For businesses that rely on PoE devices to connect large and complex networks, a layer 3 switch may be the right solution. Also called a multilayer switch, a PoE layer 3 switch can route high-speed traffic between different networks such as multiple Virtual Local Area Networks (VLANs) or main networks and their branch offices.

Let’s discuss what PoE layer 3 switches are and look at their benefits.

What is Power over Ethernet (PoE)?

PoE is the technology that allows devices to receive both power and data from a single source. By eliminating the need for separate power cables, it saves time and money and allows for the installation of devices in hard-to-wire locations. PoE can be used to power wireless access points, IP cameras, VOIP phones, and building management devices like sensors and access control systems.

What are the OSI Layers in IT Networking?

Open Systems Interconnection (OSI) is a standard model of how applications communicate over a network. This model separates the communication process into seven different layers each with its own specific function.

The seven OSI model layers in IT networking are:

  1. Physical – The physical layer is responsible for transmitting data over a network. It defines the mechanical and electrical specifications, such as fiber optic cable or Ethernet cable, for how data is transmitted over a physical medium. (Fiber, Coax, Wireless, Repeaters, Hubs)
  2. Data-Link – The data-link layer detects and corrects data that is transmitted over the physical layer. It defines how frames are formatted and transmitted over a network. (Ethernet, Switch, PPP, Bridge)
  3. Network – The network layer routes data packets between different networks. Using routing protocol, it determines the best path for data to travel between two hosts. (IP, IGMP, ICMP, IPSec)
  4. Transport – The transport layer is tasked with providing reliable data delivery between two hosts. Using transport protocol, it ensures that data is not lost or corrupted during transmission. (UDP, TCP)
  5. Session – A session is a logical connection between hosts that allows them to communicate with each other. The session layer establishes and manages these sessions. (Sockets, Winsock, APIs)
  6. Presentation – The presentation layer formats data from one format to another, such as ASCII to Unicode, so that it can be understood by the application layer. (SSL, IMAP, MPEG, JPEG, FTP, SSH)
  7. Application – The application layer provides services to the user, such as file transfer, web browsing, and email. It is the only layer that interacts with the user. (HTTP, SSH, DNS, FTP, IRC)

Beginning with the physical cabling and continuing all the way to the application that is trying to communicate with other devices on a network, the OSI model gives a visual design of how the seven communication layers are built on top of one another. The model can be used for troubleshooting network problems as well as designing new networks. 

What is a PoE Layer 3 Switch?

Network switches connect devices like computers, printers, and wireless access points within a network to each other. Switches allow these devices to talk to each other by exchanging data packets. 

Having a lot in common with a traditional router in terms of appearance and function, a layer 3 switch supports the same routing protocols as it inspects incoming packets. It makes the same routing decisions that routers do while performing switching duties. Layer 3 switches can be configured to support Routing Information Protocol (RIP), Open Shortest Path First (OSPF), and Enhanced Interior Gateway Routing Protocol (EIGRP).

Layer 3 switches work on both OSI data-link and network layers. 

How is a Layer 3 Switch Different from a Layer 2 Switch?

A layer 2 switch works on the data-link layer using network device Media Access Control (MAC) addresses to determine where to forward frames. It uses both switches and bridges to break up a large collision domain into multiple smaller ones. Layer 2 switches will learn the MAC address of the device that receives the frame and forward it there. Using Spanning Tree Protocol (STP) or Multiple Spanning Tree Protocol (MSTP) to avoid looping, it splits a complicated LAN into small VLANS. 

XGS-6311-12X Multiple Spanning Tree Protocol

A layer 3 switch can do everything a layer 2 switch does, but it has both static and dynamic routing functions. That means it combines the functionality of both a switch and a router. Layer 3 switches inspect incoming packets to make routing decisions based on source and destination addresses. While a layer 2 switch works with MAC address only, a layer 3 switch routes packages using IP address. 

Layer 3 switches are slower than layer 2 switches, but they can communicate within or outside a network. Layer 2 switches communicate within a network only.   

What are the Benefits of a PoE Layer 3 Switch?

PoE layer 3 switches have many benefits for extensive, busy networks.

  • Reduces the volume of broadcast traffic
  • Streamlines security management
  • Supports routing between VLANs
  • Separates routing tables to better separate traffic
  • Lowers network latency because a packet does not have to make extra hops to go through a router
  • Enhances fault isolation
  • Eases the configuration process for VLANs
  • Supports flow accounting and high-speed scalability

A layer 3 switch is a powerful and versatile networking device that gives multiple options to manage bandwidth effectively.XGS-6311-12X Layer 3 10G SFP+ Switch

Why Choose a PoE Layer 3 Switch for Your Business

If you have VLANs in your network, plan to incorporate them in the near future, or have more than 250 devices connected to the same VLAN, a layer 3 switch might be right for your business. If individual departments within your organization require separate broadcast domains for performance and security, a PoE layer 3 switch can be beneficial.

Layer 3 switches can support multiple routing protocols to fit your network needs. Offering the ability to create complex routing configurations, they help to optimize network performance. PoE layer 3 switches can also support advanced features such as traffic shaping and quality of service (QoS).