Stacking

What Is Stacking?

Stacking technology involves interlinking several stackable switches using stack cables, thereby creating a single, cohesive logical switch dedicated to routing data. As a prevalent form of horizontal virtualization, stacking enhances system dependability, augments port availability, boosts overall bandwidth, and streamlines network configuration.

Why Do We Need Stacking?

Traditional campus networks commonly rely on device and link redundancy to ensure robust reliability. However, this approach often leads to issues such as underutilized links and increased network maintenance expenses. To address these challenges, the adoption of stacking technology has become prevalent in modern network setups. By virtualizing multiple switches into a single entity, stacking simplifies network deployment and reduces maintenance costs significantly. The utilization of stacking technology offers various benefits:

• Enhancing reliability: Stacked switch members operate in redundancy mode, as depicted in the diagram. For instance, if SwitchA encounters a failure, SwitchB seamlessly takes over its functions to ensure uninterrupted service. Furthermore, inter-device link aggregation enables link redundancy between stack members.

• Increasing port availability: In scenarios where the original switch's port density does not meet user access demands, additional switches can be incorporated into the stack to augment the number of available ports.

• Boosting bandwidth capacity: When higher uplink bandwidth is necessary, incorporating new switches into the stack and aggregating the member switches' physical links can significantly enhance the uplink bandwidth capacity.

• Streamlining network configuration: Stacking multiple switches to create a unified logical switch streamlines networking operations, eliminating the need for loop prevention protocols like MSTP. Additionally, employing inter-device link aggregation ensures rapid convergence and bolsters reliability.

• Enabling long-distance stacking: By establishing a stack connecting access switches across multiple floors within a building, a cohesive network structure resembling a single switch can be achieved. This configuration enhances network robustness by providing multiple links to the core network for each building.

How to Configure a Stack?

Before diving into the setup process of a stack, it's essential to understand the fundamental concepts associated with stacking.

Primary, Backup, and Auxiliary Switches

When switches are integrated into a stack, they become member switches. These member switches can take on different roles within the stack:

Primary Switch

The primary switch is responsible for overseeing the entire stack. Each stack has only one primary switch.

Backup Switch

The backup switch acts as a contingency for the primary switch. A stack contains only one backup switch. In the event of the primary switch failing, the backup switch assumes control of all services and functions as the primary switch.

Auxiliary Switch

Auxiliary switches are tasked with forwarding services within the stack. A stack can have multiple auxiliary switches. A higher number of auxiliary switches within a stack results in improved forwarding performance.

With the exception of the primary and backup switches, all other member switches are considered auxiliary switches. If the backup switch malfunctions, an auxiliary switch steps in to fulfill the role of the backup switch.

Stack Member Identifier

A unique stack member identifier is assigned to each member within a stack for identification and management purposes.

Stack Priority

The stack priority dictates the role that a member will play during role elections within the stack. A higher priority value increases the likelihood of a member being elected as the primary switch.

Stacking on FS Devices

FS enterprise switches and data center switches support stacking, and stacking can only be achieved between switches of the same model or the same series of the same brand. Learn more about switch stacking here: Switch Stacking Explained: Basis, Configuration & FAQs.