Spine-leaf architecture
What is spine-leaf architecture?

A spine-leaf architecture is data center network topology that consists of two switching layers—a spine and leaf. The leaf layer consists of access switches that aggregate traffic from servers and connect directly into the spine or network core. Spine switches interconnect all leaf switches in a full-mesh topology.

Aerial view of an open floor office.
  • How does a spine-leaf architecture differ from traditional network designs?
  • Why are spine-leaf architectures becoming more popular?
  • Building a spine-leaf architecture with HPE Aruba Networking CX Switching
How does a spine-leaf architecture differ from traditional network designs?

How does a spine-leaf architecture differ from traditional network designs?

Traditionally, data center networks were based on a three-tier model:

  • Access switches connect to servers
  • Aggregation or distribution switches provide redundant connections to access switches
  • Core switches provide fast transport between aggregation switches, typically connected in a redundant pair for high availability

At the most basic level, a spine-leaf architecture collapses one of these tiers, as depicted in these diagrams.

Other common differences in spine-leaf topologies include:

  • The removal of Spanning Tree Protocol (STP)
  • Increased use of fixed port switches over modular models for the network backbone
  • More cabling to purchase and manage, given the higher interconnection count
  • A scale-out vs. scale-up of infrastructure
2-tier and 3-tier spine-leaf architecture.

Related topics

What is network switch?

What is data center networking?

What is PoE switch (Power over Ethernet switch)?