Ivan Pepelnjak

Author Archives: Ivan Pepelnjak

Leaf-and-Spine Fabrics: Implicit or Explicit Complexity?

During Shawn Zandi’s presentation describing large-scale leaf-and-spine fabrics I got into an interesting conversation with an attendee that claimed it might be simpler to replace parts of a large fabric with large chassis switches (largest boxes offered by multiple vendors support up to 576 40GE or even 100GE ports).

As always, you have to decide between implicit and explicit complexity.

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Self-Study Exercises Added to Ansible for Networking Engineers Webinar

Last week I published self-study exercises for the YAML and Jinja2 modules in the Ansible for Networking Engineers webinars, and a long list of review questions for the Using Ansible and Ansible Deeper Dive sections.

I also reformatted the webinar materials page. Hope you’ll find the new format easier to read than the old one (it’s hard to squeeze over 70 videos and links on a single page ;).

Oh, and you do know you get Ansible webinar (and over 50 other webinars) with ipSpace.net subscription, right?

Is Anyone Using Open Daylight?

A while ago I sent out an email to my SDN and network automation mailing list (join here) asking whether anyone uses Open Daylight in anything close to a production environment (because I haven’t ever seen one).

Among many responses saying “not here” I got a polite email from VP of Marketing working for a company that sells OpenDaylight-related services listing tons of customer deployments (no surprise there).

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Start Using OpenConfig with NAPALM on Software Gone Wild

OpenConfig sounds like a great idea, but unfortunately only a few vendors support it, and it doesn’t run on all their platforms, and you need the latest-and-greatest software release. Not exactly a set of conditions that would encourage widespread adoption.

Things might change with the OpenConfig data models supported in NAPALM. Imagine you could parse router configurations or show printouts into OpenConfig data structures, or use OpenConfig to configure Cisco IOS routers running a decade old software.

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Use Your Networking Knowledge to Design Automation Solution

I’m getting plenty of emails from not-so-very-young networking engineers trying to make career transitions. I got this one from a CCIE in his mid-40s:

Would you think the SDN and Data Center paths would be suitable for a long standing engineer?

Absolutely. It's just networking, although it's sometimes disguised a bit.

This article was initially sent to my Network Automation mailing list.

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Webinars in This Week

The spring craziness is still in full swing – we’ll have three webinars this week (a first) and I was so busy I didn’t even have time to write about them. Let’s fix that.

Data Center Updates on Monday is the second part of server virtualization, virtual machines and containers update to Data Center 3.0 webinar. We covered virtual machines in the last session (April 25th), this time we’ll talk about containers.

David Barroso (now at Fastly) will talk about NAPALM in Ansible on Tuesday.

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Let’s build a small network automation solution!

Do you have the feeling that you should know more about network automation, but don't know where to start? I was facing that same problem in 2015, and then started exploring Ansible (plus YAML, Jinja2, Git, Puppet…), creating small playbooks, and finally came to a point where I said "now I know that you can have a small solution solving an actual problem ready in a few weeks even if you know absolutely nothing today".

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Regional Internet Exits in Large DMVPN Deployment

One of my readers wanted to implement a large DMVPN cloud with regional Internet exit points:

We need to deploy a regional Internet exits and I’d like to centralize them.  Each location with a local Internet exit will be in a region and that location will advertise a default-route into the DMVPN domain to only those spokes in that particular region.

He wasn’t particularly happy with the idea of deploying access and core DMVPN clouds:

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Few Secrets of Successful Learning: Focus, Small Chunks, and Sleep

One of my readers sent me a few questions about the leaf-and-spine fabric architectures webinar because (in his own words)

We have some projects 100% matching these contents and it would be really useful this extra feedback, not just from consultants and manufacturer.

When I explained the details he followed up with:

Now, I expect in one or two weeks to find some days to be able to follow this webinar in a profitable way, not just between phone calls and emails.

That’s not how it works.

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