Deployment Guide
Table Of Contents
- 1 Introduction
- 2 Hardware overview
- 3 Leaf-spine overview
- 4 Protocols used in the leaf-spine examples
- 5 Layer 3 configuration planning
- 6 Example 1: Layer 3 with Dell EMC leaf and spine switches using OSPF
- 7 Example 2: Layer 3 with Dell EMC leaf and spine switches using eBGP
- A Dell EMC Networking ONIE switch factory default settings
- B Validated hardware and operating systems
- C Technical support and resources
- D Support and Feedback
12 Dell EMC Networking Layer 3 Leaf-Spine Deployment and Best Practices with OS10 | Version 1.0
Internal Use - Confidential
4.7 Equal Cost Multi-Path (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 8, Leaf 1 has two equal cost paths to Leaf 4, one through each spine. The same is true for all
leaf switches.
Rack 2Rack 1
Leaf 4
Spine 1 Spine 2
Leaf 3
Leaf 2
Leaf 1
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 leaf
switches to be load balanced across the spine switches.