Layer 3 Switch VS Router – Comparison

Layer 3 Switch and Router are both popular terms in the networking world. They get passed around a lot. As commonly as you might hear, you might not exactly understand what they are and the similarities between them. Since both of these support the same routing protocols, they can easily get confused with each other. This article will explain to you in detail what a layer 3 switch and what a router is. We will also see a Layer 3 Switch vs. router comparison and figure out their differences and properties. 

Layer 3 Switch VS Router

In basic terms, the layer 3 switch forms a local area network (LAN) by connecting hosts. A router connects two or more LANs to create wide area networks (LANs). These definitions might need more explanation for complete understanding, so let us look at layer 3 switch and router in detail. 

What Is A Layer 3 Switch

Layer 3 switch is a device that uses layer 3 information to forward traffic. They are sometimes also called ‘multilayer switches’. Layer 3 supports all switching features but it works with some fundamental routing functions. They are essentially used for large LANs since they help improve network routing performance. Layer 3 switches can perform layer forwarding faster than routers. 

They also do not experience latency issues as much as routers do and are faster than routers as well. Although layer 3 switches do not have the same advanced features as routers can not replace them. 

Layer 3 Switches do not support the WIC card. They are also unable to navigate through advanced routing features. However, they do have LAN capabilities and RMON support. 

What Is A Router

Router helps link your devices as home to a wifi network. A router can connect to multiple devices at once. Routers use layer 3 information to forward traffic using IP addresses. Routers also help protect networks from attacks. A router works through the layer 3 analysis of every packet and then routes it to its destination. The router takes a little time to decide the goal of the packets, and hence there is a little bit of delay. 

Routers support WIC Cards as well as can perform advanced routing features. They do not have LAN capability or support RMON, unlike layer 3 switches. 

Differences Between Layer 3 Switches And Routers

Let us now look at the differences between layer 3 switches and routers. 

Working Principle

Layer 3 sends the frame to the recipient based on the host’s MAC address. At the same time, the router works with an IP address and not the MAC address. 

Hardware

The hardware of layer 3 switches is a balance of the hardware of routers and conventional switches. Layer 3 switches do not have any WAN ports and hence it is mainly used to support VLAN routes. Routers do have WAN ports as well as additional features.

Interfaces

Routers have more interface options as compared to layer 3 switches. Some of the interface routers supported are SDH, SONET, E1/T1 etc. And some of the interface layer 3 switches have included Ethernet for RJ45 and single-mode/multimode fiber. 

Physical Scope

Layer 3 switches are used to provide LAN for offices, campus, or data centers, whereas Routers can serve the same environments, but they provide WAN. 

Forwarding Decision

In layer 3 switches, there are specialized ASICs to perform the forwarding of decisions. In the case of routers, the same function is performed by in-built software. 

Edge Technologies Support

Although layer 3 switches do not support edge technologies, routers support NAT, firewalling, tunneling, IPSec etc. 

Usual Size Of The Routing Table

Layer 3 switches do not require big routing tables. On the other hand, Routers might need a more oversized routing table to support more than two route entries. 

Policy Performance

Usually, layer 3 switches have high policy performance, but in the router case, it is significantly low. 

Throughput And Switching Capacity

Layer 3 switches have high throughput as well as high switching capacity. Whereas routers have throughput and switching capacity, both considerably lower than those of layer 3 switches. 

Cost And Port Density

Routers are costlier than layer 3 switches. When it comes to port density, layer 3 switches have higher port density than routers. 

Layer 3 Switch Or Router: Which One To Use?

Having gone through the fundamentals of layer 3 switches and routers, you might wonder which one is most suitable for you or what scenarios they are used in. Your choice between the two depends on your motive and networking structure. Here are some ways to use layer 3 switches and routers effectively to give you a better idea. 

Where can you use a layer 3 switch?

In case you need more throughput, a layer 3 switch is the best option. It also provides direct access and inter-VLAN communication. You can also use layer 3 switches for a network with multiple broadcasts in the requirement of better VLAN performance. 

Where can you use a router?

It would be best to use a router to connect an ISP directly to provide internet. You will also use a router if you are participating in MPLS configuration as a CE. A router is also a secure way to connect two workplaces over the public internet. 

To Sum It Up

This article helps you understand the basic working of layer 3 switches and routers and their differences. Which one among the two is most suitable for you depends on your business and networking environment and requirement. You can take help from the different uses of layer 3 switches and routers in the article.

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