EVPN/VXLAN replaced spanning-tree-centric designs in most modern data centers. It enables scalable spine-leaf fabrics, tenant isolation, and workload mobility — but shifts complexity from broadcast storms to BGP policy, ECMP behavior, and telemetry interpretation.
What changes operationally
- Control plane learning via BGP replaces flood-and-learn L2 behavior.
- East-west traffic uses ECMP — microbursts and hash polarization become visible problems.
- VNI allocation and IP fabric design require automation at scale.
- Troubleshooting moves from STP topology to EVPN routes, ARP suppression, and interface counters.
Evaluate refresh decisions carefully
Fabric choices persist for years. Size spines for burst tolerance, validate MTU end-to-end for overlays, and invest in telemetry before migration — not after the first production incident.