Author: David Varnum


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…)