Redundant Switch System for Seamless Network Failover

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

In high-density computing or networking environments, if a single top-of-rack switch fails, devices connected to it become isolated from other devices due to the lack of redundant connections, leading to communication disruptions and potential packet loss or duplication during failover processes.

Innovation Solution

Implementing a redundant switch system with multiple switches, where one is active and others are in standby mode, allowing seamless failover by reconfiguring the upstream network to direct packets to the standby switch, minimizing packet loss and duplication, and ensuring consistent network information sharing among switches.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single top-of-rack switch is used to connect devices, then device connectivity is simplified, but network reliability deteriorates when the switch fails

Engineering Contradiction:

Improvenetwork configurationVSAvoidnetwork connectivity

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The network switch is segmented into multiple independent sub-network elements (first sub-network element and second sub-network element), each capable of independently forwarding packets. This segmentation allows the system to maintain connectivity through multiple paths, resolving the contradiction by improving reliability while keeping the overall architecture manageable through clear division of functions.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Multiple sub-network elements are merged into a single logical network element that presents a unified interface to connected devices. The standby sub-network element mirrors the active element's state and takes over seamlessly upon failure, combining redundancy with simplicity to maintain both high reliability and low configuration complexity.

Inventive Principle:

Principle #5Merging (Combining)

2Reliability

If redundant switches are implemented for failover, then network reliability is improved, but packet loss and duplication increase during failover

Engineering Contradiction:

Improvenetwork connectivityVSAvoidpacket loss

Core Design Contradiction:

ReliabilityVSLoss of information

Solution Approach 1:

The standby sub-network element performs preliminary actions by continuously mirroring the MAC address table and forwarding state of the active element before failover occurs. This pre-synchronization ensures that when failover happens, the standby element can immediately take over without causing packet loss or duplication, as it already has the necessary forwarding information ready.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The standby sub-network element creates an exact copy of the active element's forwarding state, including MAC address bindings and packet buffering state. This copying mechanism ensures seamless transition during failover, preventing packet loss by having the standby element resume forwarding from the exact point where the active element left off.

Inventive Principle:

Principle #26Copying

3Reliability

If redundant switches are implemented for failover, then network reliability is improved, but system complexity increases

Engineering Contradiction:

Improvenetwork connectivityVSAvoidswitch architecture

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

Both sub-network elements are designed with universal functionality, capable of operating as either active or standby elements. Each element has identical hardware and software capabilities, allowing either one to assume the active role. This multi-functionality reduces overall system complexity by eliminating the need for asymmetric designs and simplifying management procedures.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The redundant switch system implements self-service through automatic failover detection and execution. The sub-network elements continuously monitor each other's health and automatically perform state transitions without external intervention. This self-service mechanism reduces operational complexity by eliminating manual configuration changes during failover events.

Inventive Principle:

Principle #25Self-service

4Ease of operation

If seamless failover is achieved, then network transparency is maintained, but processing overhead increases

Engineering Contradiction:

Improvenetwork transparencyVSAvoidprocessing overhead

Core Design Contradiction:

Ease of operationVSUse of energy by moving object

Solution Approach 1:

The standby sub-network element performs partial synchronization by mirroring only the essential forwarding state (MAC address table and active packet buffer) rather than complete system state. This selective copying achieves seamless failover for packet forwarding while reducing processing overhead by excluding non-essential data from the mirroring process.

Inventive Principle:

Principle #16Partial or excessive action

Data Source

PatentUS11558240B2Network element with dual independent sub network elements with seamless failover

Publication Date: 2023.01.17 ARISTA NETWORKS INC

AI summary

A system that provides communication services may include two switches for redundancy. The switches may indicate that they are independent devices to upstream devices and indicate that they are the same device to a predetermined device set. If one of the switches enters an undesired state, then the switch in a standby state may modify the upstream devices to preferentially forward packets directed toward the predetermined device set to the standby switch rather than an active switch, and after transitioning the active switch to the standby state, transition the standby switch to the active state.