Ivan Pepelnjak

Author Archives: Ivan Pepelnjak

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.

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VNFs and Containers: Heptagonal Pegs and Triangle Holes

One of my readers sent me this question:

It would be nice to have a blog post or a webinar describing how to implement container networking in case when: (A) application does not tolerate NAT (telco, e.g. due to SCTP), (B) no DNS / FQDN, is used to find the peer element and (C) bandwidth requirements may be tough.

The only thing I could point him to is the Advanced Docker Networking part of Docker Networking Fundamentals webinar (available with free subscription) where macvlan and ipvlan are described.

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Using MPLS+EVPN in Data Center Fabrics

Here’s a question I got from someone attending the Building Next-Generation Data Center online course:

Cisco NCS5000 is positioned as a building block for a data center MPLS fabric – a leaf-and-spine fabric with MPLS and EVPN control plane. This raised a question regarding MPLS vs VXLAN: why would one choose to build an MPLS-based fabric instead of a VXLAN-based one assuming hardware costs are similar?

There’s a fundamental difference between MPLS- and VXLAN-based transport: the amount of coupling between edge and core devices.

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Upcoming Webinars and Events: November 2018

The last two months of 2018 will be jam-packed with webinars and on-site events:

December will be a storage, EVPN and SDN month:

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It’s All About Business…

A few years ago I got cornered by an enthusiastic academic praising the beauties of his cryptography-based system that would (after replacing the whole Internet) solve all the supposed woes we’re facing with BGP today.

His ideas were technically sound, but probably won’t ever see widespread adoption – it doesn’t matter if you have great ideas if there’s not enough motivation to implementing them (The Myths of Innovation is a mandatory reading if you’re interested in these topics).

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netdev 0x12 Update on Software Gone Wild

In recent years Linux networking started evolving at an amazing pace. You can hear about all the cool new stuff at netdev conference… or listen to Episode 94 of Software Gone Wild to get a CliffsNotes version.

Roopa Prabhu, Jamal Hadi Salim, and Tom Herbert joined Nick Buraglio and myself and we couldn’t help diverging into the beauties of tc, and the intricacies of low-latency forwarding before coming back on track and started discussing cool stuff like:

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What’s the Big Deal with Validation?

This blog post was initially sent to subscribers of my mailing list. Subscribe here.

In his Intent-Based Networking Taxonomy blog post Saša Ratković mentioned real-time change validation as one of the requirements for a true intent-based networking product.

Old-time networkers would instinctively say “sure, we need that” while most everyone else might be totally flabbergasted. After all, when you create a VM, the VM is there (or you’d get an error message), and when you write to a file and sync the file system the data is stored, right?

As is often the case, networking is different.

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VMware NSX: The Good, the Bad and the Ugly

After four live sessions we finished the VMware NSX Technical Deep Dive webinar yesterday. Still have to edit the materials, but right now the whole thing is already over 6 hours long, and there are two more guest speaker sessions to come.

Anyways, in the previous sessions we covered all the good parts of NSX and a few of the bad ones. Everything that was left for yesterday were the ugly parts.

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Figuring Out AWS Networking

One of my friends reviewing the material of my AWS Networking webinar sent me this remark:

I'm always interested in hearing more about how AWS network works under the hood – it’s difficult to gain that knowledge.

As always, it’s almost impossible to find out the behind-the-scenes details, and whatever Amazon is telling you at their re:Invent conference should be taken with a truckload of salt… but it’s relatively easy to figure out a lot of things just by observing them and performing controlled experiments.

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Automation Win: Configure Cisco ACI with an Ansible Playbook

This blog post was initially sent to subscribers of my mailing list. Subscribe here.

Following on his previous work with Cisco ACI Dirk Feldhaus decided to create an Ansible playbook that would create and configure a new tenant and provision a vSRX firewall for the tenant when working on the Create Network Services hands-on exercise in the Building Network Automation Solutions online course.

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New: Expert ipSpace.net Subscription

Earlier this month I got this email from someone who had attended one of my online courses before and wanted to watch another one of them:

Is it possible for you to bundle a 1 year subscription at no extra cost if I purchase the Building Next-Generation Data Center course?

We were planning to do something along these lines for a long time, and his email was just what I needed to start a weekend-long hackathon.

End result: Expert ipSpace.net Subscription. It includes:

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