Certain management principles cycle in and out of popularity over time. Take the acronym K.I.S.S. – Keep it Simple, Stupid. In some very real sense, the reminder that we tend to out-think ourselves when faced with everyday problems comes from a fourteenth century philosopher, William of Occam. Whether we prefer a loose translation of Occam’s Razor (The simplest explanation is invariably the best), or our modern day acronym, we do well to review the basics when complex systems break down.
A few years ago, I offered to assist a teacher at my sons’ school with a computer problem. After a few minutes of trouble shooting, I had her back up and running again. As a result, I became the “Computer Guy” for the school, and spent several evenings trying to figure out how the three buildings were networked. In a small school built 60 years ago, computers just tended to appear, and volunteers incrementally added devices and wiring to cobble together a network of sorts. Because several buildings lack ceiling access, the cabling was unsightly, and wireless had limited range inside Fallout Shelter capable buildings. Thankfully, several parents agreed to help do a complete re-wiring project. One dad owns an electrical contracting company, so he installed conduit and pulled Category Five cabling to each classroom. I provisioned single Ethernet switches in each building, while another volunteer punched down patch panels and jacks. We trashed the multiple SoHo switches and unsecured WiFi access points that littered the facilities. In a day, we had completely rewired the school.
A month or so later, one teacher told me that her computer was not working.
“What do you mean by ‘not working’?”
“I can’t do anything on it.”
“OK. I will stop by and take a look.”
The computer booted normally. I opened MS Word, typed a few sentences, and printed the document. No problem. I opened Internet Explorer, but got “Page cannot be displayed.” Of course, “Can’t do anything” equals “Can’t connect to the Internet!” Being rather familiar with TCP , IP, DNS, HTTP, and a whole mess of other Internet related abbreviations, I began to trouble shoot. To my credit, I did check the Ethernet cord, and saw the Link light indicated connectivity. I checked DNS settings, which were set to obtain automatically. Just to be sure, I statically entered the DNS. Still not able to “do anything.” I ran through the other network properties on the PC, all looked good. I decided to re-initialize the TCP stack. Still not able to “do anything.” I checked the DHCP server in the admin building, but the computer was not sending a request. I tried to set the IP manually, but I still could not “do anything.” After an hour, I pulled the cover off of the new Ethernet jack.
Too much untwisted cabling at the punch down.
The volunteer who had punched down the jacks had years of experience maintaining networks at a government facility. He knew how to use a punch-down tool, so I did not worry about training him, or checking behind him. Too late, I realized that he had not followed the Ethernet standards. Many websites discuss the importance of maintaining the twist of Ethernet Cabling. In this case, untwisting an inch of the cable made punch downs easier than punching it down with the twist maintained as closely as possible to the termination point. That blue insulation around the 8 wires should have gotten to within a quarter inch of the termination point. Something more like this:
Category 5 cabling punched down the right way.
Ethernet cable uses two pairs of twisted wires to transmit signals (Two more pairs are present, but not normally used). But untwisting Ethernet cable destroys the physics of the magnetic fields that protect the signals from each other, and from outside electronic influence. Thankfully, there were only 66 connections to check and in most cases re-punch.
Years ago, I began all training for desktop support personnel with the phrase “Layer 1 is the root of all evil.” Referencing the OSI model, the phrase reminded techs that all troubleshooting should start at the first layer – the physical connections. Is everything plugged in, and are indicator lights for connectivity good? It does no good to troubleshoot Layer 3 if Layer 1 is broken. In other words, no matter what you think the problem may be, start at the beginning. If K.I.S.S was the late 20th century’s rehash of Occam’s Razor, “Layer 1 is the root of all evil” captures Occam’s essence in the current century.