A leaf-and-spine network is the core building block for the physical network in the SDDC.
A leaf switch is typically located inside a rack and provides network access to the servers inside that rack, it is also referred to as a Top of Rack (ToR) switch.
A spine switch is in the spine layer and provides connectivity between racks. Links between spine switches are typically not required. If a link failure occurs between a spine switch and a leaf switch, the routing protocol ensures that no traffic for the affected rack is sent to the spine switch that has lost connectivity to that rack.
Ports that face the servers inside a rack should have a minimal configuration, shown in the following high-level physical and logical representation of the leaf node.
Each leaf node has identical VLAN configuration with unique /24 subnets assigned to each VLAN.