The Hedge 37: Stephane Bortzmeyer and DNS Privacy
In this episode of the Hedge, Stephane Bortzmeyer joins Alvaro Retana and Russ White to discuss draft-ietf-dprive-rfc7626-bis, which “describes the privacy issues associated with the use of the DNS by Internet users.” Not many network engineers think about the privacy implications of DNS, a important part of the infrastructure we all rely on to make the Internet work.
Ruminating on SOS
Many years ago I attended a presentation by Dave Meyers on network complexity—which set off an entire line of thinking about how we build networks that are just too complex. While it might be interesting to dive into our motivations for building networks that are just too complex, I starting thinking about how to classify and understand the complexity I was seeing in all the networks I touched. Of course, my primary interest is in how to build networks that are less complex, rather than just understanding complexity…
This led me to do a lot of reading, write some drafts, and then write a book. During this process, I ended coining what I call the complexity triad—State, Optimization, and Surface. If you read the book on complexity, you can see my views on what the triad consisted of changed through in the writing—I started out with volume (of state), speed (of state), and optimization. Somehow, though, interaction surfaces need to play a role in the complexity puzzle.
The Hedge 36: Rich Alderson and the Living Computer History Museum
The Living Computers History Museum and Labs was founding by Paul Allen to collect early computer systems and keep the constrained resource coding practices used on these systems alive. Over time it has developed into a living museum and lab, with hands-on access to some of the earliest examples of computing history. Rich Alderson joins us for this episode of the Hedge to describe the museum and its exhibits.
Learning from the Post-Mortem
Post-mortem reviews seem to be quite common in the software engineering and application development sides of the IT world—but I do not recall a lot of post-mortems in network engineering across my 30 years. This puzzling observation sprang to mind while I was reading a post over at the ACM this last week about how to effectively learn from the post-mortem exercise.
The common pattern seems to be setting aside a one hour meeting, inviting a lot of people, trying to shift blame while not actually saying you are shifting blame (because we are all supposed to live in a blame-free environment now—fix the problem, not the blame!), and then … a list is created on a whiteboard, pictures are taken, and everyone walks away with a rock-solid plan to never do that again.
The Hedge 35: Peter Jones and Single Pair Ethernet
When you think of new Ethernet standards, you probably think about faster and optical. There is, however, an entire world of buildings out there with older copper cabling, particularly in the industrial realm, that could see dramatic improvements in productivity if their control and monitoring systems could be moved to IP. In these cases, what is needed is an Ethernet standard that runs over a single copper pair, and yet offers enough speed to support industrial use cases. Peter Jones joins Jeremy Filliben and Russ White to discuss single pair Ethernet.
Understanding DC Fabric Complexity
When I think of complexity, I mostly consider transport protocols and control planes—probably because I have largely worked in these areas from the very beginning of my career in network engineering. Complexity, however, is present in every layer of the networking stack, all the way down to the physical. I recently ran across an interesting paper on complexity in another part of the network I had not really thought about before: the physical plant of a data center fabric.
Quitting Certifications: When?
At what point in your career do you stop working towards new certifications?
Daniel Dibb’s recent post on his blog is, I think, an excellent starting point, but I wanted to add a few additional thoughts to the answer he gives there.
Daniel’s first question is how do you learn? Certifications often represent a body of knowledge people who have a lot of experience believe is important, so they often represent a good guided path to holistically approaching a new body of knowledge. In the professional learning world this would be called a ready-made mental map. There is a counterargument here—certifications are often created by vendors as a marketing tool, rather than as something purely designed for the betterment of the community, or the dissemination of knowledge. This doesn’t mean, however, that certifications are “evil.” It just means you need to evaluate each certification on its own merits.
The Hedge 33: Balazs Varga and DETNET
Balazs Varge joins Alvaro Retana and Russ White on this episode of the Hedge to discuss the working going on in the IETF around deterministic networking. This work is important for applications requiring networks providing low latency and loss.
The Resilience Problem
This quote set me to thinking about how efficiency and resilience might interact, or trade off against one another, in networks. The most obvious extreme cases are two routers connected via a single long-haul link and the highly parallel data center fabrics we build today. Obviously adding a second long-haul link would improve resilience—but at what cost in terms of efficiency? Its also obvious highly meshed data center fabrics have plenty of resilience—and yet they still sometimes fail. Why?