One-arm BFD Echo Packet Routing in VXLAN Multi-active Gateways
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Solution Overview
Problem
In a VXLAN multi-active gateway scenario, the existing one-arm BFD echo packet detection mechanism fails to accurately determine network device faults due to hash-based path selection, leading to incorrect fault detection and service disruptions.
Innovation Solution
The method involves using identification information, such as unique destination addresses, in one-arm BFD echo packets to ensure correct routing and reception of echo packets between gateway devices, thereby establishing effective BFD echo sessions and preventing incorrect fault detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If hash algorithm-based path selection is used to return one-arm BFD echo packets, then packet routing efficiency is improved, but BFD echo session establishment reliability deteriorates
Solution Approach 1:
The patent segments the BFD echo packet return process into two independent parts: (1) the data plane packet forwarding uses hash algorithm-based path selection for efficiency, while (2) the BFD control plane uses identification information (MD/YD) to ensure reliable echo session establishment. This segmentation allows each plane to optimize for its specific function without interference.
Solution Approach 2:
The patent introduces identification information (MD and YD fields) as an intermediary mechanism between the BFD echo packet and the gateway device. This intermediary ensures that even though packets are routed efficiently through hash-based path selection, the BFD echo session can still be reliably established by matching the identification information, thus resolving the contradiction between efficiency and reliability.
2Reliability
If multiple gateway devices share the same VTEP address in VXLAN multi-active gateway scenario, then gateway service availability is improved, but BFD echo packet detection accuracy deteriorates
Solution Approach 1:
The patent applies local quality by assigning unique identification information (MD and YD) to each gateway device's BFD echo sessions. This allows each gateway device to be uniquely identified in the BFD detection process, enabling accurate fault detection for each individual gateway while maintaining the multi-active gateway service availability provided by shared VTEP addresses.
Solution Approach 2:
The patent introduces asymmetry in the BFD echo packet structure by including gateway-specific identification information (MD and YD fields). This asymmetric feature allows the system to distinguish between multiple gateway devices with the same VTEP address, enabling precise fault detection for each gateway while preserving the high availability benefits of the multi-active gateway configuration.
Data Source
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AI summary
This application provides a packet processing method and a gateway device. The method includes: A first gateway device receives, by using a first link, a first one-arm BFD echo packet returned by a network device, where the first one-arm BFD echo packet includes identification information, and the identification information is used to uniquely identify a second gateway device. The first gateway device determines, based on the identification information, to forward the first one-arm BFD echo packet to the second gateway device. The first gateway device sends the first one-arm BFD echo packet to the second gateway device. The network device is multi-homed connected to the first gateway device and the second gateway device. The network device is connected to the first gateway device by using the first link, and the network device is connected to the second gateway device by using a second link. The first gateway device and the second gateway device form a multi-active gateway. According to the method provided in this application, efficiency of detecting, by using a one-arm BFD echo session, whether the network device is normal in a VXLAN multi-active gateway scenario is improved.