Layer 2 or Layer 3 Switch: How to Choose for VLAN?

With the advent of VLAN (Virtual Local Area Network), network managers can logically divide the physical LAN into different broadcast domains by spanning across multiple switches or even routers. The first series of VLAN switches on the market are Layer 2 switches which operate at Layer 2 of the ISO Reference Model. Soon afterwards, Layer 3 switches emerge as alternatives for VLAN and have gained incremental popularity. Layer 2 vs Layer 3 switch, which is more suitable for VLAN? We’re gonna elaborate it in this post.

VLAN

Layer 2 Switch—Switching Layer for OSI Model

A Layer 2 switch is a type of network switch or device that works on the data link layer via OSI (Open Systems Interconnection) model and utilizes MAC address to determine the path through which the frames are to be forwarded. It uses hardware based switching techniques to connect and transmit data in VLAN. By looking at the destination MAC address in the frame header, the Layer 2 switch interconnects multiple end nodes of VLAN and intelligently forwards traffic between them without unnecessary flooding of frames onto the network. Generally speaking, Layer 2 switches come with different types of interfaces like 10 Mbps, 100 Mbps, 1 Gbps, 10 Gbps, etc. They can support full-duplex communication on each of its port. They expand network by connecting to the rest of the devices in the fabric through high speed ports that can be connected to either another Layer 2 or Layer 3 switch.

Pros and Cons

Pros

  • Forwards packets based on the unique Media Access Control (MAC) address of each end station
  • Information is easily retrieved and data packets transferred quickly at the wire speed of the network
  • No setup or management is required
  • Cheap and easy to deploy
  • Improve security with low latency
  • Flow accounting capabilities

Cons

  • Can not apply any intelligence when forwarding packets
  • Unable to route packets based on IP address
  • Can not guarantee bandwidth to Voice over IP (VoIP) users

Layer 3 Switch—Routing Layer for Sub Network

Layer 3 switch, known as the routing layer, can provide logical partitioning of sub networks with scalability, security, and Quality of Service (QoS). As an enhancement feature, QoS goes beyond the simple packet prioritization found in CoS by providing bandwidth reservation and packet delay bounding. In Layer 3 system, the packets are sent to a specific next-hop IP address, based on destination IP address. Different from MAC addresses of Layer 2 switch, each IP packet in Layer 3 switch contains source and destination IP addresses. The backbone of the Internet, along with those of many large organizations, is built upon a Layer 3 foundation. The functions of a Layer 3 switch (or multilayer switch) combine some features of a Layer 2 switch and a router.

Pros and Cons

Pros

  • Use logical addressing to determine the paths to destination networks
  • Intelligent packet forwarding (routing) based on Layer 3
  • Enable a router to link different sub networks together
  • Segment a network into two or more VLANs
  • Enhance security controls to prevent unauthorized setup changes
  • Provide guaranteed Quality of Service (QoS)

Cons

  • Extra processing power and memory is required for Layer 3 switching
  • Prices are higher than for a Layer 2 switch
  • Require setup and management

Layer 2 or Layer 3 Switch: How to Choose for VLAN?

Small networks can be built using just Layer 2 devices, but most corporate networks contain a mix of Layer 2 and Layer 3 switches as illustrated in the figure below. The most significant difference between Layer 2 and Layer 3 switch is the routing method. Layer 3 switch is capable of inter-VLAN routing and does not need additional device connected like router on-a-stick. Since network architectures on Layer 2 switching allow end station connectivity, it is often practical to construct a VLAN via Layer 2 switch only. Because it can provide simple, inexpensive, high-performance connectivity for hundreds or even thousands of end stations. However, Layer 3 switches also maintained a presence at many points within a corporate network. For a while it presents minimal problems, since a majority of the data traffic stayed local to the sub network, which was increasingly being serviced by a Layer 3 switch.

layer 2 vs layer 3 switch for VLAN

Summary

Both Layer 2 and Layer 3 switch have seen the most striking infrastructure for VLAN over the past decade. Whether to choose a Layer 2 or Layer 3 switch is dependent upon many factors, such as routing method, speed requirement, networking design, as well as your budge. But where to get reliable and high performance Layer 2 and Layer 3 network switch? FS.COM provides a full set of gigabit switch, 10gb switch, 40gb switch and 100gb switch with Layer 2 or Layer 3 feature, which can support advanced hardware based VLAN deployment.

Related Article: Layer 2 vs Layer 3 Switch: Which One Do You Need?

Deploying 10G ToR/Leaf Switch for Different Size Networks

With the migration from Gigabit Ethernet to 10 Gigabit Ethernet, cabling and network switching architectures have been reevaluated to guarantee a cost-effective and smooth transition. 10Gb ToR (Top of Rack) or leaf switch has evolved with significant performance gains and cost-per-port reduction. This post will introduce the benefits of ToR architecture and explains how to deploy 10G ToR/leaf switch for different size networks.

Why Use Top-of-Rack Architecture

ToR or leaf-spine is a network architecture design where there are only two tiers of switches between the servers and the core network. In ToR network design, a feature-rich 10GbE switch handles Layer2 and Layer3 processing, data bridging and Fibre Channel over Ethernet (FCoE) for an entire rack of servers. This approach contributes to an agile infrastructure because the ToR/leaf switches can support multiple I/O interfaces, including GbE, 10GbE and 40GbE. The 10G ToR/leaf switches utilized in the ToR architecture usually come with the advantage of low power consumption, ease of scale and simplified cabling complexity. When acting as a ToR/leaf switch, each 10G Ethernet switch can be placed just one hop away from another, no need to jump up and down in the tree design, enabling improved latency and bottlenecks. With a ToR design, you can eliminate cabling nightmares, minimize bottlenecks while building a network foundation for mission-critical applications that also provides a clear path for future growth.

Top of Rack Architecture

Campus Network Applications

For campus networks applications, the 10GE switches work as aggregation or core switches in the ToR network architecture. Here we take FS S5850-48S6Q 10G ToR/leaf switch as an example to illustrate how to build a ToR network in campus networks. In the following application diagram, two FS S5850-48S6Q 10GE switches are utilized as aggregation switches as the bridge to build connections between 40G switches in the core network and gigabit switches in the access layer.

10G ToR Switch Campus Network Application

SMB (Small and Medium-Sized Business) Applications

For small and medium-sized businesses, ToR network architectures are becoming more preferable by IT managers than ever before. Because ToR architectures enable them to implement a single cabling model that can support Gigabit Ethernet and 10 Gigabit Ethernet and unified network fabric today, while supporting future 40 and 100 Gigabit Ethernet standards as they come to market. Using ToR architecture for fiber cable management, business IT managers have the flexibility to deploy preconfigured racks with different connectivity requirements in any rack position. For example, a rack of servers running multiple Gigabit Ethernet connections can be placed next to a rack of servers with 10 Gigabit Ethernet and FCoE connections to each server.

Data Center Applications

In hyper-scale data centers, there might be hundreds or thousands of servers that are connected to a network. In this case, ToR/leaf switches work in conjunction with spine switches in data centers to aggregate traffic from server nodes and then connect to the core of the network. Now given that we need to build a data center fabric with a primary goal of having at least 480 10G servers in the fabric. In this case, we can use FS S8050-20Q4C as spine switch and S5850-32S2Q as ToR/leaf switch. As shown in the figure below, the connections between spine switches (FS S8050-20Q4C) and ToR/leaf switches (FS S5850-32S2Q) are 40G, while connections between the leaf switches and servers are 10G. The port numbers on each spine switch determines the number of leaf switches we can use. But the maximum amount of 10G servers we can connect to ToR/leaf switch here is 24 because the ratio of reasonable bandwidth between leaf and spine switch cannot exceed 3:1. Thus the total amount of bandwidths we can get here is 480x10G.

10G ToR Switch Data Center Application

Top-of-Rack Cabling Recommendations

ToR network architectures utilize available cabling media options with flexibility at the rack level, using various server patch cable types, while taking advantage of fiber uplinks from the rack for horizontal cabling. Investment in the cabling media for 10, 40, and 100 Gigabit Ethernet connectivity involves striking a balance among bandwidth, flexibility, and scalability. Although both fiber and copper can support 10G, 40G and 100G transmission, fiber is the recommended horizontal cabling media as it offers an optimal solution for high speed 40G and 100G transmission over relatively long distances. Note that 40G and 100G transmission calls for multiple fiber strands (OM3, OM4, and SMF fiber).

Conclusion

The choice of ToR networking architecture can substantially affect throughput, sustainability, optimum density and energy management. As the key element of building ToR networks, 10G ToR/leaf switch can help you scale up networking architecture while delivering low-latency and high-bandwidth links. FS S5850/N5850 series switches are high performance 10GbE ToR/leaf switches which can work with Broadcom, Cisco, Juniper, Arista switches, as well as other major brands. For more information about 10GbE ToR/leaf switches, please kindly visit www.fs.com.

Related Article: 10G ToR/Leaf Ethernet Switch: What Is the Right Choice?

Ethernet Switches: to Stack or Not to Stack?

Over past years, stacking has escalated from a premium feature to a core constituent of an Ethernet switch. When it comes to network design, you may often face two challenges: maximizing scalability and optimizing performance. Finding the right balance can be tricky. This is why you’ve considered stacking or not stacking when managing your Ethernet switches.

What Is Switch Stacking or Stackable Switches?

Stackable switches or stacking switches are a type of switch designed to be stacked on top of one another. Stackable Ethernet switch is now well established as a stable, standards-based connectivity technology to efficiently handle and manage bandwidth-hungry applications. Stacking allows you to manage multiple switches as a single entity and provides increased bandwidth between the switches. Stackable switches can be placed in networking closets and stand alone as a whole unit. The feature sets of stackable switches vary depending on vendor and platform. Most stackable switches support advanced functions like QoS, multicasting, and VLAN management. For instance, the following FS S3800-24T4S stackable switch is a 24-Port 10/100/1000BASE-T Gigabit switch with QoS flow control and IP subnet-based VLAN. It supports up to 4 switches stacking and up to 96 Gigabit ports and 8 10G SFP+ ports per physical stack, providing up to 512Gbps total switching capacity for the network.

stackable switch

To Stack or Not to Stack – Think Twice Before Buying

Whether an enterprise outfits its wiring closets with stackable switches or not will depend on what services are needed and how much redundancy is required at the network edge. Stacking multiple switches allows for efficiency and ease of management when you do it right. The switch capacity of a stack is the total port density of the combined switches that are stacked together. For example, when you stack four 24-port switches, you will get one large 96-port switch when it comes to configuration. All these switches in the stack share a single IP address for remote administration instead of each stack unit having its own IP address.

In a small business where access to data and resources are critical, it is a wise option to choose stackable switches because they can significantly reduce downtime and make your network more resilient. In mission critical networks, if a switch within the stack went down, another switch would take over, ensuring that your network remains up and running uninterruptedly. In this way, stackable switches provide additional protection and redundancy for your network. Moreover, you can replace the breakdown switch in the stack without having your network offline for extended periods and impacting employee productivity in the process.

Approaches to Stack Ethernet Switches

Generally, there are mainly two ways to stack multiple network switches into a group. For stackable switches with dedicated stacking ports, a stack cable is used to realize switch stacking among them. But only approved cable can be used as stack cable, or else it would cause damage to the switches. The other approach is to use the uplink ports on the switch to connect each switch together in the stacking system. Most stackable switches on the market today can be stacked using several types of Ethernet ports including 10GBASE-T copper port, 10G SFP+ fiber port and 40G QSFP+ port as an uplink. For example, FS S3800-24F4S stackable managed switch uses 4 10G SFP+ ports as uplink ports to stack between switches. Up to four of the same type of models can be stacked together via SFP+ transceivers (with fiber patch cable) or DAC cables. Here’s the video to show you how to stack FS S3800 series switches step by step.

FS.COM Stackable Managed Switch List

Model Switch Class Switching Capacity Gigabit RJ45 Ports SFP Ports SFP+ Ports Combo Ports Price
S3800-24T4S Layer2+ 128Gbps 24 N/A 4 N/A US$369
S3800-24F4S Layer2+ 128Gbps N/A 20 4 4 US$389
S5900-24S Layer3 480Gbps N/A N/A 24 N/A US$1999

Note: Please be careful about Ethernet switches in the market which are sold as “stackable” when they merely offer a single user interface, or central management interface, for getting to each individual switch unit. This approach is not stackable, but really “clustering”. You still have to configure every feature such as ACLs, QoS, Port mirroring, etc, individually on each switch.

Conclusion

As your business grows, is your network prepared to grow accordingly? Stackable switches have become extremely popular for good reasons. They can simplify management and enhance switching capacity for easy network expansion. But for most customers, achieving super high availability may not be the goal. Then standalone switches are already enough for you rather than stackable switches. Thus the pay-as-you-grow stackable switch model is suitable for those who need flexibility, not only in their physical network, but also in the amount of traffic that is going through it.

Related Article: FS S5900-24S Stackable Switch: Affordable Option for Network Expansion

What Is Gigabit Switch

Nowadays, smart home and home automation are becoming more widespread. Small and medium enterprises have been developing vigorously. All of these phenomenons greatly promote the usage of Gigabit switch. For network engineers, Gigabit switch is an essential component in their network construction and can be an inexpensive and easy way to expand network in home and small business. This article is mainly conducted to popularize the generic concept and different types of Gigabit switch so as to help choose a suitable one for your networking.

Gigabit Switch

Concept of Gigabit Switch

In computer networking, a Gigabit Ethernet switch connects multiple devices, such as computers, servers, or game systems to a Local Area Network (LAN). It also empowers devices like 4K HDTVs and DVRs to connect directly to the internet without depending on Wi-Fi. With the ability of speeding up data transfer, it results in faster response time and better frame rate. In general, a Gigabit Ethernet switch expands network capacity via extra ports.

Types of Gigabit Switch

There are many different types of switches in the market. According to the quantity of devices you have and the people who use the network, you need to choose relevant switch. If you want to expand your network without big expense, the basic Gigabit Ethernet switch is a great choice for small and medium environments to boost performance and efficiency of network, such as 16-port and 24-port Gigabit switch. For home users, a 8-port Gigabit switch is enough. Here, we just introduce the basic concept of managed and unmanaged switch, PoE switch and stackable switch to help distinguish the functions of different types of Gigabit Ethernet switch.

  • Unmanaged Switch

Unmanaged switch is regularly used in home networking, small companies and businesses. A basic unmanaged gigabit Ethernet switch has no user configuration. So it is simple to set up. If you want to add more Ethernet ports, you can use these plug and play types of switches in your networking.

  • Managed Switch

Comparing to unmanaged switch, the primary advantage of managed switch is that it can be customized to enhance the functionality of a certain network. It can also be monitored and adjusted in some aspects. It adjusts speeds, monitors traffic and report network activity. Although a managed switch is typically more expensive than an unmanaged switch, it offers greater flexibility.

  • PoE Switch

PoE Gigabit switch is a network switch which applies Power over Ethernet technology. When connected with multiple network devices, PoE switch can support power and data transmission over one network cable at the same time. It will extremely simplify the cabling process.

PoE Gigabit switch

  • Stackable Switch

A stackable switch is a network switch that is fully functional operating standalone. But it can also be set up to operate together with one or more network switches. Since it can be configured, the stack of switch will automatically reroute in case of a port or cable failure.

Conclusion

This article concisely introduces four types of switches in networking: unmanaged switch, managed switch, PoE switch and stackable switch. When Gigabit switch is in an selection, the number of users your network supports should be given the utmost attention to. Broadly speaking, for small families, a 8-port Gigabit switch is adequate. While for SMBs or large enterprises with many network devices, a 24-port Gigabit switch can be used in offices to connect desktops or laptops. On the contrary, a 24-port Gigabit switch with a better prospect is more applied in small business network. Quality and standards are the foundation of FS.COM, if you have any need, FS.COM will always be your best choice.

SFP Connector vs SFP+ Connector vs SFP28 Connector

SFP (Small Form-factor Pluggable) module connector with various data speed rate is one of the major optical transceivers used for data communication. With ever-increasing demand for faster speed and higher density, the SFP connectors have experienced several generations of update for the signal speed capability as well as port density, from the original SFP to SFP+ and then to the new SFP28 type. The compatibility of these connecting ports is the pain point for many subscribers in data communication transmission. So what’s the similarities and differences between them and are these module connectors compatible with each other when plugged into switches? SFP28 vs SFP+ vs SFP connector, which one should you choose? This paper will give you the answer.

What Is SFP Connector?

Specified by a multi-source agreement (MSA), SFP connector was first introduced in early 2000 and designed to replace the previous gigabit interface converter (GBIC) connector in fiber optic and Ethernet high-speed networking systems. Based on the IEEE 802.3, SFF-8472 protocol specification, SFP module connectors has the ability to handle up to 4.25Gb/s with greater port density than the GBIC, which is why SFP is also known as mini GBIC. This allowed it to quickly become the connector of choice for system administrators who liked the idea of being able to significantly increase their output per rack. The SFP connectors can support Gigabit Ethernet, Fibre Channel, Synchronous Optical Network (SONET) and other communication standards.

What Is SFP+ Connector?

To cater the need for faster transmission speed, the SFP+ (or SFP10) was introduced in 2006, as an extension of the SFP connector. Based on IEEE802.3ae, SFF-8431, and SFF-8432 protocol specifications, the SFP+ is designed to support data rates up to 10Gb/s. Compared with its predecessor SFP, the newly SFP+ can support Fibre Channel, 10GbE, SONET, OTN, and other communication standards. The SFP+ is similar in size to the SFP connector. And the primary difference between an SFP and a SFP+ is their transmission speed. It is noticeable that SFP/SFP+ are both copper and optical.

SFP Connector

SFP28 Connector–The Third Generation of SFP Connector

As the third generation of SFP interconnect systems, the SFP28 (Small Form-Factor Pluggable 28) is designed for 25G performance specified by the IEEE 802.3by. The SFP28 connector delivers increased bandwidth, superior impedance control with less crosstalk compared to the SFP10. SFP28 can be sorted into SFP28 SFP-25G-SR and SFP-25G-LR. The former is designed to transfer data over short distance (up to 100m over MMF) while the latter is suitable for long distance transmission (up to 10 km over SMF). Utilizing 25GbE SFP28 leads to a single-lane connection similar to existing 10GbE technology, however it can deliver 2.5 times more data, which enables network bandwidth to be cost-effectively scaled in support of next-generation server and storage solutions.

Are the SFP, SFP+ and SFP28 Products Backward Compatible?

In most cases the connector and cable assembly are all backward compatible – an SFP+ connector is a direct replacement for an SFP connector to ensure simple upgrade to customer systems. As these are standard products, the cable assembly will also be compatible between the systems – an SFP copper cable assembly can be inserted to an SFP+ cage and mate with a SFP+ connector on the board.

Then how about the new SFP28 product? Since transceivers with various SFP connector types have become an important constituent of data communication network, compatibility issue of SFP28 and SFP+ is controversial among many subscribers. Here is a typical topic from Reddit, and it says like “For a project we’re looking to purchase some nexus 93180YC-EX ToRs for 25Gb+ down to the compute nodes. Cisco states that the downlink 25Gb ports are also 10Gb capable, but one can only really assume that means that the port is compatible with SFP+ optics too. Cisco’s SFP+ compatibility matrix appears to support that claim, however just curious if any of you have any SFP28 experience yet to confirm?”

The answer is definitely “yes”. SFP28 adopts the same form factor as SFP+, just running at 25 Gb/s instead of 10Gb/s, which offers better performance and higher speed. Besides, the pinouts of SFP28 and SFP+ connectors are mating compatible. Therefore, SFP28 connector is backwards compatible with SFP+ ports. That is to say, an SFP28 can be plugged into an SFP+ port and vice versa, but plugging an SFP+ into an SFP28 port would not get you 25Gb/s data rates.

Conclusion

SFP28 vs SFP+ vs SFP connector? Have you made clear which one to choose? Whether choosing SFP or SFP+ depends on your switch types. If your switch port only supports 1G, you can only choose the 1000BASE SFP (eg.MGBSX1). If it is a 10G switch, it depends on the speed and distance you require. When choosing between SFP28 and SFP+, it all depends on the transmission data rates you need. The SFP28 aims to build 25GbE networks that enables equipment designers to significantly reduce the required number of switches and cables. Thus when considering reduced facility costs related to space, power and cooling, the SFP28 would be the optimal choice for you.