You designed a network with dual data centers that are connected to each other using a MPLS Layer 3 VPN service. These data centers require a Layer 2 connection between two application servers, one…

An Ethernet Virtual Private Line (EVPL) is a MEF-defined Layer 2 WAN service that transparently extends an Ethernet segment between two sites, directly satisfying the requirement for server-to-server L2 adjacency across geographically separated data centers.

Ethernet over MPLS (EoMPLS) is provisioned between PE routers within the provider network, not between CE routers, so it does not represent a CE-to-CE overlay solution within an existing L3 VPN topology.

A VLAN between CE and PE creates a local L2 segment on the CE-PE access link only and does not extend Layer 2 connectivity end-to-end between the two data centers.

L2TPv3 creates a pseudowire tunnel between CE routers over the existing IP/MPLS backbone, encapsulating Layer 2 Ethernet frames end-to-end and providing the required L2 connectivity between servers at different data centers without modifying the underlying L3 VPN infrastructure.

Multi-VRF on CE routers is a Layer 3 VPN segmentation technique for traffic isolation and does not provide the Layer 2 adjacency required between the application servers.