AS Path Verification for Inter-Domain Traffic Redirection
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Solution Overview
Problem
Inter-domain traffic redirection in BGP is often transparent, leading to issues such as traffic black holes and loops due to unknown AS paths, which are not detected by routing protocols.
Innovation Solution
A method and apparatus for verifying the validity of inter-domain redirection paths by checking the AS sequence against a verification strategy, ensuring the path is valid before forwarding traffic.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If inter-domain traffic redirection is configured on ASBR, then traffic can be forwarded according to customized rules, but the AS path becomes unknown and causes traffic black holes or loops
Solution Approach 1:
The patent applies preliminary action by performing path validity verification before traffic forwarding. The ASBR verifies the AS path obtained through redirection using a verification strategy that checks whether the AS sequence meets preset requirements (e.g., AS path length, specific AS presence). This pre-verification ensures path validity before traffic is redirected, preventing black holes and loops while maintaining customized forwarding control.
2Adaptability or versatility
If redirection operation is performed to obtain customized AS path, then traffic forwarding flexibility is improved, but path validity cannot be ensured
Solution Approach 1:
The patent implements feedback by using the verification strategy to check the AS path obtained through redirection. The verification process provides feedback on whether the customized AS path is valid by checking if it meets preset requirements. If the path fails verification, the redirection is not applied, thus maintaining reliability while allowing flexibility for valid customized paths.
3Device complexity
If routing protocol transparency is maintained for redirection, then protocol simplicity is preserved, but traffic loops and black holes occur due to unknown AS path
Solution Approach 1:
The patent introduces an intermediary verification mechanism between the redirection configuration and traffic forwarding. The verification strategy acts as an intermediary that checks the AS path validity without requiring changes to the BGP routing protocol itself. This maintains protocol simplicity while ensuring traffic transport reliability through the intermediate verification step.
Data Source
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Figure 1b
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AI summary
This application discloses a path validity verification method, a redirection path obtaining method, and an apparatus. A first network device obtains a first AS path obtained through inter-domain traffic redirection, and verifies validity of the first AS path according to a verification strategy, to obtain a verification result. The verification strategy is used to verify validity of an AS sequence included in the first AS path. To be specific, for an AS path obtained through inter-domain traffic redirection, the first network device may verify validity of an AS sequence included in the AS path, to ensure that the AS path obtained through redirection is a valid path, and ensure normal transport of inter-domain traffic.