Classification and summary of switch stack Technology

The switch stack technology is divided into many sub-categories, including star stack and Chrysanthemum chain stack. The application of the traditional switch stack technology is often limited by many geographical locations, it can be implemented only when it is placed in the same rack.

Stack technology is another type of technology that currently uses a large number of port extensions on Ethernet switches. It is a non-standard technology. Different vendors do not support hybrid stack. The stack mode is determined by each vendor and does not support the topology structure. Currently, there are two popular stacking modes: Chrysanthemum chain mode and star mode. The biggest advantage of stack technology is that it provides simplified local management and manages a group of switches as an object.

Chrysanthemum chain stack is a stack Technology Based on the cascade structure. It has no special requirements on the switch hardware. It supports port concatenation and software at a relatively high speed, finally, we can build a multi-switch cascade structure. Through the loop, we can achieve redundancy to a certain extent.

However, in terms of exchange efficiency, the same-level connection mode is at the same level. The Chrysanthemum chain stack usually uses one high-speed port and two high-speed ports. The structure of the two is shown in. In a high-speed port GE) mode, the uplink and downlink of the same port are respectively sent and received, forming a ring structure. data exchange between any two member switches takes one week, switch ports of all vswitches.

Low efficiency, especially when many layers are stacked, the stacked port will become a serious system bottleneck. Two high-speed ports are used to implement chrysanthemum chain stacking. Because more high-speed ports are occupied, you can choose to implement ring redundancy. Compared with the cascade mode, the chrysanthemum chain stack mode does not have topology management and generally cannot be distributed. It is applicable to single-node organizations that require high-density ports and can be used on the edge of the network.

Due to the need to eliminate the broadcast storm caused by the loop, the chrysanthemum chain structure is normally at any time, A route entry from a vswitch to a master vswitch can only use one high-speed port, that is, one high-speed port cannot share the uplink data pressure of the vswitch. All upstream switches must exchange data.

Chrysanthemum chain stack is a type of simplified stacking technology. It is mainly an extended port technology that provides centralized management, for the forwarding efficiency between multiple switches, the efficiency of the Single Port mode will be much lower than that of the cascade mode), the hardware must provide more high-speed ports, and the software must implement up link redundancy. Generally, the number of layers of chrysanthemum chain stacks should not exceed four layers. all Group members must be placed close enough to the same rack ).

The star stack technology is an advanced stack technology. For switches, an independent or integrated high-speed switching center stack center is required ), all stacked hosts are uplinked to a unified stack center through dedicated or general high-speed ports. The stack center is generally a dedicated ASIC-based hardware switching unit, based on its switching capacity, the bandwidth is generally between 10-32 GB, and its ASIC switching capacity limits the number of layers in the stack.

The star stack technology reduces the number of switches of all Stack Group members to a level of Matrix in the stack center. forwarding between any two end nodes only requires three exchanges, the forwarding efficiency is the same as the communication structure of edge nodes in the first-level connection mode. Therefore, compared with the chrysanthemum chain structure, it can significantly increase the data forwarding rate between stacked members, provides a unified management mode. A group of switches can appear as a single node in network management.

The star stack mode is applicable to a single-node LAN that requires high-efficiency and high-density ports. The star stack mode overcomes the high latency impact of multi-layer forwarding in the chrysanthemum chain stack mode, but needs to provide a high-bandwidth Matrix, the cost is high, and the Matrix interface is generally not universal. The stacked ports of both the stack center and the member switch cannot be used to connect to other network devices.

Using a highly reliable and high-performance Matrix chip is the key to star stack. Generally, the bandwidth of stacked cables is two-way between 2G and 2g), slightly higher than that of general GE. The higher part is usually used only for member management, so the effective data bandwidth is basically similar to GE. However, due to the dedicated bus technology, the cable length generally cannot exceed 2 m. Therefore, in star stack mode, all switches must be limited to one rack.

It can be seen that the traditional stack technology is a centralized management port expansion technology, which cannot provide topology management, has no international standards, and has poor compatibility. However, in a single-node LAN that requires a large number of ports, star stack provides excellent forwarding performance and convenient management features.

Level-based connections are the basis for building networks. They can use various topologies and redundancy technologies flexibly. When there are too many layers, they need to be carefully designed. For networks with few levels of connection, the connection mode can provide optimal performance. For example, in a network that needs to be expanded to double the port number.

The edge of a star stack needs to be exchanged three times, the cascade mode and the chrysanthemum chain stack need to be exchanged twice, and the star stack mode requires greater investment, the Chrysanthemum chain stack mode requires more high-speed ports, and the common level is the most economical and efficient way to build. In addition, you can also use existing exchange devices without repeated investment. However, these two devices need to be managed separately.

1. Correct Interpretation and test of vswitch Port
2. Summarize the market status of high-end Switches
3. Focuses on core layer switch faults
4. PythonAndroid
5. Let's talk about the stacking of Ethernet switches.