SD-WAN Reality Gap

Here’s some feedback I got from a subscriber who got pulled into an SD-WAN project:

I realized (thanks to you) that it’s really important to understand the basics of how things work. It helped me for example at my work when my boss came with the idea “we’ll start selling SD-WAN and this is the customer wish list”. Looked like business-as-usual until I realized I’ve never seen so big a difference between reality, customer wishes and what was promised to customer by sales guys I never met. And the networking engineers are supposed to save the day afterwards…

How did your first SD-WAN deployment go? Please write a comment!

Network Automation Is More than Just Ansible

One of the attendees of my Building Network Automation Solutions online course sent me this suggestion:

Stick to JUST Ansible - no GitHub, Vagrant, Docker or even Python - all of which come with their own significant learning curves.

While I understand how overwhelming the full-blown network automation landscape is to someone who never touched programming, you have to make a hard choice when you decide to start the learning process: do you want to master a single tool, or understand a whole new technology area and be able to select the best tool for the job on as-needed basis.

Large Layer-2 Domains Strike Again…

I started January 2018 blogging with a major service provider failure. Why should 2019 be any different? Here’s what Century Link claimed was causing two-day outage (more comments here).

Supposedly it was a problem with the management network used by their optical gear, but it looks a lot like a layer-2 network spanning 15 data centers and no control-plane policing on the managed devices… proving yet again that large-scale layer-2 networks are a really bad idea.

That’s It for 2018 ;)

It’s been a long year – over 230 blog posts, 30 live webinar sessions, three online courses, half-dozen workshops, tons of presentations… it’s time Irena and myself disconnect, and so should you.

Wish you a quiet and merry Christmas with your loved ones and all the best in 2019! We’ll be back in early January.

Zero-Touch Provisioning with Patrick Ogenstad (Part 2)

Last week we published the first half of interview with Patrick Ogenstad, guest speaker in Spring 2019 Building Network Automation Solutions online course (register here). Here’s the second half.

ZTP is about provisioning. Can this include configuration as well?

You could argue that provisioning is a form of configuration and in that sense, provisioning can certainly include configuration. If your ZTP solution is good at configuration management is another question.

Zen of Routing Protocols

Inspired by The Zen of Python, Dinesh Dutt wrote The Zen of Routing Protocols:

Beautiful is better than ugly.

Simple is better than complex.

Complex is better than complicated.

So just because you can, don't.

Automation, Big Data and AI

The final topic David Gee and Christoph Jaggi mentioned in their interview was big data and AI (see also: automated workflows, hygiene of network automation and network automation security):

Two other concurrent buzzwords are big data and artificial intelligence. Can they be helpful for automation?

Big Data can provide a rich pool of event-sourcing information and, as infrastructures get more complex, it’s essential that automation triggers are as accurate as possible.

Webinars in 2018

2018 was our busiest year ever… we created or updated 19 webinars, for a total of 32 live webinar sessions.

We wrapped up the 2018 webinars with Storage December featuring Hyper-Converged Infrastructure with Howard Marks and NVMe-over-Fabrics with J Metz (I never thought I would enjoy storage technology discussions, but Howard and J were brilliant)… and this is what we’ve been doing the rest of the year:

Zero-Touch Provisioning with Patrick Ogenstad

Zero-touch provisioning is always one of the big topics in the Building Network Automation Solutions online course, so we decided to invite Patrick Ogenstad (the author of excellent ZTP tutorial) to be a guest speaker in Spring 2019 course (register here).

In the meantime, enjoy his interview with Christoph Jaggi.

Using Math in Networking on Software Gone Wild

We love to claim that we’re engineers and yet sometimes we have no clue how technology we use really works and what its limitations are… quite often because understanding those limitations would involve diving pretty deep into math (graphs, queuing and system reliability quickly come to mind).

Can I Replace a Commercial Load Balancer with HAProxy?

A networking engineer attending the Building Next-Generation Data Centers online course sent me this question:

My client will migrate their data center, so they’re not interested in upgrading existing $vendor load balancers. Would HAProxy be a good alternative?

As you might be facing a similar challenge, here’s what I told him:

Building Your Own Virtual Lab

Last week we published Matt Oswalt’s thoughts on using virtual labs in training and testing. In the second part of his interview with Christoph Jaggi he talked about building a virtual lab.

Matt will cover the same topic in way more details in his guest speaker presentation in Spring 2019 Building Network Automation Solutions online course. Register here.

Segment Routing Anyone?

One of my readers listened to a podcast where a $vendor described how they found another use case for source routing IPv6 segment routing (SR): 5G networks… and wondered whether SR made a comeback or is about to.

To figure out what segment routing is, watch the webinar we did with Jeff Tantsura a while ago.

I don’t know nearly enough about mobile networks to have an opinion, however…

Using Virtual Labs When Developing Network Automation Solutions

One of the fundamentals I always emphasize in introductory parts of my network automation workshops and online courses is the fact that we’re about to develop software that will control the most-mission-critical part of IT infrastructure, and should therefore use software development methodologies like version control, testing…

However, there’s a “small” glitch. While it’s perfectly possible to test most software in some virtual environment you can spin up on-the-fly using Vagrant, Docker, Jenkins, Travis, or some other CI/CD tool, testing a network automation solution requires access to network devices.

Video: What Problem Are We Solving with SDDC?

Remember the Software-Defined Data Centers hype? While I covered SDDC concepts and technologies for years in my webinars and workshops, I never created an introductory webinar on the topic.

That omission has been fixed in late August – SDDC 101 webinar is available as part of free subscription, and as always I started with the seemingly simple question: What problem are we trying to solve?

Odd Number of Spines in Leaf-and-Spine Fabrics

In the market overview section of the introductory part of data center fabric architectures webinar I made a recommendation to use larger number of fixed-configuration spine switches instead of two chassis-based spines when building a medium-sized leaf-and-spine fabric, and explained the reasoning behind it (increased availability, reduced impact of spine failure).

One of the attendees wondered about the “right” number of spine switches – does it has to be four, or could you have three or five spines. In his words:

Bifurcation of Knowledge

My friend Andrea Dainese (of the Route Reflector Labs fame) sent me this observation:

Because of lack of fundamental skills, I see two groups forming: junior guys with low salary (the bigger group), and a few experts (hopefully with higher salary). The middle group is disappearing. Intermediate-level engineers are either moving to the entry level (because the complexity is increasing and they are not keeping up with it) or to the upper level.

I call this phenomenon bifurcation of knowledge (I’m positive it has a formal name – would appreciate a comment with a set of pointers), and it’s a direct result of commoditization and the changing shape of the learning curve.

David Gee on Security of Network Automation

One of the points David Gee, a guest speaker in Spring 2019 Building Networking Automation Solutions online course, and Christoph Jaggi touched on in their interview was the security of network automation solutions (see also: automated workflows and hygiene of network automation).

What are the security risks for automation?

Security is an approach, not an afterthought.

Worth Reading: Back to Basics

I’m not the only one ranting about the need to get a firm grasp on fundamentals before doing the sexy stuff. Found an old blog post by Joel Spolsky (of the Law of Leaky Abstractions fame) on the exact same topic from programming perspective.

If you ever had to deal with a programming language, it’s definitely worth reading… but some of the details might make your head explode. You’ve been warned ;)

Interview: Active-Active Data Centers with VXLAN and EVPN

Christoph Jaggi asked me a few questions about using VXLAN with EVPN to build data center fabrics and data center interconnects (including active/active data centers). The German version was published on Inside-IT, here’s the English version.

He started with an obvious one:

What is an active-active data center and why would I want to use an active-active data center?

Numerous organizations have multiple data centers for load sharing or disaster recovery purposes. They could use one of their data centers and have the other(s) as warm or cold standby (active/backup setup) or use all data centers at the same time (active/active).