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An Overview of Layer 3 Switches

A Layer 3 switches plays an important role in many applications in today’s diverse enterprise networks that have many virtual LANs and subnets. Do you, though, want this on your network? Let’s see what happens.

What is the difference between a Layer 3 switches and a Layer 2 switches?
A Layer 3 switch, to put it simply, incorporates the functions of a switch and a router. It works as a link to quickly link devices on the same subnet or virtual LAN, and it also functions as a router thanks to its built-in IP routing knowledge. It will run routing protocols, examine incoming packets, and render routing decisions based on source and destination addresses. A Cisco Layer 3 switch often serves as both a switch and a router in this manner.

A Layer 3 switch, also known as a multi-layer switch, gives a network a lot of versatility.


ON THIS PAGE: An Overview of Layer 3 Switches


Difference Between Layer 2 Switch & Layer 3 Switch | Difference Between Layer 3 Switch & Router

Characteristics of a layer 3 switch

A Layer 3 transition has the following characteristics:

  • It has 24 Ethernet ports but no WAN link.
  • It connects computers on the same subnet by acting as a key.
  • The switching algorithm is straightforward and common to most routed protocols.
  • It works on layers 2 and 3 of the OSI model.

What is the aim of a Layer 3 switch?

Since routers run at Layer 3 of the OSI architecture, while switches operate at Layer 2, there is a lot of misunderstanding over utilising a Layer 3 switch. So, what role does this Layer 3 transition play in this model? The term “layer 3 switch” is often misleading since switches usually run at layer 2.

Layer 3 switches were created to help large networks, particularly corporate intranets, improve routing performance. Let’s take a look at how these switches evolved over time to better understand their purpose.

When there is low to medium traffic on VLANs, Layer 2 switches operate well. As traffic rose, though, these switches would get stuck. As a result, it became necessary to improve Layer 2’s functionality.

One choice was to use a router rather than a switch, but routers are slower than switches, so efficiency could suffer.

To get around this limitation, the researchers suggested putting a router within a switch. While physically possible, it was not the best option since Layer 2 switches only deal with the Ethernet MAC base, while Layer 3 switches deal with a variety of routing protocols. The researchers decided that this was too difficult, so they devised a Layer 3 switch that would serve as routers, with fast-forwarding handled by the underlying hardware.

As a result, the hardware differences between Layer 3 switches and routers are the most important. A Layer 3 switch’s hardware resembles that of conventional switches and routers, with the exception that the router device logic is substituted by integrated circuit hardware to increase efficiency.

A Layer 3 switch router would also lack WAN ports and other WAN functionality that a standard router will have.

VLAN figure using Switches and Routers
VLAN figure using Switches and Routers

The advantages of a Layer 3 transition

The purpose/benefits of a layer 3 update, as discussed above, are:

  • Support for routing across virtual LANs.
  • Improve the separation of faults.
  • Simplify defence administration.
  • Reduce the amount of broadcast traffic.
  • Since each VLAN does not need its own router, the setup procedure for VLANs is simplified.
  • Separate the routing tables and, as a result, traffic will be better separated.
  • It’s tedious and time-consuming to simplify troubleshooting, such as troubleshooting the L2 layer.
  • Flow accounting and high-speed scalability are supported.

Since a packet does not have to travel through a modem, it has the lowest network bandwidth.
Let’s look at the possible problems that come with a Layer 3 transition now that you know why your business wants one.

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Disadvantages to Layer 3 switches

A Layer 3 turn, like every other product, has flaws. We’ll go through each of these drawbacks quickly to help you make the best decision.


One of the most significant drawbacks of a Layer 3 switch is its cost. It is significantly more expensive than a standard switch, and configuring and handling these switches takes even more time. As a result, a company must be prepared to devote extra time to configuring Layer 3 switches.

Applicability is restricted.

Only wide intranet environments with several system and traffic subnets can use Layer 3 switches. This switches are unnecessary for homes and small businesses.

WAN connectivity is not accessible.

Another significant drawback of Layer 3 switches is their absence of WAN features. This ensures you won’t be able to do away from routers, because you’ll require both Layer 3 routers and switches to redirect traffic in and out of your network.

Virtualization with many tenants

Layer 3 routing is much slower than Layer 2 switching. When you try to distribute VLANs through numerous switches to accommodate multiple tenants and virtualization, this may be a challenge.

Flexibility is lacking.

The VLANs would be local to the same switch when you’re routing at the access layer. To put it another way, a VLAN would be connected with a single switch and would not be usable on all other switches. Because of this restriction, careful planning is needed to avoid a LAN utilising several switches.

Do you need it?

The major issue now is whether your network needs a Layer 3 turn. Ok, it depends on the scale and setup of your network.

In general, if you respond yes to either of the above queries, you’ll want a Layer 3 turn.

  • Is there a VLAN on your network? Do you want to have them in the near future?
  • Is it essential for specific divisions to have their own broadcast domains for protection and performance reasons?
  • Can you need a router to bind your subnets?
  • If you have more than 250 computers attached to the same VLAN on your network?
Switch | Types of switches | L2 and L3 switch | switch models explained |Free CCNA 200-301|


If you answered yes to any of the above questions, you will almost certainly benefit from a Layer 3 switch. It is voluntary in all other situations.

Switches and routers are both used by Layer 3 switches. They’re just good for VLAN and they don’t have a WAN gui. However, VLANs offer you a variety of choices for effectively using your bandwidth. This is why Layer 3 switches are both a reliable and flexible technology for constructing high-speed Ethernet networks.

Read More: Spanning Tree Protocol: STP in a nutsell. Configuration & Explained.


What is Layer 3 Switch? - Brief Introduction » NetworkUstad


How does it work?

Layer 3 switches operate on two distinct levels: layer 2 and layer 3. Their layer 3 switching capability comes in two flavors:

  • PPL3 (Packet-by-Packet) switches: These switches examine each packet in order to identify its logical layer 3 destination address (such as its destination IP address). PPL3 switches are basically high-speed routers with routing capabilities integrated into the hardware rather than software. Aside from forwarding a packet to its destination, these switches, like routers, perform additional tasks such as using the packet’s checksum to verify its integrity, updating the packet’s Time to Live (TTL) information after each hop, and processing any option information in the packet’s header. PPL3 switches usually interact with one another using a routing protocol such as Routing Information Protocol (RIP) or Open Shortest Path First (OSPF) Protocol to get knowledge of the network’s overall topology.
  • Switches with a cut-through: These switches examine just the first packet in a series to identify its logical layer 3 destination address (such as the destination IP address) and then switch the other packets in the series using the layer 2 address (MAC address). As a result, data throughput rates increase.
  • Layer 3 switches, in addition to executing layer 3 switching duties (routing functions), also execute Layer 2 switch functions (bridging functions) at each switch interface. Layer 3 switches are a strong, scalable technology for constructing high-speed Ethernet backbone networks because you can combine switching interfaces in different ways to distribute bandwidth and contain broadcasts.


The report on the Global Layer 3 Switch Market offers significant insights such as dominant drivers, prospective growth opportunities, constraints, challenges, and forecast to 2026. Porter’s Five Forces analysis, Competitiveness analysis, Assessment of Key Features, and geographical analysis are all used to this study. The Layer 3 Switch market study examines major categories, trends, and variables that are important in the Layer 3 Switch industry.

The most recent Layer 3 Switch market research report includes a thorough examination of the variables that will propel and stymie industry development in the future years. Furthermore, the study identifies opportunities across different regions and evaluates the risks associated with a robust realization of revenue generating potential throughout the projected period.

According to professional experts, the sector is expected to provide significant profits between 2021 and 2026, with a CAGR of XX percent throughout.

In terms of current updates, the study literature emphasizes the effect of Covid-19 and how it has altered the corporate environment, in addition to addressing the recent mergers, acquisitions, and collaborations of the major businesses. Although some companies have effectively adapted to the circumstances, many others continue to confront a variety of difficulties. In this regard, our comprehensive study of this market sector is well-equipped with numerous methods to assist companies in generating significant profits in the future years.

The following are the key characteristics of the Layer 3 Switch market report:

  • The effect of the COVID-19 pandemic on the growth matrix
  • Sales volume, net revenue, and market size are all reported.
  • Significant industrial trends
  • Opportunities for business expansion
  • Forecasted market growth rates
  • The advantages and disadvantages of using direct and indirect sales methods
  • Leading industry distributors, dealers, and traders

The following Layer 3 Switch market segments are addressed in the report:

Geographic divisions include North America, Europe, Asia-Pacific, South America, the Middle East, and Africa.

Market research at the national and regional levels
Each regional market contributed sales, returns, and market share.
Revenue and growth rate projections for each area during the given period

Product categories:

  • Software-based and hardware-based
  • Models of pricing for each product category
  • Predictions of market share based on sales and income generated by each product category

Spectrum of applications:


  • Gateways for residential and commercial use
  • Product price is determined by the scope of the application.
  • During the study period, each application category retained revenue and sales volume.

Dashboard of competitors:

  • Cisco
  • Huawei
  • The SOLIDEX Group
  • Moxa
  • Ruijie Networks is a networking company based in China.
  • Arista Networks is a networking company.
  • UTEK TECHNOLOGY and ORing Industrial Networking

Each company’s synopsis
The top contenders’ product and service offerings
Figures for each player’s sales, price, revenue, gross margin, and market share

Read More: Getting Started with Open Shortest Path First (OSPF)

SWOT analysis of the publicly traded businesses

An overview of market concentration, commercialization rate, and prominent business methods
The Report Provides Answers to Important Questions:

  • Which companies dominate the worldwide Layer 3 Switch market?
  • What will the worldwide Layer 3 Switch market size be in the future years?
  • Which market sector will dominate the worldwide Layer 3 Switch market?
  • What changes will occur in market development patterns during the next five years?
  • What is the competitive landscape of the worldwide Layer 3 Switch market like?
  • What are the primary tactics used in the worldwide Layer 3 Switch Industry?

Major Topics Covered in the Table of Contents:

Overview: In addition to providing a general overview of the Layer 3 Switch market, this part provides an overview of the report to provide an understanding of the type and contents of the research study.

Research of Leading Players’ Strategies: Market participants may utilize this analysis to get a competitive edge over their rivals in the Layer 3 Switch market.

Key Market Trends Analysis: This part of the research provides a more in-depth examination of the current and future trends in the Layer 3 Switch market.

Market Forecasts: Report purchasers will get access to precise and verified estimations of the overall market size in terms of value and volume. The research also includes estimates for consumption, manufacturing, sales, and other aspects of the Layer 3 Switch market.

Regional Growth Analysis: The study covers all important areas and nations. The regional analysis will assist market participants in entering untapped regional markets, developing particular strategies for target areas, and comparing the development of all regional markets.

Segmental Analysis: The research offers precise and trustworthy predictions of the market share of key Layer 3 Switch segments. This research may be used by industry players to make strategic investments in key growing areas of the Layer 3 Switch market.


Switching at Layer 3

A layer-3 switch may fulfill some or all of the tasks that a router would usually do. Most network switches, on the other hand, can only support a single kind of physical network, usually Ethernet, while a router can handle several types of physical networks on separate ports.

Layer-3 switching is entirely dependent on the (destination) IP address provided in the IP datagram header (layer-4 switching may use other information in the header). The way a layer-3 switch and a router make routing decisions is what distinguishes them.

Traditionally, routers utilize microprocessors to make software-based forwarding choices, while switches solely conduct hardware-based packet switching (by specialized ASIC with the help of content-addressable memory). [1][2] Many routers, however, now include sophisticated hardware features to help with forwarding.

The primary benefit of layer-3 switches is the possibility of reduced network latency since a packet may be routed without making additional network hops to a router. Connecting two different segments (e.g., VLANs) with a router to a typical layer-2 switch, for example, necessitates sending the frame to the switch (first L2 hop), then to the router (second L2 hop), where the packet inside the frame is routed (L3 hop), and then sent back to the switch (third L2 hop).

A layer-3 switch performs the same function as a router (and therefore eliminates the need for extra hops) by making the routing choice directly, i.e. the packet is routed to another subnet and switched to the target network port at the same time.

Because many layer-3 switches provide the same functionality as conventional routers, they may be employed in certain networks as lower-cost, lower-latency alternatives. Layer 3 switches can do the following tasks that routers can as well:

Paths are determined based on logical addressing checks, and layer-3 header checksums are recomputed.
Examine and update the time to live (TTL) field procedure, as well as react to any choice information \supdate Managers of the Simple Network Management Protocol (SNMP) with Management Information Base (MIB) data
The following are some of the advantages of layer 3 switching:

When compared to pure routers, rapid hardware-based packet forwarding with low latency has a cheaper per-port cost.

Service  Of quality (QoS)

IEEE has created hierarchical language that may be used to describe forwarding and switching operations. End systems (ESs, singular ES) are network devices that lack the capacity to forward packets across subnetworks, while intermediate systems (ISs) have these capabilities (ISs).

ISs are further classified as those that only communicate within their routing domain (intradomain IS) and those that communicate both inside and between routing domains (interdomain IS) (interdomains IS).

A routing domain is usually regarded as a section of an internetwork that is subject to common administrative authority and is governed by a certain set of administrative rules. Autonomous systems are another name for routing domains.

An knowledge of IP multicast through IGMP snooping is a typical layer-3 feature. With this knowledge, a layer-3 switch may improve efficiency by sending multicast group traffic only to ports where the connected device has indicated that it wishes to listen to that group.

IP routing between VLANs established on a Layer-3 switch is usually supported. Some layer-3 switches support the routing protocols used by routers to communicate route information across networks.

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