Question

A service provider deploys EVPN with a dual-homed CE connected to two PE routers (PE1 and PE2) using the same Ethernet Segment Identifier (ESI) in all-active redundancy mode. Remote PE3 learns a customer MAC address via an EVPN Type 2 route advertised only by PE1. Operators observe that PE3 load-balances traffic toward the CE across both PE1 and PE2, even though only PE1 advertised the MAC. Which EVPN mechanism enables PE3 to forward toward PE2 for a MAC it never received from PE2?

Accepted Answer

The EVPN Type 1 (Ethernet Auto-Discovery per-ES/per-EVI) route combined with aliasing allows PE3 to install both PE1 and PE2 as valid next hops for MACs reachable via the shared ESI.

Answer

The EVPN Type 3 (Inclusive Multicast Ethernet Tag) route signals BUM replication, enabling PE3 to unicast the MAC to both PEs.

Answer

MAC mobility extended community on the Type 2 route instructs PE3 to duplicate the MAC entry toward both PE1 and PE2.

Answer

The Type 4 (Ethernet Segment) route performs designated forwarder election, which forces PE3 to hash flows across all PEs in the segment.