Ivan Pepelnjak

Author Archives: Ivan Pepelnjak

IPv6 and the Swinging Technology Pendulum

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.

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SDN, SD-WAN and FCoE on Gartner Networking Hype Cycle

Gartner has updated their networking hype cycle. Not surprisingly:

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

Can Virtual Routers Compete with Physical Hardware?

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).

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Big Flowering Things and Lego Bricks

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 ;)

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Explaining the Pervasive Kludgeitis

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.

Can You Avoid Networking Software Bugs?

One of my readers sent me an interesting reliability design question. It all started with a catastrophic WAN failure:

Once a particular volume of encrypted traffic was reached the data center WAN edge router crashed, and then the backup router took over, which also crashed. The traffic then failed over to the second DC, and you can guess what happened then...

Obviously they’re now trying to redesign the network to avoid such failures.

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Why Should I Care About Networking?

A month ago I was asked to deliver a short presentation on “something interesting about networking” at my local university. The temptation to talk about network automation and SDN was huge, but I quickly figured out that would make no sense (the audience were students in their freshman year) and decided to talk about a fundamental question: why should a programmer care about networking.

Unfortunately the presentation wasn’t recorded, but you can browse the slide deck on the ipSpace.net public content web site.

Some Ridiculous SD-WAN Claims

SDx Central is usually a pretty good web site that I love to read, but even they occasionally manage to publish a gem like this one:

The problem with MPLS and similar technologies is that they weren’t designed with today’s business challenges in mind. Today, a company may need to launch an overseas R&D office overnight, or it may acquire a startup and want to immediately network with offices in distant regions and countries. Older technologies just don’t have the flexibility to do this on the fly.

Not surprisingly, the above paragraph triggered a severe case of Deja-Moo.

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