This is an example of multi-tenant DC network. The original design did use the VXLAN protocol to create several layer 2 virtual networks over a shared IPv6 DC fabric. This network features a Tenant DIF and a DC Fabric DIF. The later one allocates the resources in the leaf-spine fabric (between the TOR systems) to flows used by (potentially competing) Tenant DIFs, which provide isolated and customised networking domains to each DC tenant and its VM.