Gigabit L3 switches will be the core of the LAN in the future

Many may not have a special understanding of GE L3 switches. Here we will mainly introduce the future development direction of GE L3 switches. Now, the Internet industry is no stranger to the term "Gigabit Layer 3 Switch". In the construction of medium and large scale networks, mainstream network models with gigabit Layer 3 switch as the core are numerous. As a matter of fact, the emergence of GE L3 switches to the popularization and application of today is just a few years ago. The rapid development of computer network acceleration is amazing.

Layer 1 and Layer 2

Looking back at the early stages of the network, when applying LAN technology to networking, it was mainly limited to host connection, file sharing, and print sharing. Multiple users can share 10 Mb/s bandwidth to meet the requirements. As the network scale expands, the network system is no longer competent, because the earliest network interconnection device in the LAN is a hub, which is a layer of equipment. The collision detection and error re-transmission process of user data based on CSMA/CD physical protocol greatly reduces the transmission efficiency. At that time, a two-layer device bridge was used to reduce the network segment and the collision domain, thus optimizing the LAN performance. However, it is a device that is transparent to the upper layer (Layer 3 or above) protocol and cannot effectively prevent broadcast storms. Therefore, a router is required. Vrouters play a key role in subnet interconnection, security control, and broadcast storm restrictions. However, complicated algorithms and low data throughput make vrouters a network bottleneck. Aware of the above problems, the industry has improved the bridge, made a LAN switch, and used it to replace the hub to improve network performance.

A lan switch is a layer-2 network device that constantly collects and creates its own MAC address table during operations and regularly refreshes the table. It enables dedicated bandwidth between network sites, eliminates unnecessary Collision Detection and error re-transmission, and improves transmission efficiency. In addition, user information is transmitted point-to-point, and other nodes are invisible. However, layer-2 switching also exposes its weakness: it cannot effectively solve problems such as broadcast storms, inter-network interconnection, and security control. Therefore, the VLAN Virtual LAN technology on the switch is generated.

1-gigabit L3 switch and VLAN

The emergence of the "Gigabit L3 switch" concept is closely related to VLAN. In fact, a virtual network is a logical subnet. To avoid a broadcast storm caused by broadcasting on a large vswitch, You can further divide it into multiple virtual networks. In a virtual network, information sent by a workstation can only be sent to other sites with the same virtual network number. Other Virtual Network members cannot receive the information or broadcast frames.

As the network becomes more complex and the performance requirements become higher and higher, network administrators are required to successfully deploy VLANs to make the network more flexible and easy to manage. In the past, network administrators spent 3/4 of their time maintaining the network infrastructure, ensuring the optimization of communication traffic, and handling mobile and change work. Generally, when a user moves to another physical location in the network, the network needs to be reconfigured, and even the user's workstation needs to perform a lot of management work. To address this problem, VLAN deployment reduces the resources required for managing network movement and changes, thus saving a lot of valuable resources for users. VLAN technology can also provide users with value in the following key areas:

More cost-effective broadcast control than vrouters, effectively inhibiting broadcast storms, supporting multimedia applications and efficient multicast control, and improving the effective utilization of network bandwidth. To improve network security, various explicit or implicit VLAN division methods provide policy-based security access mechanisms, automated network supervision and management, and more effective network monitoring, reduces routing requirements. Based on ASIC Technology, this greatly improves the data packet forwarding capability of devices.

Vro challenges

How do VLANs communicate? The simple answer is "via routing ". Therefore, this technology also raises some new problems: communication between virtual networks is not allowed, which also includes IP Address Resolution (ARP) packets. To communicate, you need to use vrouters to bridge these virtual networks. This is the problem of virtual networks: vswitches are fast but cannot solve the broadcast storm problem. Using Virtual Network Technology in vswitches can solve the broadcast storm problem, however, you must place a vro to connect virtual networks. In this network system integration mode, routers are the core.

In the past, the network was generally allocated according to the "80/20" rule, that is, only 20% of the traffic was communicated with other parts of the central server or enterprise network through the backbone router, 80% of network traffic is still concentrated in subnets of different departments. Today, this proportion has been increased to 50% "evenly divided into autumn") or even 80% to 20/80,), because today's network is experiencing the collective influence of many applications. Network applications have surpassed components and e-mails, and the new applications have quickly and profoundly impacted the network. For example, anyone can access the set Web page through any browser, data Warehouses that support commercial functions such as sales, services, and finance.

This change has a direct impact on traditional routers. Because traditional routers focus more on multiple media types and transmission speeds, data buffering and conversion capabilities are more important than line rate throughput and low latency. The high cost and low performance of a router make it a bottleneck of the network. However, due to the need for interconnection between networks, it is indispensable and at the core of the network. Although high-speed routers have also been developed, they are only used for the backbone of the Internet because of their high cost.

What is a gigabit L3 switch?

In this case, a layer-3 switching technology is proposed. GE L3 switches are the key to adopting Intranet applications. They combine the advantages of L2 switches and L3 routers in an organic and intelligent manner into a flexible solution to provide line rate performance at all levels. This integrated structure also introduces policy management attributes, which not only associate Layer 2 with Layer 3, but also provides traffic prioritization, secure access mechanisms, and a variety of other flexible functions. A Gigabit L3 switch consists of three layers: LAN interface layer, L2 switching matrix layer, and L3 Switching Matrix routing control,