The existing production topology without SmartFabric Services (SFS) used to develop this guide is described in this section. A multi-rack environment is used, but it also applies to single-rack deployments. All switches are in full switch mode in the existing topology.
Uplinks to external switches can be Layer 2 or Layer 3. Layer 2 is used for the example in this guide.
Two leaf switches are used in each rack for redundancy and performance. A Virtual-Link Trunking interconnect (VLTi) connects each pair of leaf switches.
Four ESXi servers are installed in two racks and are configured in a vSphere cluster.
Later in this guide, the same leaf-spine fabric that is shown above is converted to SFS.