Label Forwarding Entry Generation for Segment Routing Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current route importing-based methods for cross-area communication in segment routing increase network device instability and storage pressure due to route flapping and the need to store routing information from other areas.
Innovation Solution
A label forwarding entry generation method where a first network device obtains a packet with a third network device's address and prefix segment identifier from a second network device within the same area, determining a routing entry and generating a label forwarding entry independently, thus avoiding route importing and reducing storage pressure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If route importing-based method is used for cross-area communication, then inter-area communication is implemented, but network device stability deteriorates due to route flapping impact
Solution Approach 1:
The patent divides the network into multiple independent areas (area 1, area 2, etc.) where each area maintains its own routing information independently. Area 1 network devices only store routing information for area 1 network devices, while area 2 network devices store routing information for area 2 network devices. This segmentation isolates route flapping impacts to individual areas, preventing propagation across the entire network and thereby improving network device stability.
Solution Approach 2:
The patent introduces area border devices (ABRs) as intermediaries that handle cross-area communication. ABRs import routes from other areas and perform route conversion, acting as a buffer between different areas. This intermediary mechanism allows inter-area communication while protecting internal area network devices from external route flapping impacts, thus improving stability.
2Adaptability or versatility
If route importing-based method is used for cross-area communication, then inter-area communication is implemented, but storage pressure increases due to routing information from other areas
Solution Approach 1:
The patent segments routing information storage by area, so that network devices in area 1 only store routing information for area 1 network devices, and network devices in area 2 only store routing information for area 2 network devices. This segmentation dramatically reduces the quantity of routing information each device must store while maintaining inter-area communication capability through area border devices that handle cross-area route imports.
3Reliability
If area-independent routing is implemented, then route flapping impact is isolated, but inter-area communication efficiency may be affected
Solution Approach 1:
The patent uses area border devices as intermediaries to maintain efficient cross-area communication. ABRs import routes from other areas and perform route conversion, enabling direct routing decisions at area border devices while isolating internal area devices from external route changes. This intermediary approach preserves communication efficiency by avoiding the need for internal area devices to process external routing information.
Data Source
AI summary
This application provides an example label forwarding entry generation method, applied to a first network device. The method includes obtaining a first packet sent by a second network device, where the first packet carries an address of a third network device and a prefix segment identifier of the third network device, the first network device and the second network device belong to a first area, and the third network device belongs to a second area. The method also includes determining a routing entry that matches the address of the third network device, where the routing entry includes an address of a next-hop network device of the first network device. The method further includes generating a label forwarding entry based on the prefix segment identifier and the address of the next-hop network device.