How to Enhance and Secure Your Wi-Fi Network

If your Skype or Second Life sessions start breaking up, or your iTunes stream gets clogged whenever your teenager starts playing World of Warcraft, you may be able to improve matters without having to buy a new router. Most routers sold in the last couple of years have a quality of service (QoS) feature, although you may need to update your router firmware to activate it. For example, the configuration program for Linksys routers has a QoS tab under 'Applications & Gaming' (first make sure 'WMM Support' is enabled, as in this screen shot).

Turn on Internet Access Priority for your voice and media applications. First, select each from the drop-down list.

Then, choose High, Medium, Normal, or Low priority, and click the 'Add' button. You may want to set a low priority to things like BitTorrent and other download services, and give your VoIP service a high priority, for example. Note that the Linksys utility also lets you set the priority for specific voice devices, such as VoIP phones that connect directly to your network. Not all routers can prioritize particular applications or devices, but at the very least, turn QoS or WMM on, which automatically attempts to optimize media traffic; this setting is off by default on many routers.

On the road, it's best to turn your notebook's Wi-Fi adapter completely off when you aren't using it. This prevents you from inadvertently connecting to a malicious hotspot, and it extends your laptop's battery life. Some newer notebooks have a hardware button that does this; otherwise, to turn off Wi-Fi in Windows XP, click the wireless network icon in the system tray and choose 'Disable'.

Disabling the adapter removes its icon from the system tray. To restore it in XP, open the 'Network Connections' Control Panel applet and double-click your wireless connection.

To enable or disable your Wi-Fi adapter in Vista, open the 'Network and Sharing Center' Control Panel applet and choose 'View status' under 'Connections'. If you use your adapter vendor's software--rather than the Windows Wi-Fi tools--in either XP or Vista, you may need to use that software to turn the adapter on or off.

Strangers may be lurking on your home Wi-Fi network. Don't assume that you are protected just because you have Wi-Fi encryption. Encryption--especially WEP--can be cracked. And even MAC-address filtering can be spoofed. To give interlopers the boot, download and install the free version of Network Magic. The program shows you a map of all of the computers, media servers, printers, and other devices connected to your network. Any listing that you can't identify is a potential intruder.

Unfortunately, you probably won't have the Network Magic window open all the time, but you can set it to pop up an alert whenever a new device connects to the network, so you can investigate possible intrusions as soon as they happen. To do this, choose 'Options' from the 'Tools' menu, click the 'Notifications' tab, and check 'A new device joins the network'.

Finally, click the 'Security' tab, and check 'Automatically track new devices as Intruders' so you can monitor their activity. This is especially useful if you are away from your desk when the intrusion occurs.

The Linksys Wireless-G Travel Router has one key feature that no other such device can boast: It lets you share a Wi-Fi or wired connection over your own secured Wi-Fi network. You can use the device to share a paid hotel broadband link--or even a T-Mobile Hotspot connection at Starbucks, as long as you can find a power outlet for it.

To share a Wi-Fi connection, simply turn on the router, connect to it via Wi-Fi, and open its configuration utility in your browser. Choose the hotspot that you want to connect to from the list of available networks (such as 'T-Mobile'), and click the 'Select' button. Now open a new browser window and log in to the hotspot, making any payment needed. Other computers that connect to the Linksys Travel Router will also connect to the paid hotspot, at no extra charge.

Public hotspots are a hacker's delight. The networks lack encryption precisely because they need to be open to all comers. Unless you use virtual private network (VPN) software, anyone can see all of your wireless Internet traffic, including passwords and e-mail messages. If you don't have access to VPN, the best free VPN software is Hotspot Shield from AnchorFree. Just download and install it, and your Web browser will display the screen pictured here. Click 'Run Hotspot Shield', and the app's protection will start.

To turn off Hotspot Shield when you leave the hotspot, right-click the green shield icon in the system tray and click 'Disconnect'. The shield will then turn red, signifying that VPN is no longer active. To reenable it, right-click again and choose 'Connect'.

While you're connected, choose 'Properties' from the system tray icon to see what your current IP address is. Though Hotspot Shield is free, it does put a banner ad at the top of your browser pages while you surf. But that's a small price to pay for complete hotspot security. You can even use the program on your home network, if you think intruders may be listening in.

One of the most common Wi-Fi security dangers comes from malicious networks, called "ad-hoc" Wi-Fi connections, that emanate from other computers. For example, a hacker can sit down in an airport and start broadcasting an SSID called 'T-Mobile' or 'Free Wi-Fi', which your Wi-Fi adapter may automatically connect to. Or you may inadvertently click it, thereby giving the person access to your computer. Since most people rarely need to connect directly to another computer via Wi-Fi, it's best to disable this feature. In Windows XP, open the 'Network Connections' Control Panel applet, right-click your wireless adapter, and choose 'Properties'.

Now select the 'Wireless Networks' tab, and click the 'Advanced' button.

Finally, click 'Access point (infrastructure) networks only'. Be sure to uncheck 'Automatically connect to non-preferred networks'. Now close the dialog box and save your changes. In Vista you don't have to disable ad-hoc networking, since you must manually choose to connect to an ad-hoc network in the first place.