Designing Leaf-and-Spine Fabrics Workshop » Workshops » Designing Leaf-and-Spine Fabrics Workshop

Every data center switching vendor is telling you that leaf-and-spine fabrics are the way to go, and the sales process often focuses only on the required bandwidth and port counts… but unless you’re buying a fully integrated black box (example: Cisco ACI), someone has to design the layer-2 and layer-3 aspects of the fabric.

This vendor-independent workshop will:

  • Explain the basics of leaf-and-spine fabrics, including ECMP load balancing and oversubscription ratios;
  • Help you design your data center fabric regardless of whether you need a layer-2 (VLAN) or layer-3 (routed) solution;
  • Give you design guidelines ranging from small (two switches) to very large (hundreds of switches) fabrics.


  • Designing Leaf-and-Spine Fabrics is a ½ day intensive instructor-led on-site workshop;
  • Contact us for more details or if you want to have a customized on-site workshop for a closed group of up to 20 attendees

Topics Covered

The workshop covers these topics:

  • Introduction to leaf-and-spine architectures;
  • Layer-3 designs;
  • Layer-2 designs;
  • Mixed layer-2 + layer-3 designs.

Introduction to Leaf-and-Spine Architectures

  • Leaf-Spine (or Clos) architectures
  • Multi-stage leaf-and-spine fabrics
  • Leaf-and-spine design process
  • Deployment considerations

Layer-3 Designs

  • Non-redundant and redundant layer-3-only designs
  • Routing protocol selection
  • Core (leaf-to-spine) link addressing and unnumbered interfaces
  • BGP and OSPF design and implementation details

Layer-2 Designs

  • Simple layer-2-only designs using either MLAG or layer-2 fabric technologies
  • Layer-2 designs with redundant server connectivity
  • Implementation of layer-2 fabrics with overlay virtual networking

Mixed Layer-2 + Layer-3 Designs

This section builds on the principles introduced in layer-2 designs and layer-3 designs and describes these typical scenarios:

  • Routing on a single spine switch
  • Routing on multiple spine switches (multiple active default gateways)
  • Anycast spine routing implementation in SPB or TRILL
  • Anycast leaf gateways
  • Anycast leaf gateways using overlay transport across fabric core
  • Layer-3-only fabrics implemented with routed core or overlay transport.

Technical Deep Dives

Workshop attendees get access to Leaf-and-Spine Fabric Architectures webinar which includes nine hours of downloadable videos covering the topics described in the workshop as well as:

  • BGP enhancements in data center fabrics by Dinesh Dutt (Cumulus Networks);
  • Layer-3-only data centers with host routing (Dinesh Dutt)
  • Routing on hosts (Dinesh Dutt)
  • Shortest Path Bridging technology deep dive by Roger Lapuh (Avaya)
  • VXLAN with EVPN control plane by Lukas Krattiger (Cisco Systems)


After attending this workshop you'll be able to:

  • Design physical connectivity in leaf-and-spine fabric;
  • Select the hardware used for leaf and spine switches;
  • Design IP addressing and select the best IP routing protocol for your fabric;
  • Design layer-2 transport across the fabric using layer-2 technologies (MLAG, TRILL or SPB) or VXLAN encapsulation;
  • Create mixed layer-2 / layer-3 fabrics.

Who Should Attend

This workshop targets architects and designers who are planning, designing or building next-generation data center fabrics.

About the Author

Ivan PepelnjakIvan Pepelnjak, CCIE#1354 Emeritus, is an independent network architect, book author, blogger and regular speaker at industry events like Interop, RIPE and regional NOG meetings. He has been designing and implementing large-scale service provider and enterprise networks since 1990, and is currently using his expertise to help multinational enterprises and large cloud- and service providers design next-generation data center and cloud infrastructure using Software-Defined Networking (SDN) and Network Function Virtualization (NFV) approaches and technologies.

Ivan is the author of several books covering data center technologies, highly praised webinars, and dozens of data center and cloud-related technical articles published on his blog.

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