What Is Distribution Switch and Why Do We Need It?

We know that in data centers a three-layer hierarchical model contains core layer, aggregation/distribution layer and access layer. In this network topology, corresponding network switch is implemented in different network layer. A core switch is a high-capacity backbone switch, which locates in the topside for WAN access and centralizing multiple aggregations in the core. Thus backbone core layer switch is often a fiber switch for advanced optical link. An access switch or an edge switch is for direct end devices and hierarchy connection. But what is distribution switch? What are the functions of distribution layer switch? And what’s the difference between aggregation switch vs core switch and distribution switch vs router? This article may help.

what is distribution switch and aggregation switch function

What Is Distribution Switch?

A distribution layer switch is a distribution layer switch, which uplinks to upper layer core switch and links down to the access/edge switch. Simply put, an aggregation switch in between functions a bridge between core layer switch and access layer switch. This is also the reason why we call distribution switch as aggregation switch.

Distribution Switch Functions

Why distribution layer switch is needed in network layers? In general, aggregation switch reacts on multiple switch aggregation and layer 3 routing functionality. It also supports complex policy implementation such as QoS and packet filtering. Highlights, distribution switch employs Access Control Lists (ACL) to offer optimized security policies. This security capability enables aggregation switch to decide which traffic can be permitted for communication. Here we illustrate the necessities of distribution layer switch into details by comparing it to other switches and routers.

  • Distribution Switch vs Access Switch

Usually we employ gigabit Ethernet switch in access layer 2 to run at 1Gb. When traffic driving from a layer 2 switch, the network topology requires a device with layer 3 features to process it to VLANs. Aggregation switch is often a layer 3 switch, so it supports inter-VLAN routing over a layer 2 switch. When multiple access switches among different VLANs are required to be aggregated, a distribution switch can achieve inter-VLAN communication.

  • Core Switch vs Distribution Switch

For core switch vs aggregation switch, one question may come in mind: why not directly connecting access switch to the core switch? An important reason is for convenient network access. When there are dozens of clients spreading over different offices in 5 buildings, we can deploy a distribution layer 10GbE switch in the center of each building to connect multiple access layer gigabit Ethernet switches in different offices. Then the 5 distribution switches can easily link to a 40GbE core switch in data centers. There are cases of combining collapsed distribution and core into one when there are only several severs and end users. We also call such switch as collapsed core or collapsed backbone since distribution layer switch is combined.

using fs 10GbE switch as distribution switch

Figure 1: Deploying FS S5800-48S6Q 10GbE switch with 6 40G QSFP+ uplinks as distribution switch in three-layer hierarchical model.

  • Distribution Switch vs Router

Generally, both a router and distribution layer switch has layer 3 routing functionality. But there is some distinctions. Compared to layer 3 switch/multilayer switch, a router has full layer 3 features and intact routing functionality like Internet Service Provider (ISP) and WAN. A aggregation switch combines layer 2 switching technology with layer 3 routing technology in one hardware. So a layer 3 distribution switch owns edges over router as switch while possessing inter-VLAN routing functionality. Besides, as a router a layer 3 distribution switch can route packets more quickly than a router due to functionality to make cache entry in its fast memory.

deploy layer 3 switch distribution switch over layer 2 switch and routers

Figure 2: Scenarios to deploy layer 3 switch – distribution switch over layer 2 switch and routers.

Conclusion

Despite advanced features of policy-based network connection, distribution layer switch functions aggregation and routing. As an aggregation switch, distribution switch connects multiple access switches and centralizes them to core switch. As a layer 3 switch, distribution switch adds routing functionality to achieve fast and easy inter-VLAN routing communication. As thus distribution switch deployment changes the situation that subnet must relay on router to manage network. And solves the issue of low speed and complexity caused by traditional routers.

What Is the Best Way to Connect Multiple Ethernet Switch?

In the big data era, gigabit Ethernet switch with high capacity has gradually penetrated from big enterprises, SMB to small offices and homes. Newly emerged technology like WIFI is also driving the proliferation of wireless APs and other applications. Therefore the Ethernet topology requires for a comprehensive integration of various devices like firewall, servers, routers and multiple Ethernet switches. How to connect multiple managed switches together? Can I simply connect network switch one by one? Does daisy-chaining switch make sense? Or should I stack switch with stackable switch to set up a switch stack? What’s the best method to connect several data switches together?

waht is the best way to connect multiple Ethernet switch

Solution 1: Cascade Switch to Connect Multiple Ethernet Switch

Switch cascade is a traditional way to connect multiple Ethernet switches, which comes with various methods and network topology under different requirements. Among them daisy chain topology and star topology are two common ways.

·Daisy Chain Topology – Daisy Chain Switch One by One

Daisy chain is a layout form to connect multiple Ethernet switches together in sequence or in a ring. A simple linear topology displays as A-B-C, in which you just daisy chain each network switch top to bottom. For no more than 3 Ethernet switches, a linear topology of daisy chaining is okay since there is no loop. However, it owns drawbacks in switch failure due to lacking redundancy. Once one network switch fails, the others will also be dragged in. A simple ring topology is A-B-C-A, which can provide redundancy in link failure. However, simultaneously a loop creates when you finally daisy chain switch C back to A. Thus even only daisy chaining 3 Ethernet switches, an inevitable loop can be a fatal weakness.

Simply put, daisy chaining switch is error-proof and easily causes unnecessary low performance issues. Besides loop, a bottleneck creates in the chain and speed will slow down when traffic passing through the second Ethernet switch (since the link is heavily utilized). So daisy chaining switch is not recommended if scheme is optional. For simple home use or low demand networks, daisy chaining switches can make sense. But make sure your network switch support STP to deal with the loop issue.

daisy chain topology vs star topology for connecting multiple Ethernet switch

Figure 1: An illustration of daisy chain topology vs star topology for connecting multiple Ethernet switches.

·Star Topology – Link Access Switches to the Core

Compared to daisy chain topology, a physical star topology by deploying a powerful core switch to connect multiple access switches with uplinks is an optimal solution. For instance, connecting each gigabit switch via 10G SFP+ uplink to a central 10GbE switch. Or connecting a powerful gigabit Ethernet switch to each edge switches. In this scenario no loop occurs and all access switch is much closer to the central switch data center. For redundancy concern, you can also double or triple uplink each access switch to the core switch.

core Ethernet switch star topology by S3800-24T4S

Figure 2: Deploying a powerful gigabit Ethernet switch S3800-24T4S as core switch to connect edge switches, which forms a simple star topology.

Solution 2: Use Stackable Switch to Connect Multiple Ethernet Switch

Daisy chaining switch can be a solution when Ethernet switch quantity is small and separate placement is required in low demanding applications. How about an optimized way to connect multiple switches? Here comes stackable switch. Stackable switch deploys advanced stacking technology to achieve switch stacking, leaving out performance issues of clumsy daisy chaining topology like loops and bottlenecks.

To stack switch with managed stackable Ethernet switch can set up a switch stack, which works as a unified system with one console port for control to enhance network scalability and simplify network management. The port density and performance of switch stack can equal to expensive rack mount switch. Say stackable 24 port gigabit managed switch with 4 10Gb SFP+ uplinks: S3800-24T4S 1000Base-T copper switch and S3800-24F4S SFP switch. Both Ethernet switch supports up to 4 24 port switches stacked together, providing 96 1GbE port density and switching a total capacity of up to 512 Gbps. Also with single and dual power supply available, this 24 port gigabit managed switch offers redundancy in emergent power outage. To stack up S3800-24T4S 24 port switches with 10G SFP+ ports, you should connect them via SFP+ modules with fiber patch cable or via DAC or AOC directly.

stack switch by S3800-24T4S stackable Ethernet switch

Figure 3: Deploying S3800-24T4S stackable 24 port gigabit switch to stack switch.

What Is the Best Way to Connect Multiple Ethernet Switch?

To cascade network switch by daisy chaining topology or star topology is a simple way to connect multiple network switch. Daisy chaining switch is not recommended due to aforesaid performance issues like loop and bottleneck. However, it does make sense when a powerful core switch is absent. Otherwise to connect gigabit Ethernet switch with 10G uplink to a core 10GbE switch is a better solution to go.

Using stackable switch to stack switch leaves out loop and other link issues. However, it only be feasible among same stackable switch model or stackable switch from the same vendor. Also, all Ethernet switches shall be stacked together, so it doesn’t support separate placement.

Table below compares the pros and cons for connecting multiple network switches by daisy chaining switch and stacking switch. You can refer to your own demand for selecting the best way.

Item Daisy Chain Switch Stack switch
Placement Separate Centralized
Link Distance Long/Short Short
Switch Types Various switches from different vendors Same stackable switch only
Link port Normal/Uplink port Stacking port
Operation & Control Separate As one single switch
Performance Problem-prone: Loop, bottleneck Advanced Features

Conclusion

Traditional cascading Ethernet switch (daisy-chain topology or star topology) and advanced stacking switch are two ways for connecting multiple network switches. When both stackable switch and a powerful core switch is unavailable, problem-prone daisy chaining switch makes sense for low demanding applications. Otherwise you can deploy a 10GbE switch or powerful gigabit switch as core to connect each edge switch for better performance. Stack switch by stackable managed switch, deploying stacking technology as built-in software to connect multiple Ethernet switch is a must for enterprise-level networks. It leaves out low loop issues and simplifies control mechanism.

48 Port Switch Buying Guide

As a core hardware device in data centers, network switch is vital for setting up a reliable network. Meanwhile 48 port switch with high port density has become popular among enterprise-class, small to midsize and even home users. However, how to buy an optimal 48 port switch for different network environment confuses many people. This article will make an analysis of 48 port switch for your buying guide.

What to Consider for Buying 48 Port Switch?

To buy an optimal 48 port switch for your network, one should take several factors into consideration. Above all, choose managed over unmanaged if possible. 48 port managed switch has advanced features in reliable performance, traffic control, custom management and security regulation. For modern applications requiring for high network privacy and resiliency, 48 port gigabit switch managed is a must. Besides, here lists other important factors for 48 port switch managed selection.

how to choose 48 port switch

·Capacity

What kind of virtualization applications are you implementing? Do they require extra high switching capacity? Generally 48 port switches in the market come with 2 different speed basis: 48 port gigabit switch and 48 port 10Gb switch. For average customers without special requirements 48 port gigabit switch can well meet their demands. But for speed pursuers 48 port 10Gb switch should be deployed for smooth operation in high traffic.

·Uplink Configuration

In addition to regular port, pay attention to the uplink port on 48 port switch. For multiple switch connection, 48 port gigabit switch often comes with several 10G SFP+ uplink ports whereas 10Gb switch comes with 40G QSFP+ or even 100G QSFP+ uplink ports for link aggregation. With a few corresponding uplink ports reserved, the 48 port gigabit switch can access to 10G core switch. And 48 port 10Gb switch can cater for future demands like next generation Metro, Dater Center and Enterprise networks.

·Power over Ethernet

For situations where power outlets are unavailable for cabling devices, 48 port PoE switch is a natural fit. A typical aforesaid case is for connecting Powered Devices (PD): IP cameras, VoIP phones and wireless access points (AP). By deploying 48 port PoE gigabit switch, you can easily put an IP surveillance camera anywhere on the ceiling.

What Are the Cheap 48 Port Switch Recommendations?

You can easily get the best 48 port switch with all advanced features once budget is not a concern. However, most people should note cost/performance ratio to get good but cheap 48 port switch. For good purchasing experience, here recommend you 2 best 48 port switch for reference.

·Cost-effective Non-PoE 48 Port Switch

Without PoE capability, here recommend S3800-48T4S 48 port switch managed. It comes with 48 10/100/1000Mb auto-sensing RJ45 ports and 4 10GE SFP+ uplinks for cost-effective gigabit access or 10G link aggregation. Thus you can easily deploy this 48 port Metro Ethernet switch either in access layer or as core switch. Also, with dual power available this 48 port gigabit switch managed provides redundancy in emergent outage.

FS 48 port switch application

Figure 1: Deploying FS S3800-48T4S 48 port gigabit switch as access switch and S1600-48T4S 48 port PoE switch for PDs in network layer.

·Cost-effective 48 Port PoE Switch

FS recommends S1600-48T4S 48 port PoE switch for both 600W high PoE power budget and reliable hardware with software integration. With 48 1000M RJ45 ports and 4 10G SFP+ uplinks compact in 1RU, this 48 port PoE gigabit switch owns high density and space saving features. As a 48 port gigabit switch managed, it supports both Web Interface and CLI command. Therefore it offers enterprise-class functionality of free configuration, strong security and reliable RSTP. As PoE+ switch, it complies IEEE802.3af/at standard. Thus the PoE network switch can auto figure which standard the PoE enabled device supports and then supply power to it. To deploy S1600-48T4S 48 port switch, you can flexibly put it in a rack, on a wall or on desktop. Power on the switch. Then connect over 40 APs or other PDs all over the building with only one each cable is required to run for them.

S1600-48T4S 48 port switch PoE

Figure 2: S1600-48T4S 48 port PoE switch connecting to VoIP phones, wireless APs and IP surveillance cameras for intelligent switching and networks growth.

Conclusion

Take a long-term view, 48 port switch with high port density provides abundant ports for your current devices and room for future network growth. Buying a best 48 port switch requires one to consider its own demands for specific applications. Based on which, one should take based speed, uplink port configuration, PoE capability and other personal requirement into consideration. For cheap 48 port gigabit switch, we recommend you classic one S3800-48T4S and 48 port PoE switch S1600-48T4S. For 48 port 10Gb switch, you can also find one with decent offer in FS.COM.

10Gb Switch Buying Guide

As the development of burgeoning network technology, gigabit network switch has become insufficient to meet the demand. In this circumstance, 10Gb switch, 40Gb switch and even 100Gb switch are designed to cater for current and future high capacity optical networks. Among them, 10GbE switch is the most popular one for both enterprise data center and carrier’s metro networks. This tutorial is a buying guide for 10Gb switch.

Overview of 10Gb Switch

Ever since 10 gigabit Ethernet has been defined by the IEEE 802.3ae standard in 2002, the ever-accelerated bandwidth intensive applications of 10G switches have been updating year by year. Typically 10gb network switch is used for interconnecting routers, servers in data centers to construct Spine-Leaf network. The reasons for boosting 10Gb switch deployments are never limited in the 10Gb speed providing. Moreover, 10GbE switch centralizes the pros of low latency, fewer bottlenecks, simple virtualized environment, spare bandwidth, rack space efficiency, low power consumption and expansion flexibility, etc.

FS 10Gb switch

Figure 1: FS S5850 & S5800 series 10Gb switches.

Concerns for Buying 10Gb Switch

When choosing  switch 10Gb, budget is always a big concern to obtain a cheap 10Gb switch. Generally speaking, more advanced 10GbE switches with managed or PoE features will be more expensive than the opposite one. Another factor first comes in our mind is number of port. For example, 12/24/32/48 port 10Gb network switches are all available at FS.COM. Table below shows the detail specification of FS S5800-48F4S 48 port SFP switch as an example for 10Gb switch.

Switching Class Layer2/3
Switching Capacity 176Gbps
Form Factor 1 RU
Latency 2.3us
Throughput 130.95Mpps
Max. Power Draw 75W
Hot-swappable Power Supplies 2 (1+1 redundancy)
Hot-swappable Fans 4 (N+1 redundancy)
CPU Cavium CN5010-500BG564-CP-G/500MHz

In addition to cost and port quantity, there are other factors to concern for buying 10Gb switch. Take a second for figuring out your network requirement and grasping the knowledge basis of 10GbE switch will save you budget and provide you superior buying experience.

·Managed Switch or Unmanaged Switch

Managed 10Gb switch is an advanced one for optimized network performance, which is best suitable for heavy-workload organizations requiring for traffic control, custom management and security monitoring. Unmanaged switch 10Gb is a configuration fixed plug-and-play switch. No customized management and control are supported for operators. Unmanaged switch 10Gb is best fit for anyone who just want to simply set up a network and let it run automatically. It is noted that smart partly-managed 10G switch is a compromise solution for both functional and cost-effective concerns.

·PoE Switch or Non-PoE Switch

PoE 10Gb switch deploys a single cable as medium for both data transmission and power supply to PDs, such as Wireless access points, IP cameras and VoIP phones. Breaking the tether of power outlet, it can be easily placed anywhere, on desktop, on a wall or mounted in a rack. But if power supply is not a question, you can just pick up non-PoE 10GbE switch, which will save your expense.

·Stackable Switch or Standalone Switch

Network upgrade and expansion are common in data centers, in this case, more switches are required for connecting the growing number of devices. When deploying standalone 10Gb switch, operators need to control each switch individually. Also, it is a complicated process to add new switch. Thus standalone 10Gb network switch is commonly used in small business networks. For larger enterprises, stackable 10G switch is dispensable to simplify the management and increase the availability of the network.

Ending

10GbE switch speeds your network up and provides high reliability and flexibility to your data centers. How to choose a cheap 10Gb switch? Try to take a second for making clear the following question: What is my budget limit? How is my network environment? How many ports are in need on the 10Gb switch? Is a managed switch 10Gb or PoE switch necessary? Should I deploy a stackable switch for future-proof concern? For buying gigabit switch, 10Gb network switch,  40Gb switch, or even 100G switch, FS is always a reliable vendor to go.

Related article: Recommendations for Cheap 48-Port 10Gb Switches