Author: David Varnum


Arista BGP EVPN – Overview and Concepts


Traditionally, Data Centers used lots of Layer 2 links that spanned entire racks, rows, cages, floors, for as far as the eye could see. These large L2 domains were not ideal for a data center, due to the slow convergence, unnecessary broadcasts, and difficulty in administering. To optimize the data center network, we needed to reduce the use of and reliance on layer 2 protocols such as Spanning Tree. The challenge, however, is the fact that Data Centers need Layer 2 stretching from rack to rack, row to row, sometimes from data center to data center, not only for application requirements but also for fault tolerance and workload mobility. Numerous technologies have come forth to battle this limitation, such as TRILL, FabricPath, and VXLAN. Of these three, it is Virtual Extensible LAN (VXLAN) that has seen rapid adoption in modern data centers. (more…)

Leveraging SD-WAN for Mergers & Acquisitions

A colleague recently asked me if SD-WAN could be leveraged to expedite network integration as a result of a merger or acquisition. His thoughts were that this could potentially provide a means to securely integration networks in a short amount of time.  At first I thought this made no sense — SD-WAN is not related to this challenge whatsoever. However, the idea stuck in my head like a bad catchy tune. I started thinking… maybe in certain circumstances this could work?  This post is a collection of some ideas I’ve been brewing with respect to the secure and timely integration of disparate networks using over-the-counter SD-WAN. (more…)

ONF Certified SDN Associate (OCSA) – Part 1

The concept of SDN is constantly evolving. There are countless adaptations, projects, solutions, and products in this market, and we’ve just begun to see the impact. Developed network engineers will want to stay informed in this age of great change. This is why the Open Networking Foundation (ONF) put together a certification program for SDN. (more…)