CLACP Protocol for ASA Cluster Link Aggregation

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Solution Overview

Problem

Current link aggregation protocols, such as LACP, are limited in supporting multipoint aggregations and fail to provide effective link aggregation control in cluster environments, leading to traffic 'black holes' and inefficiencies during port or link failures in ASA clusters.

Innovation Solution

The implementation of a Cluster Link Aggregation Control Protocol (CLACP) that aggregates links among multiple ASAs, providing a distributed protocol for dynamic link aggregation, auto-configuration, and load-balancing, while maintaining compatibility with standard LACP devices, to prevent traffic black holes and ensure high availability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If standard LACP is used for link aggregation, then compatibility with existing devices is maintained, but multipoint aggregations in cluster environments are not supported leading to traffic black holes

Engineering Contradiction:
Improvemultipoint aggregation supportVSAvoidtraffic black hole prevention
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The protocol is segmented into two distinct parts: standard LACP for basic link aggregation compatibility, and CLACP extensions specifically for multipoint cluster environments. This segmentation allows each protocol to optimize for its specific use case without compromising the other.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

CLACP acts as an intermediary layer that sits on top of standard LACP, adding cluster-specific functionality while maintaining compatibility with existing LACP implementations. The intermediary protocol translates cluster requirements into LACP-compatible operations.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If manual link aggregation configuration is used, then control over port distribution is achieved, but complexity increases and automatic adaptation to failures is lost

Engineering Contradiction:
Improveautomatic failure adaptationVSAvoidaggregation control mechanism
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The CLACP implementation enables the network system to automatically detect link failures, recalculate optimal port distributions, and reconfigure aggregations without manual intervention. The system serves itself by monitoring its own state and making necessary adjustments.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The protocol incorporates continuous feedback mechanisms where cluster members exchange status information about link states and port configurations. This feedback loop enables automatic detection of failures and triggers appropriate reconfiguration actions to maintain optimal performance.

Inventive Principle:
Principle #23Feedback

3Productivity

If link aggregation is implemented without cluster-specific control, then setup is simpler, but load-balancing efficiency decreases during port or link failures

Engineering Contradiction:
Improveload-balancing efficiencyVSAvoidcluster coordination protocol
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The CLACP implementation makes the link aggregation configuration dynamic rather than static. Port assignments and aggregation memberships are continuously adjusted based on real-time cluster conditions, enabling optimal load balancing even during failures.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The protocol dynamically changes key parameters such as port priorities, aggregation weights, and member selections based on cluster state. These parameter changes enable the system to adapt load-balancing behavior to current conditions while maintaining efficient traffic distribution.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2875614B1System and method for cluster link aggregation control in a network environment
Publication Date: 2018.10.17 CISCO TECHNOLOGY INC
  • EP2875614B1 patent drawingFigure 1~2
  • EP2875614B1 patent drawingFigure 3~4
  • EP2875614B1 patent drawingFigure 5~6

AI summary

A method is provided in one example and includes receiving a request message from a first network element using an out-of-band control link. The request message includes a request to bundle a first port associated with the first network element into a channel group associated with a cluster. The cluster includes a plurality of clustered network elements. The method further includes determining a status of the first port with respect to the channel group, and sending a reply message to the first network element using the out-of-band control link. The reply message indicates the determined status of the first port of the first network element.