HA Router Policy Handoff Using Packet Header Actions
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Solution Overview
Problem
In software-defined wide area network (SDWAN) environments, redundant policy lookups are required when transferring packets between high availability (HA) standby and active routers, leading to inefficient use of computing resources and increased processing time due to multiple policy lookups.
Innovation Solution
Perform a policy lookup at a first router and include the policy action in the header of the data packet, allowing the second router to process the packet without performing a second lookup, thereby optimizing packet handling in HA clusters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If policy lookup is performed at both standby router and active router, then packet processing can be completed, but computing resources are wasted and processing time increases
Solution Approach 1:
The standby router performs the policy lookup action in advance before the packet arrives at the active router. The policy action is determined and prepared ahead of time, so when the packet is received at the active router, the policy action is already known and can be applied directly without performing another lookup.
Solution Approach 2:
The patent introduces an intermediary mechanism where the policy action is transmitted from the standby router to the active router through packet headers or control signals. This intermediary carrier allows the policy decision to be shared between routers, eliminating the need for redundant lookups at both routers.
2Reliability
If multiple policy lookups are performed in HA cluster, then correct NAT action can be determined, but computational costs increase
Solution Approach 1:
The policy lookup is performed preliminarily at the standby router before packet processing at the active router. This preliminary action determines the correct NAT action in advance, ensuring accuracy while avoiding redundant computational efforts at the active router.
Solution Approach 2:
The patent extracts the policy lookup operation from the active router's packet processing path and relocates it to the standby router. This extraction removes the redundant computational burden from the active router while maintaining the correctness of NAT action determination.
3Reliability
If redundant policy lookups are performed, then packet handling can be completed, but processing time increases
Solution Approach 1:
The policy lookup is performed as a preliminary action at the standby router before the packet reaches the active router. This timing optimization ensures that the policy action is ready in advance, eliminating time-consuming redundant lookups during packet processing at the active router.
Solution Approach 2:
The patent establishes continuous cooperation between standby and active routers where the standby router's policy determination is continuously valid and can be immediately applied at the active router. This continuity eliminates interruptions and redundant processing steps, streamlining the overall packet handling process.
Data Source
AI summary
In one aspect, a method includes receiving, at a first router, a data packet from a network device via a communication channel, executing, by the first router, a policy lookup for the data packet to determine a policy action for handling the data packet, including, by the first router, the policy action in a header of the data packet, and transmitting, by the first router, the data packet to a second router where the second router processes the data packet based on the policy action included in the header of the data packet.