I hate listening to “this is what we were doing this year” podcasts as they usually turn into pointless blabbering, self-congratulations and meaningless plans (think New Year resolutions). The Full Stack Journey Episode 28 with Scott Lowe was an amazing deviation from this too-common template.

If you don’t have time to listen to the podcast (but you OUGHT TO do it) here’s what I loved most: “When faced with the onslaught of new technologies, don’t panic. Wait a few months to see which ones survive”.

TL&DR: MIA

Six years ago, when I was talking about overlay virtual networks at Interop, I loved to joke that we must be living on a weird planet where Microsoft has the best overlay virtual networking implementation… at least as far as IPv6 goes.

Even then, their data plane implementation which was fully dual-stack-aware on both tenant- and underlay level was way ahead of what System Center could do.

Last week I explained how you could take a typical first attempt at a network automation data model and reduce the amount of duplicate data… but the data model we used was still describing a set of seemingly disconnected boxes.

How about restructuring the whole thing and describing what networks really are - graphs made of nodes (network devices) and links?

More than a decade ago I decided to start a pet project: a blog describing interesting details of networking technologies. The idea quickly morphed into vendor-neutral webinars - the first one took place in February 2010. A year or two later I had my first guest speaker and as of today we had more than 50 industry experts participating in ipSpace.net webinars and online courses.

In the meantime the ipSpace.net team grew: I had video and audio editors for years, Irena Marčetič took over marketing, logistics, and production in 2018, and we got a team of webinar moderators that will help us with guest speaker webinars (last week we ran the first guest speaker webinar where I didn’t have to be involved - hooray ;)

Kate Matsudaira wrote a nice article explaining how to deal with emotional attachment to a project you spent a lot of time working on. While she's focusing on software development, the same fallacies apply to networking - sometimes it's time to let the old pile of **** die and replace it with something created in this decade.

A few years ago we “celebrated” 512K day - the size of the full Internet routing table exceeded 512K (for whatever value of K ;) prefixes, overflowing TCAMs in some IP routers and resulting in interesting brownouts.

We’re close to exceeding 768K mark and the beware 768K day blog posts have already started appearing. While you (RFC 2119) SHOULD check the size of your forwarding table and the maximum capabilities of your hardware, the more important question should be “Why do I need 768K forwarding entries if I’m not a Tier-1 provider”

This blog post was initially sent to subscribers of my SDN and Network Automation mailing list. Subscribe here.

Remember the “every device configuration is really an expression of our intent” discussion? Forgetting the wrong level of abstraction (we mostly don’t want to deal with all the idiosyncratic stuff network devices want to see in their configurations) and box-oriented thinking caused by device-level intent for the moment, let’s focus on another aspect: how hard is it to manage your intent?

Remember how Arista promoted VXLAN coupled with deep buffer switches as the perfect DCI solution a few years ago? Someone took Arista’s marketing too literally, ran with the idea and combined VXLAN-based DCI with traditional MLAG+STP data center fabric.

While I love that they wrote a blog post documenting their experience (if only more people would do that), it doesn’t change the fact that the design contains the worst of both worlds.

Here are just a few things that went wrong:

One of the toughest challenges in the hands-on part of Building Network Automation Solutions online course is the create a data model describing your service exercise.

Networking engineers never had to think about data models describing their networks or services, and the first attempt often results in something that looks like simplified device configuration in YAML or JSON format.

I wrote a long article describing how you can slowly redesign your box-focused data model into a network-focused one. The first parts describing the problem and initial deduplication are already online.

After a few weeks of venting my frustrations on Twitter I finally completed Microsoft Azure Networking slide deck last week and published the related demos on GitHub.

I will use the slide deck in a day-long workshop in Zurich (Switzerland) on June 12^th and run a series of live webinar sessions in autumn. If you’re a (paid) subscriber you can already download the slides and it would be great if you’d have time to attend the Zurich workshop – it’s infinitely better to discuss interesting challenges face-to-face than to type questions in a virtual classroom.

Every time a new simple programming language is invented, we go through the same predictable cycle:

• Tons of hype;
• Unbounded enthusiasm when people who never worked in target environment realize they could get something simple done in a short time;
• Ever-worsening headaches as the enthusiasts try to get a real job done with the shiny new tool;
• Disappointment;
• A more powerful language is invented to replace the old one.

A few years ago we experienced the same cycle when OpenFlow was the-one-tool-to-bind-them all.

This blog post was initially sent to subscribers of my SDN and Network Automation mailing list. Subscribe here.

Imagine a small bank deciding in their infinite wisdom (in reality: because their CIO attended a conference organized by a database vendor) to implement their banking software by teaching bank tellers how to type SQL transactions by hand.

For example, to transfer money from one account to another account, a bank teller could simply type:

Russ White recently wrote an interesting blog post claiming how we should not ignore any particular technology just because it was invented by a hyperscaler illustrating his point with a half-dozen technologies that were first used by NASA.

However, there are “a few” details he glossed over:

An attendee in my Building Next-Generation Data Center online course was asked to deploy numerous relatively small OpenStack cloud instances and wanted select the optimum virtual networking technology. Not surprisingly, every $vendor had just the right answer, including Arista:

We’re considering moving from hypervisor-based overlays to ToR-based overlays using Arista’s CVX for approximately 2000 VLANs.

As I explained in Overlay Virtual Networking, Networking in Private and Public Clouds and Designing Private Cloud Infrastructure (plus several presentations) you have three options to implement virtual networking in private clouds:

This is a guest blog post by Albert Siersema, senior network and cloud engineer at Mediacaster.nl. He’s always busy broadening his horizons and helping his customers in (re)designing and automating their infrastructure deployment and management.

This is the second post in a series focused primarily on brownfield automation principles using 802.1x deployments as an example (you might want to read part 1 first).

Before diving into the specifics of the next 802.1x automation phase, let’s take a step back and think about why we’re going through this effort. Automation is a wonderful tool, but it’s not a goal… and neither is 802.1x a goal - it’s just another tool that can help us realize business benefits like: