My commentary about solving wireless networking problems (May 11, 2006, InstantDoc ID 50339) generated quite a few reader questions, primarily about security and using wireless bridges. Based on those reader questions, my commentary details how to secure your wireless network and explains more about wireless bridges.
5 Things You Can Do to Secure Your Wireless Network
1. Put a password on your wireless router/access point (AP). It’s amazing how often I come across wireless networks that retain the default router name and password. Every other security option is meaningless if the router isn't secured. You might also consider disabling remote administration unless you have a reason to administer the router from a location other than the local network.
2. Turn off broadcast of the Service Set Identifier (SSID). By default, your router will broadcast your wireless network's SSID. The SSID will then be visible to anyone with a computer and a wireless networking card. However, before you turn off the SSID, you need to know the name of the wireless network should you want to access it, as turning off the SSID means you won't automatically be able to get that name.
3. Consider disabling DHCP. If only a few systems access the wireless network, you might want to turn off DHCP and give the clients static IP addresses, which have to be assigned manually and must match the IP address range supported by the router. Otherwise, if you use DHCP, any DHCP client that finds the network will be assigned an address. Disabling DHCP is simple and prevents unauthorized users from getting a network-supplied IP.
4. Use MAC-address filtering. MAC addresses are specific to individual network devices. When you type “ipconfig /all” at a command prompt in Windows, one of the items returned is titled Physical Address and consists of six pairs of numbers. These numbers are the MAC address of the adapter, which is stored in the network adapter ROM. You can lock down your wireless network by configuring your router to accept only connections from a specific list of PCs by their MAC address. Unfortunately, this is a time-consuming task if you need to add hundreds of PCs to the list. Once the list is created, however, adding individual PCs to it is simple.
5. Enable encryption. Although Windows defaults to the 802.11 Wired Equivalent Privacy (WEP) standard when encryption is enabled, consider upgrading to Wi-Fi Protected Access (WPA). WPA provides a stronger security model than WEP, and you can download WPA support to Windows XP (if you don't already have Service Pack 2--SP2--which already has it). My tip (see below) references a URL for downloading the WPA support patch as well as other helpful URLS related to WPA. Regardless of which encryption method you choose, you should use one, even if WPA isn’t supported on all your clients.
Many brands and models of wireless routers and APs support these five tasks and when combined with them will provide solid wireless network security.
Understanding Wireless Bridges
You can find a broad range of wireless bridges, from products capable of connecting networks that are 50 miles apart to products that enable building-to-building connections to simple bridges that allow wireless networks to connect back to wired components. I mentioned the last type in the May 11, 2006, "Windows Client UPDATE." These simple bridges are inexpensive units (typically from $100 to $400 depending on capabilities) that let you connect a wired Ethernet component to your existing wireless network.
In my home, I use a simple wireless bridge to connect my Turtle Beach AudioTron digital music player, which is attached to the stereo system in the family room, to my wireless network for access to the music server, which is on a wired network in my home office. The bridge also provides general Internet access to the player so that I can listen to Internet radio stations. This same type of bridge could connect any wired Ethernet networking device to a wireless network.
The more expensive wireless bridges offer greater management capabilities and are often referred to as workgroup bridges. They are generally used to connect wireless workgroups to larger wired networks.
Tip--Download Wi-Fi Protected Access Support
Wi-Fi Protected Access (WPA) support is included in the Windows XP SP2 release. For complete details on using this capability check out http://support.microsoft.com/?kbid=815485
If you aren’t using SP2 with XP, you can download the WPA support patch at http://www.microsoft.com/downloads/details.aspx?displaylang=en&familyid=009d8425-ce2b-47a4-abec-274845dc9e91
Windows 2000 users can download a free version of McAfee Wireless Security that supports WPA at http://www.wirelesssecuritycorp.com/wsc/public/WPAAssistant.do Microsoft doesn't offer WPA support for OSs earlier than XP.