How to select a layer-3 Switch

Layer-3 switches are quite common, So I studied how to correctly select the layer-3 Switch. Here I will share it with you, hoping it will be useful to you. The current vswitches generally have the "routing" function, which makes it hard for many enterprise users to figure out whether a vswitch can be used instead of a vro. How can I select a vswitch?
　
In fact, the layer-3 switch is a layer-2 switch with the layer-3 routing function. Both the layer-3 switch and the router work on the layer-3 network and forward or exchange data packets based on IP addresses ), there is no big difference in principle. These two terms tend to be uniform. The so-called exchange router and route switch refer to the same thing. We can think that the layer-3 switch is a multi-port router.
　
With the rapid development of Internet and enterprise informatization, people are increasingly aware that traditional routers have become network bottlenecks; vswitches with layer-3 routing can work on the layer-3 protocol to replace or partially complete the functions of traditional routers, while having a speed of almost layer-2 switching, and the price is relatively low. Since there are many features and the price is low, it should be favored by enterprise users. How should we select switches?
　
How to select a vswitch:
　
(1) Selecting trusted technical indicators: Like any electronic product, when selecting a layer-3 switch, we should first analyze the performance indicators of various products. However, for example, switching capacity Gbps) and Board bandwidth Gbps), processing capability Mpps), throughput Mpps) and many other technical indicators, it is best to closely grasp the "throughput when full configuration", because other technical indicators users are not able to measure, all manufacturers have their own discretion. Only throughput is an indicator that users can directly measure and verify using testing instruments such as Smart Bits and IXIA.
　
(2) Select the correct product module: vswitches of different brands are completely different in technology, mainly divided into two categories: centralized and distributed. The traditional bus-type switching structure module is centralized, the modern Switching Matrix module is distributed. As the volume of audio, video, and data running on the enterprise intranet is growing, the requirements for switch processing capabilities are also increasing. In order to achieve high-speed and non-blocking switching under high port density conditions, it is wise to adopt a distributed layer-3 switch. In the Ethernet environment, the bus-type switch module can still avoid conflict tests, while the matrix mode avoids conflict during port switching.
　
(3) Pay attention to the latency and latency jitter indicators: the enterprise intranet is almost a high-speed LAN, which aims to transmit audio, video, and other large-capacity multimedia data, however, these large-capacity multimedia data packets do not require jitter in information transmission due to packet loss due to long latency. The latency of some traditional centralized switches is as high as 2 milliseconds, while that of some modern distributed switches is only about 10 microseconds, the difference between the two is hundreds of times. The delay is usually caused by blocking the design of the switching structure, excessive use of buffering, and so on. Therefore, attention to latency actually requires attention to the module structure of the product.
　
(4) stable performance: layer-3 switches are mostly used for backbone and aggregation layers and are placed at the network center gate. If the performance is unstable, Most hosts in the network system and even the entire network system are affected. Therefore, only layer-3 switches with stable performance guarantee the continuous, reliable, secure, and normal operation of the network system. Of course, stable performance seems abstract, and it seems that historical detection is required to be persuasive. In fact, equipment performance is actually achieved through a number of basic technical indicators and market reputation. Therefore, you can test throughput, latency, frame drop rate, back-to-back function, Address Table depth, line-End Blocking, many-to-one function, and other indicators as well as market application surveys. The back-to-back switching capability directly affects the overall packet forwarding and data stream processing capabilities, which is of great reference value for stable performance.
　
Secure and reliable: As the layer-3 switch of the core network equipment, it is naturally an important target of hacker attacks, which requires that we must include the layer-3 switch in the scope of network security protection. Of course, the "security and reliability" mentioned here should include the software and hardware of the layer-3 switch. Therefore, in terms of "security", a layer-3 Switch with excellent performance and no security vulnerability firewall is necessary. From the perspective of "reliability", it is a matter of concern that any product cannot guarantee that it will not fail, and whether the product can quickly switch to a good device in case of a fault.
　
In addition, the hardware should consider redundancy capabilities, such as power supply, management module, port and other important components, whether redundancy is supported, which is especially important for users with high security and reliability requirements such as telecom and finance. The other is the heat dissipation method, such as whether the fan is set properly and beautiful. The final consideration is what kind of security international or national standards are met for the product, such as electromagnetic radiation standards and various security standards. Another important aspect for broadband operators is certification. In the past, vswitches were used by enterprises and directly connected to the Internet without authentication. However, the broadband operator needs to confirm whether the user is recorded. When a user accesses the Internet, a window appears, and the user name and password can pass the authentication. Therefore, the layer-3 switch of the broadband operator should also support some special protocols such as 802.1x for authentication.
　
Complete functions: the product not only needs to meet existing needs, but also needs to meet the needs in the future, so as to provide users with a value-added space and ensure network expansion in the future. For example, when the number of employees increases, you can add modules to expand without removing the original equipment. There are also some functions, such as multicast, QoS, port trunk port trunking), 802.1d Spanning Tree, and whether RIP, OSPF, and other routing protocols are supported, it is very important for layer-3 switches. If not supported, it is difficult to meet user needs.