In May 2015 I invited Dinesh Dutt to talk about Cumulus Linux and its typical use cases on an update session of the Data Center Fabrics Architecture webinar.

As expected, he started with the big picture: what are Cumulus Networks and Cumulus Linux all about?

It’s hard to visit an IT journal web site without stumbling upon an SDN fairy tale. Here’s another one:

The idea is to cut away the manual process of setting up new firewalls, load balancers and other network appliances, and instead open the door to provisioning a new network infrastructure within a few minutes.

And why exactly is it that you can’t do that today?

35 years ago, mainframes, single-protocol networks (be it SNA or DECnet), and centralized architectures that would make hard-core SDN evangelists gloat with unbridled pride were all the rage. If you’re old enough to remember IBM SNA, you know what I’m talking about.

A few years later, everything changed.

I published the second part of my Designing Scalable Web Applications course on my free content web site.

These presentations focus more on the application-level technologies (client- and server side), but I’m positive you’ll find some useful content in the caching and scale-out applications with load balancing sections.

Gartner has updated their networking hype cycle. Not surprisingly:

• Ethernet switching fabrics are on the slope of enlightenment (finally – we’ve been educating networking engineers on what they really are for half a decade);
• SDN is well on its way into the trough of disillusionment (shameless plug: I guess not enough people attended real-life SDN workshops) and whitebox switching is going the same way;
• SD-WAN is nearing the peak of inflated expectations;
• FCoE and Long-Distance vMotion will be dead before they reach the plateau.

Gartner won’t give you free access to the graph, but you’ll find it in an article published on The Register.

One of the participants of the Carrier Ethernet LinkedIn group asked a great question:

When we install a virtual-router of any vendor over an ordinary sever (having general-purpose microprocessor), can it really compete with a physical-router having ASICs, Network Processors…?

Short answer: No … and here’s my longer answer (cross-posted to my blog because not all of my readers participate in that group).

Like all other ipSpace.net webinars, the IPv6 Microsegmentation webinar starts with a brief description of the problem we’re trying to solve: the IPv6 first-hop security challenges.

For an overview of this problem, watch this free video from the IPv6 microsegmentation webinar, for more details, watch the IPv6 Security webinar.

Matt Oswalt wrote a great blog post complaining about vendors launching ocean-boiling solutions instead of focused reusable components, and one of the comments his opinion generated was along the lines of “I thought one of the reasons people wanted SDN, is because they wanted to deal with The Network – think about The Network's Performance, Robustness and Services instead of dealing with 100s or 1000s of individual boxes.”

The comment is obviously totally valid, so let me try to reiterate what Matt wrote using Lego bricks ;)

Last week I published slide decks for Network Function Virtualization, BGP-Based SDN Solutions and SDN Use Cases webinars – they’re available to subscribers and attendees registered for individual webinars.

Content from all three webinars is part of my SDN workshop – if you’d like to hear a live explanation, register for one of them.

A recent well-publicized network outage prompted someone to start collecting fat-finger horror stories, and dozens of networking engineers were quick to chime in. Enjoy!

My Business Case for SD-WAN blog post received numerous comments pointing out the potential pitfalls of hybrid WAN, including reduced security, unreliable Internet services and denial-of-service attacks.

While all those comments are perfectly valid, I still think hybrid WAN (whether implemented with traditional technologies or SD-WAN products) makes perfect sense.

I found a great explanation for hodgepodge of kludges found in "organically grown" solutions (legacy precursors to SD-WAN come to mind):

In a long-lived project, components are being replaced. Nice reusable components are easy to replace and so they are. Ugly non-reusable components are pain to replace and each replacement means both a considerable risk and considerable cost. Thus, more often then not, they are not replaced. As the years go by, reusable components pass away and only the hairy ones remain. In the end the project turns into a monolithic cluster of ugly components melted one into another.

Note: You really should read the whole blog post.

Most people casually involved with virtual appliances and network function virtualization (NFV) believe that replacing Linux TCP/IP stack with user-mode packet forwarding (example: Intel’s DPDK) boosts performance from meager 1 Gbps to tens of gigabits (and thus makes hardware forwarding obsolete).

Having data points is always better than having opinions; today let’s look at Receiving 1 Mpps with Linux TCP/IP Stack blog post.

2015-07-18: The blog post was updated based on feedback by Kristian Larsson.

It's so nice to see someone saying eloquently what you've been trying to say for a while – you (RFC 2119) MUST read what my friend Matt Oswalt wrote about Big Flowering Things.