CompTIA A_ Certification All-In-One Exam Guide, Seventh Edition - Michael Meyers [435]
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NOTE As with all things computing, don’t forget to do the standard PC troubleshooting thing and reboot the computer before you do any configuration or hardware changes!
Software Troubleshooting
Because you’ve already checked to confirm that your hardware is using the correct drivers, what kind of software-related problems are left to check? Two things come immediately to mind: the wireless adapter configuration utility and the WAP’s firmware version.
As I mentioned earlier, some wireless devices won’t work correctly unless you install the vendor-provided drivers and configuration utility before plugging in the device. This is particularly true of wireless USB devices. If you didn’t do this, go into Device Manager and uninstall the device; then start again from scratch.
Some WAP manufacturers (I won’t name names here, but they’re popular) are notorious for shipping devices without the latest firmware installed. This problem often manifests as a device that enables clients to connect, but only at such slow speeds that the devices experience frequent timeout errors. The fix for this is to update the access point’s firmware. Go to the manufacturer’s Web site and follow the support links until you find the latest version. You’ll need your device’s exact model and serial number—this is important, because installing the wrong firmware version on your device is a guaranteed way of rendering it unusable!
Again, follow the manufacturer’s instructions for updating the firmware to the letter. Typically, you need to download a small executable updating program along with a data file containing the firmware software. The process takes only minutes, and you’ll be amazed at the results.
Connectivity Troubleshooting
Properly configured wireless clients should automatically and quickly connect to the desired SSID. If this isn’t taking place, it’s time for some troubleshooting. Most wireless connectivity problems come down to either an incorrect configuration (such as an incorrect password) or low signal strength. Without a strong signal, even a properly configured wireless client isn’t going to work. Wireless clients use a multi-bar graph (usually five bars) to give an idea of signal strength: zero bars indicates no signal and five bars indicates maximum signal.
Whether configuration or signal strength, the process to diagnose and repair uses the same methods you use for a wired network. First, check the wireless NIC’s link light to see whether it’s passing data packets to and from the network. Second, check the wireless NIC’s configuration utility. Typically the utility has an icon in your system tray that shows the strength of your wireless signal. Figure 24-27 shows Windows XP Professional’s built-in wireless configuration utility—called Wireless Zero Configuration (or just Zeroconf)—displaying the link state and signal strength.
Figure 24-27 Windows XP Professional’s wireless configuration utility
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NOTE If you’re lucky enough to have a laptop with an internally installed NIC (instead of a PC Card), your device may not have a link light.
The link state defines the wireless NIC’s connection status to a wireless network: connected or disconnected. If your link state indicates that your computer is currently disconnected, you may have a problem with your WAP. If your signal is too weak to receive a signal, you may be out of range of your access point, or there may be a device causing interference.
You can fix these problems in a number of ways. Because Wi-Fi signals bounce off of objects, you can try small adjustments to your antennae to see if the signal improves. You can swap out the standard antenna for one or more higher-gain antennae. You