What Is a Computer Network Switch?
For any network, a switch is a device that channels all the incoming data from different input ports to the specific output port and further to the intended destination.
In the case of a local area network (LAN) that uses Ethernet, a network switch will determine where to send each message that comes in. The switches maintain tables that match the MAC address to the port from which the MAC address was received. If the frame is to be sent to a MAC address which is unknown to the switch, it is flooded to the ports in the switching domain.
Types of networking switches
There are some types of switches in the network along with the physical devices
Virtual switches are software only switches that are instantiated inside a virtual machine hosting environment.
A routing switch connects the LANs along with doing a MAC-based Layer 2 switching it can also be performed routing functions at OSI Layer 3 directing traffic based on the internet protocol address in each packet.
How does a network switch work?
A switch, whether virtual or physical, makes up a majority of the network devices that are used in the new network data. They can be provided to wired connections for desktop computers, industrial machinery, wireless access points, and also some internet of things devices for example card entry systems. They are what interconnect computes with host virtual machines in the data centers, along with dedicated physical servers, and storage infrastructure. They can carry vasts amounts of traffic in telecommunications provider networks.
You can deploy a network switch in the following ways
Aggregation, or distribution switches: these switches are placed inside an optional middle layer. The edge switches can connect into these intermediate layers and can send traffic from a switch to switch or send it directly up to the core switches.
Edge or aggregate switches: these switches manage traffic that either comes into or exits the network. A device like a computer or an access point can be connected using an edge switch.
Core Switches: These are network switches that are the backbone of the network. They either connect the aggregation or edge switches to one another. They can also be used to connect users or device edge networks to the data center network, typically connects enterprise LANs to the routers that connect them to the internet.
Many of the data centers have adopted a spine/leaf architecture that eliminates the middle aggregation layer. The design helps servers and storage connect to the leaf switches and the leaves connect to two or more spines or core switches. It minimizes the number of hops data that can take the data from source to destination and reduce the time that is spent on latency or transit.
A few data centers also use a fabric or mesh network that is designed to make every device look like it is on a single large switch. The approach can reduce latency to the absolute minimum and is used for applications that are highly demanding, for example, high-performance computing in engineering or financial services.
While switches make up 90% of networks, there are a few networks that do not have switches. A great example of this is a network that is arranged in a token ring or connected using a hub or bus or even a repeater. In this kind of system, every device that is connected here sees all of the traffic and reads all the traffic that is addressed to it. This network can also be established by directly connecting computers without the need for a separate layer of network devices.