Remember how earlier releases of Nexus-OS started dropping configuration commands if you were typing them too quickly (and how it was declared a feature ;)?

Mark Fergusson had a similar experience on Cisco IOS. All he wanted to do was to use Ansible to configure a VRF, an interface in the VRF, and OSPF routing process on Cisco CSR 1000v running software release 15.5(3).

Here’s what he was trying to deploy. Looks like a configuration straight out of an MPLS book, right?

The crazy pace of webinar sessions continued last week. Howard Marks continued his deep dive into Hyper-Converged Infrastructure, this time focusing on go-to-market strategies, failure resiliency with replicas and local RAID, and the eternal debate (if you happen to be working for a certain $vendor) whether it’s better to run your HCI code in a VM and not in hypervisor kernel like your competitor does. He concluded with the description of what major players (VMware VSAN, Nutanix and HPE Simplivity) do.

When I was writing the Back to Basics blog post I reread the Law of Leaky Abstractions masterpiece. You’ll love it – the first example Joel uses is TCP.

However, what really caught my eye was this bit:

The law of leaky abstractions means that whenever somebody comes up with a wizzy new code-generation tool that is supposed to make us all ever-so-efficient, you hear a lot of people saying “learn how to do it manually first, then use the wizzy tool to save time.”

You should apply the same wisdom to shiny new gizmos launched by network virtualization vendors… oh wait, you can’t, they are mostly undocumented black boxes. Good luck ;)

I know many networking engineers who went into networking because they didn’t want to write code the rest of their lives. I also know a few awesome engineers who decided to keep coding while designing networks.

Andrea Dainese (author of UNetLab – the tool you might know as EVE-NG) is one of the latter and practiced network automation for years, dealing with all sorts of crappy device configuration and monitoring mechanisms, from screen- and web scraping to broken REST APIs.

One of my subscribers sent me a question along these lines (heavily abridged):

My customer runs a colocation business and has to provide L2 connectivity between racks, sometimes even across multiple data centers. They were using Q-in-Q to deliver that in a traditional fabric and would like to replace that with multi-site EVPN fabric with ~100 ToR switches in each data center. However, Cisco doesn’t support Q-in-Q with multi-site EVPN. Any ideas?

As Lukas Krattiger explained in his part of Multi-Site Leaf-and-Spine Fabrics section of Leaf-and-Spine Fabric Architectures webinar, multi-site EVPN (VXLAN-to-VXLAN bridging) is hard. Don’t expect miracles like Q-in-Q over VNI any time soon ;)

In summer 2018 Juniper started talking about another forward-looking concept: Network Reliability Engineering. We wanted to find out whether that’s another unicorn driving DeLorean with flux capacitors or something more tangible, so we invited Matt Oswalt, the author of Network Reliability Engineer’s Manifesto to talk about it in Episode 97 of Software Gone Wild.

In the first part of his interview with Christoph Jaggi Kristian Larsson talked about the basics of CI testing. Now let’s see how you can use these concepts in network automation.

How does CI testing fit into an overall testing environment?

Traditionally, in particular in the networking industry, it's been rather common to have proof of concepts (POC) delivered by vendors for various networking technologies and then people have sat down and manually tested that the POC meets some set of requirements.

As I’m doing occasional consulting for large enterprises redesigning their data centers, I encounter a wide range of network automation readiness, from “we don’t need that” to “how could we automate as much as possible”.

Based on the pervasiveness of “we don’t need that” responses it looks like many enterprise network engineers still have to go through the five stages of automation grief.

One of the attendees of the Building Next-Generation Data Center online course solved the build small data center fabric challenge with Virtual Chassis Fabric (VCF). I pointed out that I would prefer not to use VCF as it uses centralized control plane and is thus a single failure domain.

Here are his arguments for using VCF:

Every now and then someone tells me I should write more about the basic networking concepts like I did years ago when I started blogging. I’m probably too old (and too grumpy) for that, but fortunately I’m no longer on my own.

Over the years ipSpace.net slowly grew into a small community of networking experts, and we got to a point where you’ll see regular blog posts from other community members, starting with Using BGP as High-Availability protocol written by Nicola Modena, member of ExpertExpress team.