2.2.3. Spine-Leaf

Optimized for data centers where traffic is predominantly east-west (server-to-server) rather than north-south (client-to-server).

Characteristics:

• Every leaf connects to every spine; spines never link to other spines and leaves never link to other leaves (endpoints attach only to leaves)
• Consistent hop count between any two servers: traffic between two leaves always crosses exactly one spine (leaf–spine–leaf)
• No Spanning Tree (uses ECMP routing)
• Scales horizontally by adding leaves or spines