Ivan Pepelnjak

Author Archives: Ivan Pepelnjak

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.

Read more ...

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:

Read more ...

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.

Read more ...

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).

Read more ...

OMG, VXLAN Is Still Insecure

A friend of mine told me about a “VXLAN is insecure, the sky is falling” presentation from RIPE-77 which claims that you can (under certain circumstances) inject packets into VXLAN virtual networks from the Internet.

Welcome back, Captain Obvious. Anyone looking at the VXLAN packet could immediately figure out that there’s no security in VXLAN. I pointed that out several times in my blog posts and presentations, including Cloud Computing Networking (EuroNOG, September 2011) and NSX Architecture webinar (August 2013).

Read more ...

Using VXLAN and EVPN to Build Active-Active Data Centers

Some (anti)patterns of network industry are way too predictable: every time there’s a new technology marketers start promoting it as the solution for every problem ever imagined. VXLAN was quickly touted as the solution for long-distance vMotion, and now everyone is telling you how to use VXLAN with EVPN to stretch VLANs across multiple data centers.

Does that make sense? It might… based on your requirements and features available on the devices you use to implement the VXLAN/EVPN fabric. We’ll cover the details in a day-long workshop in Zurich (Switzerland) on December 5th. There are still a few places left, register here.

David Gee on Automated Workflows

David Gee is coming back to Building Network Automation Solutions online course – in early March 2019 he’ll talk about hygiene of network automation. Christoph Jaggi did an interview with him to learn more about the details of his talk, and they quickly diverted into an interesting area: automated workflows.

Automation is about automated workflows. What kind of workflows can be automated in IT and networking?

Workflows most often fall into categorizations of build, operations and remediation.

Read more ...

Don’t Let the Automation Snowflakes Stop You

You know that time of year when snowflakes mean more than description of uniqueness of your networking infrastructure? Some people love to complain about that season and how the weather hinders them, others put on sturdy winter boots and down jackets, change tires on their car, and have tons of fun.

Network automation is no different. Sometimes you can persuade your peers that it makes sense to simplify and standardize the infrastructure to make it easier to abstract and automate (consider that an equivalent of going to a tropic island with shiny beaches and everlasting summer), other times you have to take out your winter boots and make the best out of what you got.

Read more ...
1 2 3 53