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Author: John Harrington

Solarwinds Geek Speak

Solarwinds Geek Speak

I’m sharing some articles I wrote on the Solarwinds Geek Speak blog.  I recommend you start with the 80/20 rule below post below before reading through the rest. The 80-20 Rule of Analysis and Optimisation Start with Continuous Improvement, then do DevOps The pain of network variation – part 1 The pain of network variation – part 2 A disclaimer: Solarwinds didn’t ask me to promote these posts –  I’m sharing them because they’re posts I would have otherwise published…

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The Feynman Principle

The Feynman Principle

Interviews will often start with softball questions like… So why are you interested in working for our company? This question gives the candidate an easy way to warm-up and could give the interviewer some insights into the candidate. I’ve asked this question many time and sometimes heard a reply like.. I really want to learn about large scale networks. My current network is too small and is limiting my progress.

Strain relief

Strain relief

I’ve got a problem with sagging cables, and I’ve got a simple solution. Examine the side-by-side images below which show the same fiber connection between a switch and a firewall. The image on the left shows a sagging cable which crosses in front of the switch in the rack unit just below it. As you may know, this cabling install is a violation of the 167th rule of networking: Thou shalt contain your cables to your own rack unit and shalt not, under any circumstances,…

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Effectiveness – Network Truths, Principles and Fallacies

Effectiveness – Network Truths, Principles and Fallacies

I gave a 13-minute talk to the Irish Network Operators Group (INOG) recently. In this 13-minute video I argue that you can become more effective, and happier, by standing back and reflecting on how you work, leveraging existing truths, fallacies and principles. I introduce The twelve networking truths and the 8 Fallacies of Distributed Computing. I then describe a handful of my own learnings and fancy terms like Chestertons Fence and the Gordian Knot. Check out the video folks, I’d love your feedback.

Clear Pricing for Network Services

Clear Pricing for Network Services

I had to buy some switches recently and needed to gather a second quote from another vendor. I went to the Dell website and was pleasantly surprised to quickly find a clear price and a buy-now button for each device on their website. Normally you’d need an account of the vendors portal to get this information, so it is refreshing to have straightforward access to clear hardware pricing. However it was the list of professional services options shown in the attached image that caught my eye.

Writing elsewhere on the net

Writing elsewhere on the net

Hi Folks, I write for a few other publications, so I’ve made this handy page to link to external articles. I’ll update this page as new articles are released. Human Infrastructure Magazine Issue 23 – How To Unblock Your Project Issue 27 – Email Stinks For Process Documentation Network Computing Demystifying The 10x Network Engineer The Broken Window Theory of Network Configuration Packet Pushers All my posts on the PacketPushers Blog Enjoy.

Include the why

Include the why

I recently stumbled upon an interesting speech from 1984 by Charlie Munger of Bershire Hathaway fame. Charlie is Warren Buffet’s right-hand-man, and a straight talking genius in his own right. It’s a fairly long speech and Charlie has a few very interesting things to say, but one particular section on ‘explaining the why’ really struck home. Here’s a brief quote: ….if you always tell people why, they’ll understand it better, they’ll consider it more important, and they’ll be more likely…

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Getting started with Network Packet Generators

Getting started with Network Packet Generators

A friend of mine has just ordered a shiny new packet generator for his network lab. I’ve spent some time working as a QA engineer in a network lab and wanted to share some advice. You can purchase stateful and stateless packet generators from major vendors like Spirent, IXIA or Agilent. If you just need to test throughput, latency or loss, a stateless packet generator will do the trick. The test hardware will use an ASIC to produce line-rate 10G traffic…

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5 ways to fail – WAN link acceptance

5 ways to fail – WAN link acceptance

I’ve had an interesting few months doing WAN circuit turn-ups for a new Data Centre. I dealt with three major carriers, and each experience was worse than the next. I’m not sure why I held such high expectations but I was surprised by their hopeless inefficiency in delivering what should have been a standard product. In this post I’ll examine the problems I saw and their root causes. In all three situations, 1Gbps Layer-2 ethernet circuit was ordered with a copper ethernet handoff…

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