I run my home wireless network from a D-Link DI-624 wireless router, and access is restricted by passwords and MAC address filtering. I'm the only one who knows the passwords. However, I keep seeing new addresses appearing on the list of allowed MAC addresses. I have removed them from the list, but they come back. I assume that this means someone is bypassing my security, and that they must be fairly serious if they are getting through all those security measures. Ian Sudbery
Most internet, Wi-Fi and Bluetooth devices have a Media Access Control (MAC) address, which starts with something that identifies the manufacturer. You can paste these characters into the Vendor/Ethernet MAC Address Lookup and Search site at coffer.com/mac_find/ and see if you recognise what comes up. One might be your router, or whatever. Your PCs may have two: one for built-in Ethernet and one for a wireless card.
However, these universally administered addresses can be overridden by locally administered addresses -- ones you have assigned. MAC filtering isn't secure because if you can change them, so can the hacker.
If identifying the devices doesn't solve the problem, then you may have to upgrade from WEP (Wired Equivalent Privacy), which isn't secure, to WPA2 (Wi-Fi Protected Access), which was added to the standard this year.
You will probably need to download a software update for your operating system -- perhaps the one for Windows XP SP2 -- plus new drivers for wireless cards. Many routers will also need firmware updates. There's one for the DI-624, but make sure you download it from your local D-Link country site and install it via a cable connection.
