CompTIA A+® Certification All-In-One For Dummies®, 2nd Edition

2.5. Troubleshooting Issues

Any issues that affect wired networks can affect wireless networks as well. Very often, symptoms show up first on the wireless network. The bandwidth on the wireless network is substantially lower, so when a problem on your network consumes bandwidth — like a worm — it will cause connectivity and performance issues on your wireless network before users of your wired network notice the problem.

A number of outside factors, such as microwaves and cordless phones, can affect wireless networks. Because these devices operate throughout and beyond the 2.4 GHz spectrum, and because they do not advertise themselves as wireless networks, they won't show up in the results in Network Stumbler (more on that in a bit) when you are viewing the strength of wireless networks in the area. To locate these rogue signals, you need to perform a physical inspection — or, better yet, run a spectrum analysis tool. These tools used to cost thousands of dollars, but the price of quality tools has dropped to hundreds of dollars, and some tools cost even less. Managing your wireless frequencies is becoming just as important as managing your wired data networks.

To survey wireless networks in your area so that you can choose a clear channel, take a look at Network Stumbler (www.netstumbler.com). Use this tool to view detailed information about the wireless signals in your area. Figure 2-6 shows how Network Stumbler displays information about access points, including the channels ...