Aliasing behavior for traffic to multihomed sites in ethernet virtual private network (evpn) networks

Abstract

For use in an Ethernet Virtual Private Network (EVPN) in which a site including at least one MAC-addressable device is multihomed, via a customer edge device (CE), to at least two provider edge devices (PEand PE), the potential problem of one of the at least two provider edge devices (PE) dropping or flooding packets designed for a MAC-addressable device of the multihomed site is solved by controlling advertisements of an auto-discovery per EVPN instance (A-D/EVI) route (or an auto-discovery per Ethernet segment identifier (A-D/ESI) route) to a remote provider edge device (PE), belonging to the EVPN but not directly connected with the CE. Such advertisements may be controlled by: (a) determining, by PE, whether or not a MAC-learning condition is met; and (b) responsive to a determination that the MAC-learning condition is met, advertising, by PE, an A-D/EVI route (or an A-D/ESI route) to the remote provider edge device (PE), and otherwise, responsive to a determination that the MAC-learning condition is not met, suppressing, by PE, an A-D/EVI route advertisement (or an A-D/ESI route advertisement).