EVPN E-Tree IMET Routing for Leaf–Root BUM Isolation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing network devices struggle to efficiently handle Ethernet Virtual Private Network (EVPN) E-tree services, particularly in managing broadcast, unknown unicast, and multicast traffic (BUM) forwarding, leading to inefficient traffic isolation between root and leaf sites.
Innovation Solution
Implementing EVPN type-3 Inclusive Multicast Ethernet Tag (IMET) routes with an E-tree extended community that includes a leaf-indication flag to facilitate ingress filtering, allowing network devices to maintain floodlists for appropriate traffic forwarding and isolation between leaf and root sites.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If traditional EVPN routing is used without ingress filtering, then traffic forwarding is simpler, but overlay network traffic increases and traffic isolation between leaf and root sites is inefficient
Solution Approach 1:
The patent applies preliminary action by pre-establishing ingress filtering rules at the network edge devices before BUM traffic enters the overlay network. The controller configures floodlists and ingress filtering parameters in advance, enabling edge devices to filter and forward traffic efficiently without requiring complex real-time processing in the core network, thus reducing overall overlay traffic while maintaining manageable device complexity
Solution Approach 2:
The controller acts as an intermediary that manages the complexity of ingress filtering centrally. It distributes floodlist information and filtering rules to edge devices, allowing the complex traffic management logic to be handled by the controller rather than individual network devices. This reduces the burden on individual devices while achieving efficient traffic isolation and reduced overlay traffic
2Reliability
If floodlists are maintained at all network devices, then traffic isolation between leaf and root sites improves, but device complexity and memory requirements increase
Solution Approach 1:
The patent applies local quality by implementing ingress filtering and floodlist maintenance only at the edge devices that connect to the overlay network, rather than at all network devices. This localized approach ensures reliable traffic isolation at the critical boundary points while avoiding the need for complex floodlist management in core network devices, thus maintaining traffic isolation reliability without universally increasing device complexity
Solution Approach 2:
The controller serves as an intermediary that centralizes the management of floodlist information. It collects, processes, and distributes floodlist data to the appropriate edge devices, eliminating the need for each device to independently maintain complete floodlists. This approach ensures reliable traffic isolation through centralized coordination while reducing the complexity and memory requirements at individual device levels
3Reliability
If BUM traffic is forwarded without ingress filtering, then device operation is simpler, but traffic isolation between leaf sites and root sites is compromised
Solution Approach 1:
The patent applies preliminary action by pre-configuring ingress filtering rules and floodlists at edge devices before BUM traffic forwarding occurs. The controller establishes these filtering mechanisms in advance, allowing edge devices to automatically apply the correct filtering logic without requiring complex real-time decisions during traffic forwarding. This ensures reliable traffic isolation while keeping the actual forwarding operation simple and automated
Solution Approach 2:
Edge devices are empowered to perform ingress filtering and BUM traffic forwarding autonomously based on pre-configured rules from the controller. Each edge device independently applies the flooding logic and filtering criteria to incoming traffic without requiring continuous controller intervention or complex coordination with other devices during the forwarding process. This self-service approach ensures reliable traffic isolation while maintaining simple and independent device operation
Data Source
AI summary
An EVPN network device may advertise an EVPN IMET (type-3) route in a corresponding message to one or more peer EVPN network devices. The EVPN IMET route advertisement message may include an E-tree extended community indicating a leaf or root designation of a locally attached site at the advertising EVPN network device. The inclusion of the E-tree extended community in the EVPN IMET route advertisement message may provide desired traffic handling for implementing an EVPN E-tree service such as handling of BUM traffic.