BGP Peer Route Refresh Control for VPN Route Limits
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Solution Overview
Problem
In VPN cross-domain networking scenarios, existing technologies fail to effectively limit the number of VPN routes in Option B and Option C modes, leading to resource occupation and interference with other VPN instances.
Innovation Solution
A routing control method using Border Gateway Protocol (BGP) Peers to manage VPN routes by setting and enforcing route limits through Route Refresh messages with Outband Router Filtering (ORF) entries, allowing real-time control and filtering based on Route Distinguishers (RDs) to prevent excessive VPN routes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If VPN route advertising is allowed without limitation in Option B and Option C modes, then VPN networking flexibility is improved, but resource occupation increases and interference with other VPN instances occurs
Solution Approach 1:
The patent applies preliminary action by configuring outbound route filters on ASBRs before VPN route advertising occurs. These filters are prepared in advance based on VRF routing table status, preventing excessive route accumulation before it happens. The system proactively sets up filtering rules that will automatically limit routes for specific VPN instances, ensuring resource protection before the problem manifests.
Solution Approach 2:
The patent implements feedback mechanisms where ASBRs monitor VRF routing table status and dynamically adjust route advertising behavior. When the number of routes in a VRF table approaches thresholds, the system provides feedback to limit further route addition. This closed-loop control prevents resource exhaustion while maintaining flexible VPN networking within safe boundaries.
2Quantity of substance
If VPN route limitation is implemented using VRF routing tables in Option A mode, then resource occupation is controlled, but the solution cannot be applied to Option B and Option C modes
Solution Approach 1:
The patent achieves universality by designing a route limitation mechanism that works across Option A, Option B, and Option C modes. Instead of mode-specific solutions, it implements a general framework using outbound route filters on ASBRs that can be configured regardless of the VPN cross-domain mode. This multi-functional approach allows the same mechanism to control route numbers in all three modes, enhancing adaptability while maintaining resource control.
Solution Approach 2:
The patent introduces outbound route filters as an intermediary layer between route reception and VRF routing tables. This mediator component sits at the ASBR level and intercepts VPN routes before they enter the VRF tables, providing a universal control point that works across different modes. The filter acts as a buffer that can be configured to limit routes for specific VPN instances, making the solution applicable to all modes while maintaining resource control.
3Loss of energy
If ASBRs continuously monitor and filter VPN routes to prevent excessive accumulation, then resource usage is optimized, but system complexity increases
Solution Approach 1:
The patent applies self-service by enabling ASBRs to autonomously monitor their own VRF routing table status and automatically adjust route advertising behavior. The ASBRs independently evaluate whether to accept or filter incoming VPN routes based on pre-configured thresholds and identifiers, without requiring external control plane intervention for each decision. This self-managing approach optimizes resource usage while avoiding the complexity of centralized monitoring systems.
Data Source
AI summary
The present disclosure relates to a routing control method, a system, and a BGP Peer. The method of the present disclosure can be executed by a first BGP Peer, including: receiving information of adding a new VPN route sent from a second BGP Peer, wherein the information of adding the new VPN route comprises: the new VPN route and an identifier of a first VPN instance; determining whether a number of VPN routes corresponding to the identifier of the first VPN instance reaches or exceeds a limit value after adding the new VPN route; and sending first instruction information to the second BGP Peer to instruct the second BGP Peer, in a case that the number of VPN routes corresponding to the identifier of the first VPN instance reaches or exceeds the limit value, wherein the first BGP Peer is an iBGP Peer inside a first AS.