EVPN Route Reduction via Provider Edge Suppression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In Ethernet Virtual Private Networks (EVPN) with many provider edge (PE) nodes homed to the same subnet, redundant route advertising leads to a significant burden on software/control plane and hardware resources, particularly in BGP, RIB, FIB, and ECMP resources, due to unnecessary processing and storage of redundant subnet routes.
Innovation Solution
Implementing a method where a subset of PE nodes is elected to advertise subnet routes, reducing the number of redundant route advertisements by suppressing local path advertisements when remote paths are preferred, and installing only the top paths in the RIB and FIB resources, thereby optimizing resource consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If all PE nodes advertise the same subnet route in the network, then stretched subnet connectivity is maintained, but redundant route advertising and storage introduces significant burden on software/control plane and hardware resources
Solution Approach 1:
The patent extracts only the necessary route information from all PE nodes by suppressing redundant advertisements. Specifically, when a PE node receives route advertisements for a common subnet from multiple remote PE nodes, it suppresses sending its own local path advertisement if there are at least a predetermined number of remote paths preferred over the local path, thereby taking out only the essential routing information needed for connectivity.
Solution Approach 2:
The patent applies partial action by selecting only the top preferred paths rather than processing all possible routes. When determining which paths to advertise, the system considers only the top preferred paths based on route distinguishers and local route distinguishers, avoiding the excessive processing of all possible route combinations while maintaining sufficient connectivity.
2Loss of information
If PE nodes process and store all subnet routes in RIB and FIB resources, then complete routing information is available, but unnecessary processing and storage of information increases resource consumption
Solution Approach 1:
The patent extracts only the necessary route information from all PE nodes by suppressing redundant advertisements. Specifically, when a PE node receives route advertisements for a common subnet from multiple remote PE nodes, it suppresses sending its own local path advertisement if there are at least a predetermined number of remote paths preferred over the local path, thereby taking out only the essential routing information needed for connectivity.
Solution Approach 2:
The patent changes the parameter of route advertisement suppression based on path preference metrics. The system dynamically adjusts which routes are advertised by comparing route distinguishers and local route distinguishers to determine path preferences, thereby changing the set of active route advertisements to minimize resource consumption while maintaining routing completeness.
3Productivity
If all PE nodes advertise local paths for common subnets, then local routing is optimized, but redundant advertisements increase ECMP resource consumption
Solution Approach 1:
The patent extracts only the necessary route information from all PE nodes by suppressing redundant advertisements. Specifically, when a PE node receives route advertisements for a common subnet from multiple remote PE nodes, it suppresses sending its own local path advertisement if there are at least a predetermined number of remote paths preferred over the local path, thereby taking out only the essential routing information needed for connectivity.
Solution Approach 2:
The patent applies partial action by selecting only the top preferred paths rather than processing all possible routes. When determining which paths to advertise, the system considers only the top preferred paths based on route distinguishers and local route distinguishers, avoiding the excessive processing of all possible route combinations while maintaining sufficient connectivity.
Data Source
AI summary
A method is performed at a provider edge node configured to communicate with remote provider edge nodes over an Ethernet virtual private network. The method includes receiving, from the remote provider edge nodes, route advertisements for a common subnet hosted on the remote provider edge nodes. The route advertisements include distinct remote route distinguishers, a common IP prefix for the common subnet, and remote paths for the common subnet. The method further includes determining whether there are at least a predetermined number of the remote paths preferred over a local path for the common subnet hosted on the provider edge node based on the remote route distinguishers and a local route distinguisher for the local path. The method includes, when there are at least the predetermined number of the remote paths preferred over the local path, suppressing sending of a route advertisement for the local path for the common subnet.