All posts tagged sd-wan

“Progress might have been alright once, but it has gone on too long.”
–  Ogden Nash

The book The Innovator’s Dilemma appears on the desk of a lot of Silicon Valley executives.  Its author, Clayton Christiensen, is famous for having coined the term “disruptive innovation.”  The term has always bothered me, and I keep waiting for the word “disruption” to die a quiet death.  I have the disadvantage of having studied Latin quite a bit.  The word “disrupt” comes from the Latin verb rumperewhich means to “break up”, “tear”, “rend”, “break into pieces.”  The word, as does our English derivative, connotes something quite bad.  If you think “disruption” is good, what would you think if I disrupted a presentation you were giving?  What if I disrupted the electrical system of your heart?

Side note:  I’m fascinated with the tendency of modern English to use “bad” words to connote something good.  In the 1980’s the word “bad” actually came to mean its opposite.  “Wow, that dude is really bad!” meant he was good.  Cool people use the word “sick” in this way.  “That’s a sick chopper” does not mean the motorcycle is broken.

The point, then, of disruption is to break up something that already exists, and this is what lies beneath the b-school usage of it.  If you innovate, in a disruptive way, then you are destroying something that came before you–an industry, a way of working, a technology.  We instantly assume this is a good thing, but what if it’s not?  Beneath any industry, way of working, or technology are people, and disruption is disruption of them, personally.

The word “innovate” also has a Latin root.  It comes from the word novus, which means “new”.  In industry in general, but particularly the tech industry, we positively worship the “new”.  We are constantly told we have to always be innovating.  The second one technology is invented and gets established, we need to replace it.  Frame Relay gave way to MPLS, MPLS is giving way to SD-WAN, and now we’re told SD-WAN has to give way…  The life of a technology professional, trying to understand all of this, is like a man trying to walk on quicksand.  How do you progress when you cannot get a firm footing?

We seem to have forgotten that a journey is worthless unless you set out on it with an end in mind.  One cannot simply worship the “new” because it is new–this is self-referential pointlessness.  There has to be a goal, or an end–a purpose, beyond simply just cooking up new things every couple years.

Most tech people and b-school people have little philosophical education outside of, perhaps (and unfortunately) Atlas Shrugged.  Thus, some of them, realizing the pointlessness of endless innovation cycles, have cooked up ludicrous ideas about the purpose of it all.  Now we have transhumanists telling us we’ll merge our brains with computers and evolve into some sort of new God-species, without apparently realizing how ridiculous they sound.  COVID-19 should disabuse us of any notion that we’re not actually human beings, constrained by human limitations.

On a practical level, the furious pace of innovation, or at least what is passed off as such, has made the careers of technology people challenging.  Lawyers and accountants can master their profession and then worry only about incremental changes.  New laws are passed every year, but fundamentally the practice of their profession remains the same.  For us, however, we seem to face radical disruption every couple of years.  Suddenly, our knowledge is out-of-date.  Technologies and techniques we understood well are yesterday’s news, and we have to re-invent ourselves yet again.

The innovation imperative is driven by several factors:  Wall Street constantly pushes public companies to “grow”, thus disparaging companies that simply figure out how to do something and do it well.  Companies are pressured into expanding to new industries, or into expanding their share of existing industries, and hence need to come up with ways to differentiate themselves.  On an individual level, many technologists are enamored of innovation, and constantly seek to invent things for personal satisfaction or for professional gain.  Wall Street seems to have forgotten the natural law of growth.  Name one thing in nature that can grow forever.  Trees, animals, stars…nothing can keep growing indefinitely.  Why should a company be any different?  Will Amazon simply take over every industry and then take over governing the planet?  Then what?

This may seem a strange article coming from a leader of a team in a tech company that is handling bleeding edge technologies.  And indeed it would seem to be a heresy for someone like me to say these things.  But I’m not calling for an end to inventing new products or technologies.  Having banged out CLI for thousands of hours, I can tell you that automating our networks is a good thing.  Overlays do make sense in that they can abstract complexity out of networks.  TrustSec/Scalable Group Tags are quite helpful, and something like this should have been in IP from the beginning.

What I am saying is that innovation needs a purpose other than just…innovation.  Executives need to stop waxing eloquent about “disrupting” this or that, or our future of fusing our brains with an AI Borg.  Wall Street needs to stop promoting growth at all costs.  And engineers need time to absorb and learn new things, so that they can be true professionals and not spend their time chasing ephemera.

Am I optimistic?  Well, it’s not in my nature, I’m afraid.  As I write this we are in the midst of the Coronavirus crisis.  I don’t know what the world will look like a year from now.  Business as usual, with COVID a forgotten memory?  Perhaps.  Great Depression due to economic shutdown?  Perhaps.  Total societal, governmental, and economic collapse, with rioting in the streets?  I hope not, but perhaps.  Whatever happens, I do hope we remember that word “novel”, as in “novel Coronavirus”, comes from the same Latin root as the word “innovation”.  New isn’t always the best.

There were quite a few big announcements at Cisco Live this year.  One of the big ones was the overhaul of the certification program.  A number of new certifications were introduced (such as the DevNet CCNA/CCNP), and the existing ones were overhauled.  I wanted to do a post about this because I was involved with the certification program for quite a while on launching these.  I’m posting this on my personal blog, so my thoughts here are, of course, personal and not official.

First, the history.  Back when I was at Juniper, I had the opportunity to write questions for the service provider written exams.  It was a great experience, and I got thorough training from the cert program on how to properly write exam questions.  I don’t really remember how I got invited to do it, but it was a good opportunity, as a certified (certifiable?) individual, to give back to the program.  When I came to Cisco, I quickly connected with the cert program here, offering my services as a question writer. I had the training from Juniper, and was an active CCIE working on programmability.  It was a perfect fit, and a nice chance to recertify without taking the test, as writing/reviewing questions gets your CCIE renewed.

As I was managing a team within the business unit that was working on Software-Defined Access and programmability, it seemed logical for me to talk to the program about including those topics on the test.  I can assure you there was a lot of internal debate about this, as the CCIE exam is notoriously complex, and the point of our Intent-Based Networking products is simplicity.  One product manager even suggested a separate CCIE track for SD-Access, an idea I rejected immediately for that very reason.

Still, as I often point out here and elsewhere, SDN technologies do not mitigate the need for network engineers.  SDN products, all SDN products, are complex precisely because they are automated.  Automation enables us to build more complex things, in general.  You wouldn’t want to configure all the components of SD-Access by hand.  Still, we need engineers who understand what the automation tools are doing, and how to work with all the components which comprise a complex solution like SD-Access.  Network engineers aren’t going to disappear.

For this reason, we wanted SD-Access, SDWAN, and also device programmability (NETCONF/YANG, for example) to be on the lab.  We want to have engineers who know and understand these technologies, and the certification program is a fantastic way to help people to learn them.  I, and some members of my team, spent several months working with the CCIE program to build a new blueprint, which became the CCIE Enterprise Infrastructure.  The storied CCIE Routing and Switching will be no more.

At the end of the day, the CCIE exam has always adapted to changed in networking.  The R/S exam no longer has ISDN or IPX on it, nor should it.  Customers are looking for more automated solutions, and the exam is keeping pace.  If you’re studying for this exam, the new blueprint may be intimidating.  That said, CCIE exams have always been intimidating.  But think about this:  if you pass this exam, your resume will have skills on it that will make you incredibly marketable.

The new CCIE-EI (we always abbreviate stuff, right?) breaks down like this:

  • 60% is classic networking, the core routing protocols we all know and love.
  • 25% is SDx:  SD-Access and SD-WAN, primarily.
  • 15% is programmability.  NETCONF/YANG, controller APIs, Ansible, etc.

How do you study for this?  Like you study for anything.  Read about it and lab it.  There is quite a bit of material out there on all these subjects, but let me make some suggestions:


You are not expected to be a programming expert for this section of the exam.  It’s not about seeing if you can write complex programs, but whether you know the basics well enough to execute some tasks via script/Ansible/etc instead of CLI.  DevNet is replete with examples of how to send NETCONF messages, or read data off a router or switch with programmable interfaces.  Download them, play with them, spend some time learning the fundamentals of Python, and relax about it.

  • Learn:  DevNet is a phenomenal resource.  Hank Preston, an evangelist for DevNet, has put out a wealth of material on programmability.  In addition, there is the book on IOS XE programmability I wrote with some colleagues.
  • Lab:  You can lab programmability stuff easily on your laptop.  Python and ncclient are free, as is Ansible.  If you have any sort of lab setup already, all you need to do is set up a Linux VM or install some tools on to your laptop.


This is, as I said before, a tough one to test on.  After all, to add a device to an SD-Access fabric, you select it and click “Add to Fabric.”  What’s there to test?  Well, since these are new products you of course need to understand the components of SD-Access/SDWAN and how they interoperate.  How does policy work?  How do fabric domains talk to non-fabric domains?  There is plenty to study here.

  • Learn:  Again, we’ve written books on SD-Access and SD-WAN.  Also, we are moving a lot of documentation into Cisco Communities.
  • Lab:  Well, this is harder.  We’re working on getting SD-Access into the hands of learning partners, so you’ll have a place to get your hands on it.  We’re also working on virtualizing SD-Access as much as possible, to make it easier for people to run in labs.  I don’t have a timeframe on the latter, but hopefully the former we can do soon.

These are huge but exciting changes. I’ve been very lucky to have landed at a job where I am at the forefront of the changes in the industry, but this new exam will give others the opportunity to move themselves in that direction as well.  Happy labbing!