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

A non-transitory computer-readable storage medium having stored thereon, processor-executable instructions which, when executed by at least one processors, cause the at least one processor to perform a method for use in an Ethernet Virtual Private Network (EVPN) in which a customer site including at least one MAC-addressable device is multihomed, via a customer edge device (CE), to at least two provider edge devices (PE1 and PE2), a computer-implemented method for controlling EVPN aliasing-based 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 (PE3), belonging to the EVPN but not directly connected with the CE, such that the probability of one of the at least two provider edge devices (PE2) dropping or flooding packets designed for a MAC-addressable device of the multihomed site is reduced, the method comprising:

• a) determining, by the one of the at least two provider edge devices (PE2), whether or not a MAC-learning condition is met;
• and
• b) responsive to a determination that the MAC-learning condition is met,
• performing EVPN aliasing-based advertising, by the one of the at least two provider edge devices (PE2), of an A-D/EVI route or an A-D/ESI route to the remote provide edge device (PE3), and
• otherwise, responsive to a determination that the MAC-learning condition is not met,
• suppressing, by the one of the at least two provider edge devices (PE2), an A-D/EVI route advertisement or an A-D/ESI route advertisement that would otherwise occur due to EVPN aliasing, such that the remote provider edge device (PE3) does not assume that the customer edge device (CE) is reachable via the one of the at least two provider edge devices (PE2).

A provider edge device for use in an Ethernet Virtual Private Network (EVPN) in which a customer site including at least one MAC-addressable device is multihomed, via a customer edge device (CE), to the provider edge device and at least one other provider edge device, the provider edge device comprising:

• a) a forwarding component for forwarding data packets to and from the customer site;
• and
• b) a control component for controlling EVPN aliasing-based 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 (PE3), belonging to the EVPN but not directly connected with the CE, such that the probability of one of the at least two provider edge devices (PE2) dropping or flooding packets designed for a MAC-addressable device of the multihomed site is reduced, the control component being configured to:
• 1) determine whether or not a MAC-learning condition is met;
• and
• 2) responsive to a determination that the MAC-learning condition is met,
• perform EVPN aliasing-based advertising of an A-D/EVI route or an A-D/ESI route to the remote provide edge device (PE3), and
• otherwise, responsive to a determination that the MAC-learning condition is not met,
• suppress an A-D/EVI route advertisement or an A-D/ESI route advertisement that would otherwise occur due to EVPN aliasing, such that the remote provider edge device (PE3) does not assume that the customer edge device (CE) is reachable via the one of the at least two provider edge devices (PE2).