Author: David Varnum

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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…)

Flowsim – A Web-based OpenFlow Learning Tool

Just discovered a tool developed by OpenFlow researchers and engineers called Flowsim. It’s been around for a couple of years, I’ve just never got around to using it. It’s a tool that helps you visually learn OpenFlow. It runs entirely in your browser, and all you need is a free account to get started.

You can configure OpenFlow switches and setup packets to be sent through the OpenFlow pipeline. If you’re curious about the underworkings of OpenFlow and don’t feel like setting up your own lab, definitely check it out. (more…)

OpenFlow – Basic Concepts and Theory

Spoken in the words of the Open Networking Foundation – one of the key concepts to understanding SDN is the separation of control plane and data plane. Typically a network is comprised of many routers and switches, each exchanging table information to build topologies. Each of these network devices has their own individualized control plane for brain-like functions such as route or MAC learning. Each network device also has its own data plane for forwarding packets. The challenge is each device has its own perspective of the network, and the only way you can view that perspective is by connecting to that device via a CLI and issue commands or configurations. The same is applicable for other devices like firewalls, load balancers, not just routers, and switches. (more…)

See in the Fog with Ixia CloudLens

Imagine looking up toward the sky on an average afternoon, marveling at the piercing blue background salted by white fluffy clouds. Each cloud is uniquely shaped, gloriously afloat, describable in terms even a five-year-old can understand. They look dense enough to stand on, soft enough to sleep on, and righteous enough to spend an afterlife walking among.

Now imagine riding passenger on a Boeing 747. You’re peering out the window as the aircraft takes off. As you ascend, steadily approaching the definitively shaped clouds, they curiously begin to lose shape and opacity. Enter the clouds — your perspective has significantly changed, for you can no longer see them for what they are. Rather, the sky is whitewashed and borderless. Oddly, you may still be able to see others in the distance, but you’re essentially blind to the cloud you’re in. Often times all you’ll see is the giant white soul of the cloud with no sky whatsoever, no coherent shape or texture. (more…)

Apstra intends greatness beyond Sparta

I swear it’s impossible to keep up with the networking industry. Just when I think I have it figured out, a technology hits the market that makes me rethink my life the past 10 years. It’s not fair! Apstra, a newer start-up company out of Silicon Valley, is guilty this time with their brilliant new approach to integrated closed-loop networking that will likely revolutionize the way we think about data center networks in the future. Like Spartans that followed a strict system emphasizing duty, discipline and endurance, Apstra is building structure and reason in a network of chaos. (more…)

Forward Networks – Extraordinary Stuff!

It’s not every day you see something that excites you to a point of ecstatic glee. This is a special day indeed, and it’s thanks to the minds at Forward Networks.

TL;DR, Forward Networks has introduced the first and only accurate software copy of your exact network. That’s right — a full-scale, veritable sandbox of your massive network, in a clean and powerful interface. No lie – it’s cool! (more…)

My thoughts on Paessler may surprise you

Ever hear of a company called Paessler AG? No? Neither have I. Ever hear of a product called PRTG? Of course?! Me too! Call me crazy, but I never knew this was the same company! Paessler AG presented for Tech Field Day at VMworld in Barcelona yesterday, demonstrating their product PRTG and making legitimate points in support of their competitive edge in the monitoring industry. In this blog I’ll be doing a personal Q&A about PRTG, running queries against the DB (Dave Brain), hoping it doesn’t fail on me. If it fails, I’m not too concerned, for I’ve installed the appropriate SNMP MIBs used to alert my right hand that coffee needs to be delivered to my mouth. PRTG, save me! (more…)

SolarWinds Orion API & SDK can do that?

My life was a one-track record on repeat, tirelessly playing the same tune over and over. New nodes added to the network means new nodes to monitor. The manual, arduous tasks of clicking through monitoring tool menus, selecting appropriate polling agents, configuring appropriate properties, and validating node status can lead a man to madness. There must be a better way!

When I first heard that I could “easily” script and automate some tasks in SolarWinds, I stared askance, knowing good and well this wouldn’t be easy, if it worked at all.  A couple of years later, and several hundred more managed nodes in the pocket,  I figured it’s time to revisit this possibility.  Although the SolarWinds Orion SDK has been around for a few years, documentation is limited and content is heavily reliant on the THWACK community.  However, dig deep enough, and you’ll find a wealth of useful information!  I learned that “easy” is relative, and given the number of examples SolarWinds provides in their SDK, it’s really not all that bad. (more…)

How writing has turned walls into windows

Those who have read my blog know that I am not a professional writer.  I’m a novice at best, blissfully blurting mediocre sentence structure in cyber space.  These words have never really been for anyone other than myself, so who cares if I’m overly generous with commas, or underwhelmingly inept with word diversity?  I mean, no one will ever be as critical as I am to myself.  This hasn’t stopped me.  In fact, I continue to write despite barriers and walls, for this has opened my mind far beyond what I could have imagined.  It’s all about the content. (more…)