Deployment Guide

16 Leaf-Spine Deployment and Best Practices Guide | Version 1.0
5.6 ECMP
The nature of a leaf-spine topology is that leaf switches are no more than one hop away from each other. As
shown in Figure 10, Leaf 1 has two equal cost paths to Leaf 4, one through each spine. The same is true for
all leafs.
Rack 2
Rack 1
Leaf 4
Spine 1 Spine 2
Leaf 3
VLTi
Leaf 2
Leaf 1
VLTi
ECMP
Path 2
Path 1
Use of ECMP in a layer 3 topology
ECMP is a routing technique used in a layer 3 leaf-spine topology for load balancing packets along these
multiple equal cost paths. ECMP is enabled on all leaf and spine switches, allowing traffic between leafs to be
load balanced across the spines.