Wireless networks should always be secured with the highest modes of encryption. I always suggest to family and friends to use WPA or WPA2 over WEP as it’s an overall higher standard. Personally, I have always used WPA2 as well as MAC ID filtering with my router; this not only has the secure encryption but also prevents any device from connecting to my network until I manually enter in their MAC address to the whitelist. Of course, setting all of this up can be overwhelming to someone who isn’t familiar with routers and overall networking, but your router manual and a quick google search should get you off down the right path.
While there are several methods to protect your wireless connection nothing is guaranteed to be 100% hack proof. So this brings up the question, how can I find out if someone else is using my internet connection?! We have recently found Wireless Network Scanner to be a great application for scanning your network and determining all of the devices connected to it.
This portable tool will grab a bunch of useful information from each device that is connected to your network in order to help identify your intruders. You are able to see the IP address, Device name, MAC address, and other network card information.
When you initially launch the application it will automatically begin searching your network, and if at anytime you need to re-scan your network just hit the green arrow button under the menu bar.
Need to print this information or save it? No worries simply export it to a convenient format (supports HTML, XML, CSV and TXT).
Wireless Network Watcher is intended for wireless networks, however, according to its developer it can also be used to scan Local Area Networks as well.
It works on Windows XP/Vista/7/Server 2003/Server 2008, and is currently free to use, download it here.