The free InSSIDer 2 from MetaGeek helps solve this thorny problem. It searches out every wireless network in an area, shows the signal strength of each, and shows the channels that each one uses. That way, you can determine whether a nearby network might be generating interference, and change your channel.
You can also walk around your office or home with InSSIDer on a laptop, and see the signal strength in all locations, to find dead spots. Then you can solve the problem either by moving your router or by moving the PC from the poorly served location.
Xirrus Wi-Fi Inspector
A similar tool for troubleshooting wireless networks, Xirrus Wi-Fi Inspector (also free) offers even more information than InSSIDer does about each wireless network it finds. You can get information about your wireless network to make sure it's properly configured--for example, pinging your configured DNS server and gateway to confirm that they're active and working properly. A network speed tester lets you test the speed of your wireless network, too. The vendor's site for this software doesn't list it as working with Windows 7, but I ran it on Windows 7 without any problems.
Manage MAC Addresses
Every device on your network has a MAC (Media Access Control) address that uniquely identifies it. Network administrators often must find MAC addresses--for a various purposes--and this important task is no fun at all. The next two downloads may not make the work enjoyable pleasure, but they'll help you wrap up MAC address problems more quickly so you can move on to other things.
Technitium MAC Address Changer
Have intruders slipped into your network, or are your security tools working well? Technitium MAC Address Changer can help you find out. Let's say that you use MAC address filtering to ban all devices from your network except those that use specific MAC addresses. You can use Technitium MAC Address Changer to give any PC a new MAC address not normally allowed in your network, and then see whether you can evade detection by your established network security and sneak onto the network while using the new MAC address. If you can't find a way to slip in, your network is all set. If you can, that should serve as a strong signal to you that it's time to update your security.
Find MAC Address
Another great MAC address tool, LizardSystems' Find MAC Address (free for noncommercial use, $30 for business use) scans every device on your network and then reports on their MAC addresses. It even finds mobile devices such as tablets. Use the tool first to create an inventory of MAC addresses for devices that you know should be on the network; then use Find MAC Address regularly to determine whether any unauthorized devices are using the network.
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