VPN Route Distinguishers for Same-Destination Path Diversity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for providing path diversity in VPNs, such as the add-path method for MP-BGP, disrupt the routing infrastructure and are not scalable, especially in heterogeneous networks, and do not effectively address the need for load balancing across VPNs.
Innovation Solution
Utilizing multiple route distinguishers assigned to a single VRF to advertise prefixes with different service labels, allowing a Provider Edge device to load balance traffic across multiple customer edge devices within a VPN.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the add-path method is used to advertise multiple paths using extended NLRIs with path-id, then path diversity is improved, but the routing infrastructure is disrupted and scalability is reduced
Solution Approach 1:
The patent changes the parameter used for path identification from path-id (in add-path) to route distinguisher (RD). By assigning multiple RDs to a single VRF and using them to advertise prefixes, the system achieves path diversity without modifying the MP-BGP update message format or disrupting the routing infrastructure. This parameter substitution resolves the contradiction by maintaining compatibility while enabling multiple paths.
2Productivity
If multiple route distinguishers are assigned to a single VRF to advertise prefixes for multiple CE devices, then load balancing is improved, but the complexity of route management increases
Solution Approach 1:
The patent makes the route distinguisher serve multiple functions: it traditionally identifies a VRF, but now it also identifies multiple paths within a single VRF. This multi-functionality allows the same RD mechanism to provide both VRF identification and path differentiation, achieving load balancing without adding new management complexity.
Solution Approach 2:
The patent creates multiple copies of the same prefix advertisement, each with a different route distinguisher. These copied route advertisements enable the same prefix to be advertised multiple times with different next hops, facilitating load balancing while using existing BGP mechanisms without increasing management complexity.
3Adaptability or versatility
If the add-path method is implemented across all prefixes of a given SAFI, then path diversity is achieved, but additional scale stress is imposed on the routing information base
Solution Approach 1:
The patent applies path diversity selectively rather than universally. By using multiple route distinguishers only when needed for specific prefixes requiring multiple next hops, rather than applying add-path to all prefixes of a SAFI, the system achieves path diversity where necessary while minimizing the scale stress on the routing information base.
Data Source
AI summary
This disclosure describes techniques for using multiple route distinguishers assigned to a single VRF to provide same-destination path diversity in a VPN. In an example, a method includes storing, by a device, to a single virtual routing and forwarding instance (VRF) of one or more VRFs configured for a network device of a network, a plurality of routes for a common address prefix of a virtual private network (VPN); and sending, by the device to a network router, each of the plurality of routes for the common address prefix with a different, corresponding route distinguisher.