4.2.2 Leaf-and-Spine Fabric Design
The evolution of the leaf-and-spine design evolved based on the following requirements:
• Addressing the increasing demand of traffic for East-West communication
• Ability to deploy applications independent of the Layer 2 fabric within each Pod
Figure 7. Leaf-Spine Fabric Design
The evolved leaf-and-spine design also collapsed the number of networking layers from three logical layers (core/aggregation/access) to two logical layers (leaf-spine).
Note A border leaf is a special leaf node that supports the external connection to the WAN or Internet.
As mentioned in the VMware NSX for vSphere (NSX-V) Network Virtualization Design Guide., the following topics must be considered when defining the end-to-end network requirements:
• Simplicity
• Scalability
• High-bandwidth
• Fault-tolerance
• Quality of Service (QoS)
This document provides further detail to these areas of focus.
