it is compared against a lookup table stored in memory within and accordingly the data is sent to the corresponding port.

For this it read the EtherType field of the ethernet header. Ether type field  in an Ethernet header is used to indicate the protocol type of the payload. An Ethernet switch uses this field to determine if the packet should be forwarded or dropped. For example The EtherType field is set to 0x0800 for IPv4 packets, so all switches drop packets with an EtherType other than 0x0800.

The switch will drop all packets with a destination MAC address that does not match its own MAC address. The switch should also be configured with a spanning tree protocol (STP) port priority and path cost value so that it will forward frames only through ports that have been correctly configured by STP.

If a switch receives more than one frame destined for the same port, it must use some mechanism to resolve the collision. In order to reduce collisions, most Ethernet switches use a CSMA/CD protocol when transmitting data on shared media segments.

It uses the CSMA/CD (Carrier Sense Multiple Access with Collision Detection) protocol to determine when to transmit data.

CSMA/CD is a protocol for sharing a single communication channel between multiple stations so that all stations have an equal opportunity to transmit data. When a station wants to send data, it first listens for any other traffic on the network cable. If there is no other traffic, the station sends its data. If the station detects another transmission, it will wait until the other transmission has completed before attempting to send its own data.

When two stations attempt to send data at the same time, they are said to be in collision. Each station receives an error message indicating that they have collided and should retry sending their data later.

The main difference between an Ethernet switch and hub is that an Ethernet switch can send a packet only to the port where the intended recipient resides, whereas a hub forwards all packets out every port except the port where it was received.

Ethernet switches come in many varieties, including:

Passive-matrix network switch – Passive matrix switches use an array of silicon diodes to determine which port should receive each incoming frame. This allows them to be less expensive than active-matrix switches but still be fast enough for most applications.

Active-matrix network switch – Active matrix switches use transistors instead of diodes as their switching elements. This allows them to be more energy efficient and also enables them to handle much higher speeds than passive-matrix switches can support

Ethernet Switch Ports

Ethernet switch ports are used for connecting network devices to a switch. These Ports have the physical openings to plug the data cables for connecting various devices. The classification of these ports can be done based on different factors like the following.

Based on Architecture

Ethernet switch ports are classified based on the architecture discussed below.

Access Port

This port is one type of connection on an Ethernet switch, used to transmit data from and to an exact VLAN. This port helps in connecting switches to different host devices like printers, desktops, laptops, etc.

Trunk Port

The trunk port on the switch is used to transmit data from & to several VLANs. This port is very helpful in connecting switches to other switches, servers, routers, etc.

Hybrid Port

A hybrid port in this switch is used to transmit data from and to one or several VLANs. This port is used in connecting different network devices and also user devices. This port simply supports both tagged & untagged frames from virtual LANs. This port also gets frames from VLANs simultaneously.

Based on Functionality

Ethernet switch ports are classified based on the functionality discussed below.

Combo Port

A Combo port is a compound port and it supports two dissimilar physical ports through similar port numbers & switches fabric although both the ports cannot be utilized at the same time. This port is very helpful in configuring the switch based on the requirements of the application.

Stack Port

This is one kind of special port, used for connecting by another same model, software version, and brand stackable switches to operate as a single stackable switch through port capacity equivalent to the amount of the combined switches. This port is helpful in making very long-distance connections.

PoE Port

In PoE port, the term PoE stands for Power over Ethernet. This port simply permits a single network cable for carrying power & data simultaneously. This port is used in different devices like IP security cameras or wireless network repeaters which utilize a single Ethernet cable for data, voice & power.

Based on Design

Switch ports are classified based on the design discussed below.

RJ45 Port

RJ45 or Registered Jack 45 port is used to communicate through other devices wherever networking of Ethernet is necessary. This port supports the speed of up to 100 Mbps and it is used in LANs, uplinks from desktop switches, server switching in data centers, etc.

SFP Port

An SFP Port or Small form-factor pluggable port on a network device is a slot where SFP transceivers are connected. It allows Gigabit switches for connecting to a variety of Ethernet & fiber cables for extending the functionality of switching through the network. This port supports upto 1 Gbps speed.

SFP+ Port

The advanced version of the SFP port is the SFP+ port which maintains high data rates with 10 Gbps speed. SFP+ transceiver cannot be inserted into SFP port as SFP+ does not support below 1Gbps speed.

SFP28 Port

The enhanced version of the SFP+ port is the SFP28 port which is mainly designed for the transmission of 25G signal. This port also supports the speed of up to 25 Gbps and is also used for upgrading the network.

QSFP+ Port

QSFP+ Port or Quad small form factor port mainly includes four lanes used to give support four times of speed to the corresponding SFP. This port supports a speed of up to 40 Gbps. This port includes an interface of 4-channel 10 Gbps SFP+

QSFP28 Port

Quad small form factor 28 port (QSFP28 Port) includes four lanes that support four times of speed the corresponding SFP. This port supports a speed of up to 100 Gbps. It includes 25 Gbps 4channel SFP28 interfaces.

Types of Ethernet Switch

Ethernet switches are available in two types managed and unmanaged switches which are discussed below.

Managed Switches

A managed switch offers a minimum of a hundred to a thousand configuration options which are very useful for corporate LANs and range from medium size to large. This kind of Ethernet switch has whole control on the network to arrange each port of Ethernet. Further, this assists in attaining the highest efficiency on the network through gigabit or 10-gigabit links. These types of switches allow the operator to arrange custom security policies of authorization & authentication when new devices are included in the network.

Managed Type
Managed Type

Unmanaged Switch

Unmanned switches are plug-and-play devices that require particular installation beyond an Ethernet cable. Its arrangement mainly depends on auto-negotiation between Ethernet devices which helps in allowing communication between them.

Unmanaged Type
Unmanaged Type

Further, this switch works like a port multiplier that recognizes automatically an appropriate data rate and switches between half-duplex & full-duplex modes.

These switches can be accessed by making changes physically by the operator & these switches provide the basic network access functionality without the requirement of customization. But, these types of switches do not offer security & flexibility like managed switches.

Please refer to this link to know more about Unmanaged Switch.

Ethernet Switch Vs Router

The difference between an Ethernet switch and a router includes the following.

Ethernet Switch


An ethernet switch is used to connect several networked devices within the network. The router is used to connect several switches & their equivalent networks.
This switch works on the second layer of the OSI model i.e, the data link layer. This router works on the 3rd layer of the OSI model i.e, the network layer.
Switches include different ports like 8, 16, 24, 48, and 64. A router includes two ports Fast Ethernet &  serial ports.
This switch cannot achieve NAT (Network Address Translation). This router can achieve (Network Address Translation).


It is used in a local area network.


It is used in local area networks or metropolitan area networks.
It provides simply port security. It provides safety measures to guard the network from safety threats.
The switch takes more time while making complicated routing decisions. A router can take a routing decision much faster than a switch.
These are called as semi-Intelligent devices. These are called Intelligent network devices.
It sends information from one device to another in the form of Frames (for the L2 switch) and the form of packets (for the L3 switch). It sends information from one network to another network in the form of data packets.


These switches work in any transmission mode like full or half-duplex. Routers work in only the full-duplex transmission mode but, we can modify it physically to work in half-duplex mode.
Switches work through the wired network. Routers work through both wired & wireless networks.
The Content Addressable Memory (CAM) table is used in this switch for the source & destination MAC address. The routing table is used in this router to obtain the best route for the destination IP.


The advantages of Ethernet Switch include the following.

  • These switches are very useful in reducing network downtime.
  • Network performance can be improved.
  • It increases the bandwidth available on your network.
  • It protects your business network with strong safety features
  • Decreases IT costs by remote management options & expenses of wiring.
  • It provides unique network switch connections for particular workstations for additional customization.
  • It increases the capacity of data transfer for the organization.
  • It decreases the burden on separate host PCs.

The disadvantages of Ethernet Switch include the following.

  • These switches are expensive.
  • The switch bridge failure can cause the network down.
  • Tracing a network connectivity issue is difficult by using a switch.
  • An Appropriate & most significant design is required to handle multicast packets.


The applications of Ethernet Switch include the following.

  • These switches play a key role in connecting wired devices like laptops, computers, servers, printers & routers to LAN.
  • This switch is a kind of network hardware and it is foundational to the internet as well as networking.
  • There are many Ethernet switch ports that allow very smoother access & quick connectivity across numerous devices.
  • This switch uses several ports and creates a network to communicate with different devices within the Local Area Network.
  • This is the most common type of network switch used in Ethernet for connecting different Ethernet devices through packet switching for processing, forwarding, and receiving data from one device to another.
  • This switch simply allows you to rotate one Ethernet cable into several wired connections.
  • This is a physical device that is normally found in office networks or homes.

Thus, this is all about an overview of an Ethernet switch – working with applications. This is a telecommunication device that is used to connect several devices or computers together to expand the network with no difficulty. There are different factors that need to consider while selecting an Ethernet switch like the speed of transmission, number of switch ports, the infrastructure of the network, features, price difference, and reliable vendor. Here is a question for you, what is networking?