Abstract
The present disclosure describes a method for selectively suppressing Ethernet Virtual Private Network (EVPN) route advertisements (specifically Route Types RT1, RT2, and RT3) during Route Target (RT) mismatches in EVPN multihomed topologies employing Route Target Constraints (RTC). The method involves differentiating RT advertisements based on Ethernet Segment (ES) identifiers by including ES extended community information within RTC updates. Upon detecting RT mismatches between multihomed Provider Edge (PE) routers, selective suppression is applied exclusively to certain non-essential EVPN routes (RT1 with VLAN tags, RT2 MAC/IP advertisements, and RT3 Inclusive Multicast routes). Critical EVPN routes necessary for Designated Forwarder (DF) election, aliasing, and mass withdrawal (RT1 Ethernet Auto-Discovery per ES, RT1 Ethernet Auto-Discovery per EVI, and RT4 Ethernet Segment routes) remain unaffected and continue normal propagation. This selective suppression mechanism reduces unnecessary BGP updates, optimizes CPU and memory utilization in large-scale EVPN deployments, and improves network stability and efficiency. Additionally, the disclosure introduces a new RTC capability within BGP that allows routers to negotiate support for this optimized route suppression approach.
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.
Recommended Citation
Anonymous, "Selectively Suppress EVPN Routes (RT1, RT2 & RT3) during RT Mismatch in EVPN Multihomed Topology with RTC", Technical Disclosure Commons, (July 09, 2025)
https://www.tdcommons.org/dpubs_series/8331