When the network goes down, the immediate reaction of most people--even of many technicians--is to assume the worst. It's the server! It's the router! It's the Internet connection! Of course, any of these may be true--but the odds are the answer is much less complicated. While it may be counterintuitive, it's usually the simplest things--not the complex, expensive things--that break. A loose network cable, an unplugged power cord, a misconfigured software setting--all are common causes of computer network problems.

What does this mean for you? Well, first--check the cables. Let me repeat that with the appropriate emphasis: Check the cables!. If you can't get to the Internet, or to your server, or to another computer on the network, then take a few minutes to make sure the network cable for your PC is securely plugged into the wall, and into your computer. Also, verify that your PC has a "link light." This is a green or amber LED (light emitting diode) located next to the computer's network jack, that indicates you are physically connected to the network. If this light is off, then either the network is down, or your cable is bad.

And cables do go bad. They get unplugged, they get kicked, they get pulled, they get caught on things and jerked in ways that can twist and break the wires inside. Often, the damage is not visible--your only clue is that you lose your network connection.

Trust me--you will be a lot happier with yourself if you discover a bad cable at the beginning of the troubleshooting process. It can be very frustrating to spend a couple of hours fighting a network problem, only to learn that you could have fixed it in five minutes by replacing your patch cable.

Network cables are not the only inexpensive network components that occasionally fail. Just as with last week's rebooting issue, there is a larger principle at work here. Expensive equipment is more reliable. Customers generally understand if their $10 patch cable has to be replaced--but they are much more skeptical if their $1400 router goes out. Manufacturers know that customers expect expensive equipment to work--all the time. They warranty their equipment for just that reason. The last thing they want to do is irritate their customers, or cut into their own profits by servicing a warranty. So expensive equipment is generally thoroughly tested before it goes to market. Really expensive equipment is built with a certain amount of redundancy, so it can keep working, even if something does break.

The cheapest equipment, on the other hand, is considered expendable. It is more cost effective for the manufacturer of a patch cable, an adapter, or a power strip to replace it if it goes out, than to spend a lot of time and money producing versions of these items that never fail. Consequently, it is a better use of your time to check these "expendable" products first.

I recommend that you keep spare network cables of various lengths around the office. Several useful lengths include 7', 10' and 25'. Expanding on this, I recommend keeping spares of any item that costs less than $25. In addition to network cables, this includes mice, keyboards, power strips, power cords, telephone cords, and even USB hubs. This will give you the ability to quickly replace any inexpensive item that has failed, if the failure is keeping you from working.

The principal of "the simplest things break first" also extends to software. Any software configuration setting can be considered "simple," when compared to the interior workings of your server or router hardware. Because software settings are user configurable, they occasionally get changed--even when users don't realize they are changing them.

It's a good practice to keep records of the configuration settings for all your crucial software--including your email server, contact management database, accounting program, and any other application you need to do your daily work. This is something you can have your network support technician prepare in advance, so you have it handy if you are ever in the middle of a crisis, and the technician is unavailable.

The purpose of documenting the configuration is so you can review the settings if something goes wrong. An incorrect setting is easy to fix, if you recognize the problem. A record of what the settings ought to be can get you working again--when you would otherwise be down, waiting for help to arrive.

You can save yourself a lot of time and trouble by recognizing that the simple things in your network are the most likely to fail, and preparing for this possibility in advance.

Next Week: It's Probably Someone's Fault