Standby Network Controller Failover via VRRP
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current network systems experience prolonged network outages due to the requirement that both the access point and network controller must jointly determine the failure of the master network controller before transitioning to the standby controller, leading to delayed activation of tunnels and extended downtime for access points and client devices.
Innovation Solution
Implementing a method where the standby network controller initiates a failover request upon detecting the master controller's failure through Virtual Router Redundancy Protocol (VRRP) advertisements, allowing for immediate activation and minimizing downtime by not waiting for the access point's determination of the master controller's failure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the access point waits for joint determination of master controller failure before transitioning to standby controller, then network access reliability is improved, but network access downtime increases
Solution Approach 1:
The standby network controller pre-establishes tunnel connections to access points in advance, so that when failover is needed, the tunnels are already prepared and can be activated immediately. This preliminary preparation eliminates the time required for tunnel establishment during failover, resolving the contradiction between reliability and downtime.
Solution Approach 2:
The patent separates the failure detection function from the failover execution function. The standby controller independently detects master controller failure through VRRP advertisements and can initiate failover without waiting for access point confirmation. This segmentation allows the system to maintain reliability through proper failure detection while reducing downtime by enabling immediate failover execution.
2Measurement precision
If the standby controller waits for access point confirmation of master controller failure before initiating failover, then failover accuracy is improved, but failover speed decreases
Solution Approach 1:
The standby controller continuously monitors VRRP advertisements from the master controller and pre-prepares tunnel connections before failure occurs. When the master controller fails, the standby has already detected the failure through missing VRRP advertisements and has pre-established tunnels ready for immediate activation, achieving both accurate failure detection and rapid failover.
Solution Approach 2:
The patent uses VRRP advertisements as an intermediary mechanism for failure detection. The standby controller detects master controller failure through the absence of VRRP advertisements rather than waiting for access point confirmation. This intermediary approach provides reliable failure detection while enabling the standby controller to initiate failover independently and immediately.
3Measurement precision
If the system requires joint determination by access point and network controller for failover, then failover decision accuracy is improved, but system complexity increases
Solution Approach 1:
The standby network controller performs self-service by independently detecting master controller failure through VRRP advertisements and autonomously initiating failover without requiring access point confirmation. This self-service approach maintains accurate failover decisions through reliable VRRP-based detection while simplifying the system by eliminating the need for complex coordination and confirmation protocols between access points and controllers.
Data Source
AI summary
A system is described that includes a first network controller and a second network controller. The first controller operates as a master controller and the second controller operates as a standby controller for a set of access points. Using a set of VRRP advertisements between the first and second controllers, the second controller may (1) determine that the first controller has failed independent of any determination by the access points and (2) send a failover request to the access points. The failover request may cause the access points to use previously established tunnels between the second controller and each of the access points. By transmitting a failover request message from the second controller to the access points upon the detection by the second controller that the first controller has failed and independent of any determination by the access points, the system reduces network access downtime for the access points.