Abstract
A method and system for proactive Make-Before-Break (MBB) traffic protection in an Ethernet Virtual Private Network (EVPN) is disclosed. A first Provider Edge (PE) router monitors a physical-layer Bit Error Rate (BER) on a link to a multi-homed Customer Edge (CE) device. When the measured BER crosses a configurable threshold while the link remains operationally up, the first PE router originates a Border Gateway Protocol (BGP) UPDATE carrying a new transitive Extended Community that signals link degradation, the BGP UPDATE being attached to an EVPN Type 1 Ethernet Auto-Discovery per-Ethernet Segment route. Remote PE routers receiving the Extended Community migrate traffic destined for the CE device away from the degrading link to an alternate PE router in a single forwarding operation, before the degrading link fails. A subsequent mass withdrawal upon link failure causes no additional forwarding change and zero packet loss, and traffic is rebalanced when the link recovers.
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.
Recommended Citation
Anonymous, "Proactive Make-Before-Break Traffic Steering in EVPN Multi-Homing Using a BGP Extended Community for Pre-Failure Link Degradation Signaling", Technical Disclosure Commons, (July 07, 2026)
https://www.tdcommons.org/dpubs_series/10824