Ethernet Segment Redundancy Mode
Ethernet Segments (ES) can be configured
to operate in all-active or single-active mode for a Layer 2 Virtual Private Network
(L2VPN)
using Ethernet Virtual Private Network (EVPN).
When all-active mode is configured for an ES, the ES is simultaneously UP on all member VTEPs. Traffic is distributed across all VTEPs, providing load balancing and redundancy. All-active mode is most commonly used in a multihoming environment.
When single-active mode is configured for an ES, the ES is physically UP on only one member VTEP at a time and is DOWN on the other member VTEPs. If the ES goes down on the current active VTEP, another member VTEP becomes active and brings the ES UP. This operational state applies to the entire ES for all member VLANs.