Bob's Blogs

Babes in Toyland

Today I thought we'd spend some time on the sorts of tools your support staff should have to make their lives easier and to make them more effective in their jobs. The signs on the sides of my truck say "Network Security" and "Troubleshooting" as the key bulleted items. The reason for this is that I've been involved in so many cases that started out looking like one and turned out to be the other. You never know until you start digging. So keep an open mind as to the possibilities.

Someone said, "The only difference between men and boys is the cost of their toys". That's not quite true, and, of course, not all of us in this business are men. I've known several female techies who loved their "techie-toys" just as much (or more) than the guys did.

So let's think (out loud) about favorite toys. I'm sure many of you will know about some that I've missed, but this should be fun anyway.

Network cable testers: These will check copper and fibers for distance, DB loss, miswirings, breakages/damage, etc. My pet Fluke one can come with several "ID" adapters for the other end, which help to identify some miswirings and help you tell one jack from another.

Adapter cable testers: These will check adapter cables that go from USB(A/B), BNC, Centronics, DB-25, DB-9, RJ-11/14/45, DB-15, AUI (also 15 pins, but larger connector/lower density) and FireWire in any combination you care to name. They will also tell you which pin on which connector is wired to which pin on the other connector.

Preface for the following two: The National Electrical Code specifies that any circuit that is under continuous load (three hours or more per day) for 15 and 20 amp branch circuits shall not exceed 80% of its rated capacity. This means that a 20 amp circuit cannot carry more than 16 amps for three hours or longer and 15 amp circuits cannot carry more than 12 amps for three hours or longer. For circuits larger than 20 amps (30+ for most purposes), the capacity of the breaker must be at least 125% of the rated full-time load. I've seen entire server rooms brought down because of daisy-chained power strips (which is a no-no from the fire marshal's point of view anyway) that finally overloaded the breaker. I've also seen data center management who, when informed that they were close to the breaking point load-wise, refused to schedule time to rearrange the loads because "we can't spare the time." I sometimes wonder if they ever got "bitten" by that.

Clamp-on ammeter: These will measure the AC amperage load of any device as long as it's clamped around ONE of the conductors. It's typically used at the breaker panel by an electrician, but I've made up some pigtails where each of the conductors has a loop sticking out and a male and female connector on the ends so that I can insert it into the power cord and measure the load of a single device or group of devices. Here's a mini-picture:


The "8" represents where the loops are sticking out of the cable, with the plug on the left side and the socket on the right side. One good way of doing this is to plug this pigtail adapter between a UPS and the wall socket. That way (unless your batteries are dead/dying) you don't interrupt a production environment. Do not leave one of these in a production environment; this is strictly a test and measurement tool. For longer term use, see the next item.
Digital load read-out power strips: These are usually bolted on to each rack of equipment and provide continuous digital readout of the current load on the power strip.

Circuit breaker locators: These handy little guys are two-part. One part plugs into a wall socket (110v only) and generates a tone on the power line (assuming that the circuit is live). You take the other end to the breaker panel and scan it over the breakers listening for the tone. If you don't find the tone, turn up the sensitivity until you do hear it. If you get the tone over several breakers, then lower the sensitivity until it's just on one breaker. If you still don't find the tone, or it shows on all breakers, find another breaker panel.

"Toner and banana": This is originally a telephone installer's tool, but it works for copper network cabling as well. Similar to the breaker locator above, it's two parts: a battery-powered tone generator that has both alligator clips and an RJ-11 plug to connect to one end of the phone line, and a battery-powered pickup that you run along the line of jacks and cable until you hear the tone. Saves a LOT of time.

Mini-Mag-Lite: 'Nuff said.

Quickie labeling machines: You know the ones. They range from 1/4" to 1" tape width with a variety of tape and print colors. Some also have USB ports so that you can drive the printing from your PC.

Tweezers: For straightening out bent pins in connectors. If you're anywhere near my age, you'll also need a….

Stand-up magnifying glass: I found a neat one that folds as a square and unfolds to stand up on its own. I've seen them in Fry's Electronics, Radio Shack, various mail-order magazines.

Universal RJ crimping tool: I've seen (no joke) the price range for these from less than $20 (Radio Shack) to over $400. Decent ones range from roughly $40 to $250. Do not buy the Radio Shack ones, as they do not enforce the proper crimping pressure on the pins. I also always use my cable tester on all crimps made at the time to eliminate the possibility that I've just introduced a problem into the environment.

Cable ties and adhesive pads: You know what they are. Question is: Do you carry some with you? You can also get cable ties with little label areas to identify a cable with your quickie label machine.

Roll of "hook and loop" ribbon: Used like cable ties, but you can undo and redo them later.

Staple gun for 8 mm round cable: Helps make visible wiring neater.

Screwdrivers: You should have at least #0, #1 and #2 Phillips and 3/16" and 1/4" or better flat blade ones. I prefer Klein because of the better quality. (They are usually sold at Electrical Wholesale houses, but I've also seen them at Home Depot.)

Pliers, wrenches, wire cutters, torx drivers, punch tools (more for telephone work)

Spare straight-through and crossover cables: Cat 5e or Cat 6 (or whatever is next).

Serial console cables: Most people are familiar with the Cisco light blue ones. But there are many brands of equipment that don't meet that standard -- including Cisco equipment from acquisitions (Arrowpoint comes to mind). I've set up my own standard based on the old US Robotics serial cable -- simply because I worked at 3Com at the time and the USR setup used all possible pins within an RJ-45, whereas the native 3Com ones did not. By setting it up this way, I've got a bunch of different style connectors (DB-9M, DB-9F, DB-25M, DB25F, RJ-45) that can be plugged in almost any serial port and to your PC (desktop or laptop) and gain instant connectivity to the console port.

10/100 Mb Hub: Not a switch, a hub. For use in sniffing traffic at odd places where you don't have access to a SPAN port. Netgear still sells these as a 4-port or 8-port unit for roughly $20-30.

USB-powered floppy diskette drive: Fewer systems these days are made with a floppy drive installed. These can still help you out of a jam. You can also still use WinZip to make a multi-volume floppy-diskette-based zip file that will span as many of these as you want.

USB external hard drive: For making copies (Ghost and such) for configurations, documents and forensic images (requires special boot CD).

Wrist grounding strap: If you're working on electronic equipment and you've got to take out parts, ground yourself to the chassis.

Generic multi-voltage power supply: Test replacement for equipment that uses those "calculator-type" power supplies. They typically have a switch on top to control the output voltage and polarity, and then a bunch of different style connectors for many devices. Just note that if you measure the output voltage not under load, it will be higher than you expect. Don't worry.

Small vacuum: Heat buildup is the enemy of all electronics. Computers, switches, routers, television sets, stereos -- doesn't matter. The buildup of dust acts as an insulating blanket that will accelerate the aging of your equipment, and in some cases cause strange failures that are difficult to diagnose. In my shop, I actually use filtered, dehumidified compressed air, and I've got a tank that I can take with me. The problem with that is if dust is a serious problem, you can't be blowing it all over, so the vacuum approach will still help -- and be neater. I just found a 1-gallon shop vacuum at a local Ace hardware store for about $40.

High-quality surge and artifact power filter: Most people think of surge protectors as keeping lightening strikes from burning up their PC. But electrical artifacts can come in the ranges of seconds, 10ths and hundredths of seconds, milliseconds, microseconds and nanoseconds. Each of those different duration artifacts can have different effects on your equipment depending on the length, spacing, repetition and frequency of the artifact, and the quality of the power supply on the equipment. The best ones are made by APC and Tripp-Lite: It's amazing how many people (and networks) suffer problems because of dirty electrical power. Since this is part of your toolkit, it's just to plug the system under suspicion into to see if cleaning up the power solves the problem. I've been called in for a few cases where the customer was sure that someone was deliberately crashing their networks, and the culprit was dirty electrical power. The solution is not one of these power strips, it's a UPS. The power strip simply helps you identify when dirty electrical power is the problem.

Just be sure to buy the very best quality tools you can afford.


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