Virtual Link Trunking Port State Configuration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing link technologies face difficulties in determining new links and blocking loops quickly, leading to periods where traffic cannot be forwarded over the network, which slows network performance, especially when traffic destined for a remote server enters a non-working link.
Innovation Solution
A method and system for virtual link trunking (VLT) that calculates a forwarding table index for active and inactive switch peers, retrieves pre-determined port blocking and unblocking actions from memory, and configures I/O ports based on changes to determine which VLT ports to block or unblock, thereby optimizing network traffic routing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If redundant links are provided to improve network reliability, then network reliability is improved, but network loops are created which require STP to manage
Solution Approach 1:
The patent segments the network into distinct active and inactive link states through VLT port configuration. By dividing the redundant link into functional states (active for data traffic, inactive for backup), the system maintains reliability while simplifying loop management through clear state separation rather than complex STP protocols.
Solution Approach 2:
The patent applies preliminary action by pre-configuring VLT port states and forwarding tables before failures occur. The system proactively establishes which ports should be active or inactive based on predetermined topology information, eliminating the need for reactive STP protocols to manage loops after they form.
2Object-generated harmful factors
If STP is used to remove network loops, then network loops are prevented, but links become underutilized as they remain inactive until primary link fails
Solution Approach 1:
The patent introduces dynamics by allowing links to transition between active and inactive states based on real-time failure detection rather than static STP blocking. The VLT system dynamically switches ports between states, enabling links to remain inactive during normal operation (avoiding loops) while being quickly activated when needed (maintaining utilization).
Solution Approach 2:
The patent implements feedback mechanisms where the system continuously monitors link status and automatically adjusts port states based on detected failures. This feedback loop replaces STP's static blocking with dynamic state changes, allowing links to be inactive during normal operation but quickly become active when failures occur, thus preventing loops while maintaining readiness.
3Productivity
If link aggregation is used to increase capacity, then data throughput is increased, but determining new links and blocking links to prevent loops takes excessive time
Solution Approach 1:
The patent applies preliminary action by pre-calculating and storing forwarding tables that map destination IP addresses to active VLT ports before failures occur. When a failure happens, the system simply looks up the destination in the pre-computed table rather than determining routing paths in real-time, dramatically reducing convergence time while maintaining aggregated throughput capability.
Solution Approach 2:
The patent uses copying by creating replicated forwarding tables at each switch peer that contain predetermined routing information. Instead of each switch independently calculating routing paths during failures, they all reference pre-computed copies of the forwarding table, enabling rapid response without time-consuming real-time calculations.
4Loss of time
If VLT ports are configured to failover quickly, then convergence time is reduced, but determining which ports to block requires complex calculations
Solution Approach 1:
The patent segments the complex port blocking determination into simpler components by using predefined forwarding table entries. Each entry in the forwarding table corresponds to a specific failure scenario and pre-determines which ports should be blocked, transforming a complex real-time calculation problem into simple table lookup operations.
Solution Approach 2:
The patent applies copying by replicating forwarding tables at each switch that contain pre-computed port blocking actions for various failure scenarios. Instead of each switch performing complex calculations to determine blocking actions, they simply retrieve pre-computed copies from their local tables, reducing both complexity and time requirements.
Data Source
AI summary
A method, an information handling system (IHS), and a virtual link trunking (VLT) system for determining VLT ports to block and unblock in an IHS. The method includes calculating a forwarding table index for a local switch of currently active and inactive switch peers for a VLT port. A pre-determined forwarding table is retrieved from a memory containing a plurality of port blocking and unblocking actions for the switch peers. Current port blocking and unblocking actions are identified in the pre-determined forwarding table corresponding to the forwarding table index. Changes are determined between the previous port blocking and unblocking actions and the current port blocking and unblocking actions. The input/output (I/O) ports are configured for the local switch based on the determined changes in the port blocking and unblocking actions.