Everything You Should Know About Switch Stacking

As important technical means to achieve redundant terminal access and redundant link backup, stacking and M-LAG can significantly improve the reliability and scalability of data center networks. However, although they have many similarities, they have their own advantages and disadvantages and applicable scenarios in actual applications. This article will explore the basic principles, technical characteristics, advantages and disadvantages of stacking in depth, and through a detailed comparison of stacking technology and MLAG, help you make the best choice in a specific network environment.

Switch Stacking Basics

Stacking technology refers to combining multiple stacking-supported devices together to make them logically a whole device. Users can manage and use these devices as a single device. In this way, the number of ports and switching capacity can be expanded by adding devices, and the reliability of the device can be enhanced by mutual backup between multiple devices.

Switch stacking is a network configuration method that connects multiple physical switches together to form a logical switch. In this way, administrators can configure and manage all switches in the stack through a single interface. Usually, stacking connections are implemented through dedicated stacking ports or high-speed Ethernet links.

How Does Stacking Work?

The stacking system connects multiple physical switches together through dedicated stacking links to form a logical switch. There is usually a master switch (Master) and multiple backup switches (Backup) in the stacking system. The master switch is responsible for managing the entire stacking system, including functions such as configuration synchronization, fault detection and recovery.

Master-backup Switching

In a stacking system, if the master switch fails, the backup switch will immediately take over its management function to ensure the normal operation of the network. This design improves the redundancy and reliability of the system.

Data Forwarding

Data forwarding in the stacking system is completed by all member switches. Data packets can enter the stacking system through any switch and reach the destination through the optimal path. This design optimizes network traffic and reduces latency.

Configuration Synchronization

All switches in the stacking system share the same configuration file. After the administrator makes configuration changes on the master switch, these changes are automatically synchronized to all member switches, simplifying management operations.

Why Do We Need Stacking Technology?

Traditional campus networks usually use devices and link redundancy to ensure high reliability. However, there are some problems with this approach:

Low link utilization: Using redundant links can improve availability, but it usually leads to low link utilization. This is because under normal circumstances, only a portion of the redundant links are activated, while the other links are idle and not fully utilized.

High network maintenance costs: Managing multiple independent switches requires a lot of time and effort. Each switch needs to be configured and maintained separately, which increases the complexity and cost of network management.

To solve these problems, switch stacking technology was introduced.

Advantages & Disadvantages of Switch Stacking

Why should you consider using switch stacking technology? Here are some of the key benefits of switch stacking:

• Enhanced performance: Switch stacking can significantly improve network performance by combining the processing power of multiple switches into a single logical device. This means higher bandwidth, lower latency, and faster data transfer speeds to help support large-scale network traffic.

• Improved availability: Because switch stacking treats multiple switches as a single device, if a switch fails, traffic can automatically switch to other switches without manual intervention. This improves network availability and redundancy.

• Simplified management: Managing multiple independent switches can be complex. Switch stacking simplifies the management process, and administrators only need to manage one logical device instead of multiple independent devices. This reduces management costs and management complexity.

• Flexible expansion: As the organization's network needs continue to grow, more switches can be easily added to the stack to support new users and applications. This flexibility is not available in traditional network architectures.

Similarly, stacking technology also has certain disadvantages. The following are some disadvantages of switch stacking:

• Limited scalability: The number of stacks is usually capped, and different vendors have different stacking limits, which may not meet large-scale expansion requirements.

• Single point of failure: Although stacking improves system reliability, a failure in the stack master switch (Master) may cause performance degradation or management interruption of the entire stack system.

• Performance bottleneck: The bandwidth of the stack link may become a bottleneck, especially in a high-traffic environment, which may affect the performance of the entire stack system.

Switch Stacking vs. MLAG

Multi-chassis link aggregation group (MLAG) is a multi-device link aggregation technology designed to make two switches act as one switch. By bundling ports from different MLAG peer switches together to form a single logical link, MLAG provides increased link bandwidth and additional redundancy.

Switch stacking and multi-chassis link aggregation (MLAG) are two different network methods used to achieve high availability, redundancy, and increased bandwidth. Here is a comparison between the two:

FS Enterprise Switches With Stacking Support

FS S5860 Series Campus Switches

FS provides S5860 series campus switch models that support stacking technology. These models usually have stacking modules or stacking ports, and multiple switches can be connected together through stacking cables to achieve stacking.

Product Summary Table

Final Words

Switch stacking is an effective network configuration method that can simplify network management and improve network reliability and scalability. However, implementing switch stacking requires consideration of some possible issues, such as configuration errors and performance bottlenecks. With proper configuration and optimization, switch stacking can be a powerful tool in a network environment.