Work out how much of the 16.7 million VNI space a multi-tenant VXLAN design consumes.
VXLAN replaces the 4094 usable VLAN IDs with a 24-bit identifier, giving 16.7 million segments. Each tenant consumes one VNI per L2 segment plus one per routed VRF, and infrastructure VNIs are normally carved out of a reserved block. The VNI space is effectively unlimited, but the practical limits — VNIs per switch ASIC and per EVPN control plane — are much lower, so the real value is knowing the design's shape before you hit a platform ceiling.
VXLAN VNI
VXLAN carries a 24-bit VNI, so the space is 2^24 = 16 777 216; VNIs required = tenants × (L2 segments + L3 VNIs).
VXLAN carries a 24-bit VNI, so the space is 2^24 = 16 777 216; VNIs required = tenants × (L2 segments + L3 VNIs). VXLAN replaces the 4094 usable VLAN IDs with a 24-bit identifier, giving 16.7 million segments. Each tenant consumes one VNI per L2 segment plus one per routed VRF, and infrastructure VNIs are normally carved out of a reserved block.
The VNI space is effectively unlimited, but the practical limits — VNIs per switch ASIC and per EVPN control plane — are much lower, so the real value is knowing the design's shape before you hit a platform ceiling.
This calculator takes 4 inputs: Tenants, L2 segments per tenant, L3 VNIs per tenant (VRFs), VNIs reserved for infrastructure. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.