Understanding the difference between Layer 2 and Layer 3

A network consists of several layers that work together in order to process, route, and connect data packets. Essentially, these layers and switches allow us to transfer information from a source to a given destination with ease.

Let’s take a closer look at what you need to know about layer 2 and layer 3.

Layer 2 is known as the Data Link, and it is primarily involved in transmitting data from one specific node to another. Layer 2 can communicate within a network only, and it has a single broadcast domain. These nodes are usually directly connected, whether that’s via LAN, WAN or MAN. Two sublayers exist here, Medium Access Control (MAC) and Logical Link Control (LLC), which is where confusion can set in. It is important to understand that each protocol implements it’s lower layers
differently. We refer to data at this layer, as a “frame”. Frames have basic data in them such as a source address and a destination address. That basic data is often referred to as a header, a type of metadata. The protocol & Relay; gets it’s name from operating at this layer.

Layer 3 is known as the network layer. This is the one most people have heard of. Layer 3 can communicate within or outside a network. It has multiple broadcast domains. Layer 3 is responsible for creating paths (or circuits) that are used to transmit data from one node to the next. This layer offers routing, switching, and forwarding technologies, as well as packet sequencing. Layer 3 operations are responsible for receiving data frames from layer 2 and delivering that data to where it’s supposed to go. This is done using IP addresses and other information. So a Layer 3 switch is able to do everything a Layer 2 switch can, plus a lot more. Simply put, these two layers perform different functions but support one another in the pursuit of your ultimate connection goal.

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