What is the difference between Cisco core switches and access switches?

When you’re designing a large network, you’re going to need multiple different switches, and in many cases, those switches won’t serve the same role. As the demand on a network rises, you can’t just add more switches ad hoc.

Instead, you need to layer your switches correctly. For major networks, the traditional design is to have core switches, distribution switches, and access switches. Today, we’re going to focus particularly on core and access switches, discussing their primary differences and everything you need to know to figure out which kinds of switches should go where in a network.

What Is a Cisco Core Switch?

A core switch is a high-capacity switch that serves as the gateway to a wide area network (WAN). In this case, the word “core” is referring to the switch’s position in the networking infrastructure. It's part of the physical core of the network, also known as the backbone of the switching infrastructure.

In other words, it’s at the base level, and the rest of the network routes to and through the core layer. A core can have multiple switches, but core switches are managing all of the network traffic.

Because of this, core switches focus on bandwidth, redundancy, and security. If a core switch fails on any of these points, many users will be affected downstream.

What Is a Cisco Access switch?

A Cisco access switch is located at the access layer. This is commonly referred to as Layer 3 in networking lingo, and it’s the layer where endpoint devices connect to the network. As an example, if you have a networked security camera, it will need to connect to a switch to access the network. The switch connecting directly with the camera is an access switch.

Access switches communicate with wireless routers, personal computers, mobile devices, IoT nodes, and a whole lot more. The point here is that these switches allow those endpoint devices to communicate with the greater network.

Because of this function, access switches tend to focus on easy management and fast and easy deployment and device swapping.

What Are the Key Differences Between the Two?

Because the switches serve different roles in a network, they have important design focuses. Technically speaking, any aspect of design could overlap between a core switch and an access switch. They are ultimately connecting devices to a unified network, but their differing roles lead to very different design philosophies, and that is reflected in how they are made, their specifications, and how they are used in a network.

For the most part, all of these distinctions boil down to data rates and connected devices.

Demand and Data Rates

There are a whole lot more devices connected downstream of a core switch than an access switch. Because of this, the core switch has to provide much more bandwidth in order to support all of those devices.

It’s common for access switches to use copper ports. They might get up into the gigabit range for individual ports, and in some cases, you might even have 10 Gb ports, but in many cases, access switches are still offering 10/100 data rates to a lot of endpoint devices.

Meanwhile, core switches start in the gigabit range and go up quickly. Core switches are typically fiber optic devices, and it’s not uncommon to see them support rates up to 100G.

Ports and Access

Even though core switches are supporting more devices, they often have fewer ports. There are a few reasons for that. First, fiber optic connections are more expensive, so cutting the number of ports can lower the cost of a core switch.

But, that’s only possible because core switches don’t have to directly connect to very many devices. Instead, they’re connecting to other switches, each of which can connect to even more devices. As a result, a handful of ports is usually enough for a core switch.

Meanwhile, access switches often need a larger number of ports, and this is where you will find switches with 48 or more ports — allowing for large numbers of endpoint devices to connect to the network.

That about covers the primary differences between these two kinds of switches. Cisco makes a large number of both types, so you’ll find plenty of viable options in various price ranges and with all kinds of specifications.

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