MC-LAG Device Virtualization for STP Loop Prevention
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Solution Overview
Problem
Multichassis Link Aggregation Group (MC-LAG) technology faces issues with system stability due to inconsistencies in Spanning Tree Protocol (STP) calculations across devices, leading to potential loop risks and failures in link aggregation functions.
Innovation Solution
A device virtualization method that synchronizes bridge and port IDs between local and peer devices in an MC-LAG, using extended protocol messages based on STP to determine roles and states of ports, ensuring consistent calculations and avoiding loop risks by treating two devices as a single logical unit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If distributed STP calculation is performed independently on each device, then each device can autonomously determine port roles and states, but calculation results may block links or member ports in MC-LAG, causing MC-LAG function failure and poor system stability
Solution Approach 1:
The patent merges the STP calculation functions of multiple MC-LAG devices into a unified virtual device. The virtual device has a single bridge ID formed by combining device IDs of member devices, and performs centralized STP calculation rather than independent distributed calculations. This ensures consistent port role determination across all MC-LAG member devices and prevents link blocking that would occur with independent calculations.
Solution Approach 2:
The patent introduces a virtual device as an intermediary between physical MC-LAG devices and the STP protocol. The virtual device acts as a mediator that receives STP BPDUs, performs centralized calculation, and distributes consistent port role assignments to all member devices. This intermediary layer resolves the contradiction by enabling autonomous determination while ensuring consistency across the MC-LAG group.
2Reliability
If multiple devices are virtualized into one logical device by MC-LAG, then link aggregation reliability is enhanced, but distributed STP calculations create inconsistencies that block links and cause function failures
Solution Approach 1:
The patent combines the bridge IDs of multiple MC-LAG devices to form a single virtual bridge ID. This merging ensures that all devices participate in a unified STP calculation, maintaining calculation consistency information across the virtualized device group while preserving the link aggregation reliability benefits of MC-LAG.
3Adaptability or versatility
If independent STP calculations are performed on each device, then device autonomy is maintained, but loop avoidance effectiveness is reduced due to inconsistent calculation results
Solution Approach 1:
The patent merges STP calculation functions into a centralized virtual device while maintaining the autonomy of individual devices through automated virtual device management. The virtual device performs unified calculation that ensures loop avoidance effectiveness, while member devices automatically apply the calculated port roles without manual intervention, thus preserving operational autonomy.
Solution Approach 2:
The patent implements feedback mechanisms where the virtual device receives STP BPDUs from the network, performs centralized calculation, and distributes consistent port role assignments back to member devices. This feedback loop ensures that loop avoidance decisions are based on comprehensive network information while maintaining device autonomy through automated execution of calculated roles.
Data Source
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AI summary
The present application provides a device virtualization method, an apparatus, a system, a device, and a storage medium. The device virtualization method comprises: determining virtual information of a virtual device according to device information of a local device and device information of a peer device of a multichassis link aggregation group, wherein the local device and the peer device are multiple first devices of the multichassis link aggregation group, the device information comprises a network bridge identifier and a port identifier, and the virtual information comprises a virtual network bridge identifier and a target port identifier; exchanging an extension protocol packet with the peer device, wherein the extension protocol packet is generated on the basis of a spanning tree protocol packet received by the local device; and determining a role and a state of a port of the local device according to the virtual information and the extension protocol packet of the peer device in combination with a protocol packet received by the local device.