Overlay Virtual Networks in Software Defined Data Centers

The second digital book in the Software Defined Networking series describes the overlay virtual networking principles, architectures, solutions, and their applications in software-defined data centers (SDDC).

The book is available in DRM-free watermarked PDF format.

More about the book

Until Cisco launched VXLAN in 2011, server virtualization vendors used VLANs to create virtual subnets between virtual machines, resulting in rigid architectures with tight coupling between hypervisor virtual switches and adjacent physical switches. The rigidity of the resulting architecture and VLAN scalability problems significantly hamper operational efficiency, resulting in a flurry of overlay virtual networking products that transport VM-level payloads across IP infrastructure.

The responses of the traditional networking engineers was easy to predict:

• Overlay virtual networking is nothing more than tunnels in disguise;
• Tunnels are complex and hard to provision;
• We’ll lose QoS and end-to-end visibility.

It took years to debunk some of these misconceptions and prove that the overlay virtual networks make architectural sense (and even today you can see the raging debates between proponents of hardware-based network virtualization products and overlay virtual networking products). In these years I wrote over fifty blog posts explaining the architectural details of overlay virtual networks, design guidelines, and product details.

This book contains a collection of the most relevant blog posts describing overlay virtual networking concepts, benefits and drawbacks, architectures, technical details and individual products. I cleaned up the blog posts and corrected obvious errors and omissions, but also tried to leave most of the content intact. The commentaries between the individual blog posts will help you understand the timeline or the context in which a particular blog post was written.

Contents

The book covers these topics:

• Introduction to overlay virtual networking concepts and architectures (Chapter 1);
• Overlay virtual networking technical details (Chapter 2);
• Product details, covering Cisco Nexus 1000V, VMware NSX, Microsoft Hyper-V network virtualization and a few smaller vendors (Chapter 3);
• Gateways between overlay virtual networks and physical networks (Chapter 4);
• Challenges of long-distance overlay virtual networks (Chapter 5);
• My opinions on alternate approaches to network virtualization (Chapter 6);

Happy Campers