Fast fixes for 10 common Wi-Fi problems

Some routers allow the use of Wi-Fi antennas for extended range.

1. I cannot connect to my router. How do I resolve this?
This is a wide-open problem with an almost limitless range of causes and solutions, but here are several actions that might do the trick. First, make sure your router is configured for Dynamic Host Configuration Protocol (DHCP). If it is, try disabling and re-enabling the DHCP function. If that doesn't work, disable wireless security and see if you get a connection; sometimes a mismatched Wired Equivalent Privacy (WEP) key can drop the IP address. You should also check for electrical interference from competing devices such as cordless phones, baby monitors, alarm systems, and microwave ovens. Disable all suspect devices, then recheck your Wi-Fi connection. If all else fails, reboot the router and all computers on your network.

2. What steps should I take to secure my Wi-Fi network?
Routers typically offer at least two common forms of security: WEP, and Wi-Fi Protected Access (WPA) encryption. Both are easy to enable, although you'll get maximum protection from WPA. To activate security, go to your router's browser-based administration tool (the default address for most routers is http://192.168.0.1 or http://192.168.1.1) and look for the wireless security area. WPA requires you to enter a simple security phrase (eight to 63 characters), or, with some routers, a more secure (but much harder to remember) 64-digit key. Similarly, WEP demands that you choose from 64-bit or 128-bit encryption, and enter an alphanumeric hex phrase, with some routers giving you the option to enter a simpler ASCII phrase. In addition to enabling wireless security, you can also disable the broadcasting of the Service Set Identifier (SSID, or network name). Doing so can make the network more difficult for hackers to see. Also, make sure to enable the router's hardware firewall (more on that later), and change the router's default password. And do not enable file sharing, unless you really use it. This will safeguard your personal files from interlopers.

3. How do I open ports on my router?
Certain functions and applications -- personal Web servers, IP Webcams, home FTP servers, and online games -- require that you open ports on your router to allow outside requests to be sent to an internal computer on a home network. This procedure, called port forwarding, is pretty straightforward. First, you'll need to find out which ports you need to open for your particular application or service. Then, you'll open those ports on the router. All models vary slightly, but the process is similar. Open your router's configuration tool, and find a tab labeled Port Forwarding. Enter the service or software name, then type the Start Port and End Port numbers. If you're opening one port, enter the same number in both fields. Select TCP as the protocol, then click OK. Check your router's Web site for instructions for your specific brand or take a look at Port Forward, for help.

4. How do I extend the range of my wireless signal?
Improving a wireless signal is an inexact science that's part voodoo, part trial and error. No two homes are alike, and no two solutions will work for everyone, but here are some common guidelines. First, position your antenna on a high perch clear of obstructions. (The wireless signal radiates down.) Keep in mind that certain things will interfere with the signal: Objects with high water content, metal, and dense building materials such as brick, stucco, and concrete. So avoid blocks of liquid (fish tanks and water coolers), and metal pipes and construction.

If antenna positioning doesn't help, you can get an extender (or "repeater"), such as the Linksys Wireless-G Range Expander WRE54G. Devices like this will boost your range from 50 to 75ft, but they can be tricky because they require setup and configuration. A somewhat easier (if visually less elegant) approach is Wireless Garden's Super Cantenna. This tripod-mounted, high-gain antenna connects to your router and can be pointed at a specific area to amplify the signal. It's easy to set up, but it ain't pretty.

5. How do I automatically connect to a Wi-Fi network without having to manually connect the first time?
If you just want to connect fast to any available network, you can set your notebook to do so automatically. Go to Control Panel > Network Connections and right-click your current wireless network. Then click Properties > Wireless Networks > Advanced. Make sure the radio button next to "Any available network (access point preferred)" is on, then check the box "Automatically connect to non-preferred networks."

6. Which wireless channel should I use?
Wireless 802.11b and 802.11g routers have at least 11 channels, and most routers come set to channel 6 as the default. If you experience interference -- from a neighbor's router, for instance -- you can change your channel to solve the problem. Channels 1, 6, and 11 are non-overlapping channels; other channels overlap a bit. So if your neighbor's network uses channel 6, change your router to 1 or 11. You'll typically find channel settings on the router's basic wireless settings page. Just click the drop-down menu and select an alternate channel, then save the settings.

Set permissions to share your files. (Click for larger image)

7. How do I share files on a wireless network?
First, you'll need to set up a workgroup and make sure that all PCs are assigned to the same workgroup. Next, enable file sharing in Windows. First, right-click on the folder you want to share, choose Sharing and Security from the right-click context menu, then click the Sharing tab. Put checks in the boxes labeled "Share this folder on a network" and "Allow network users to change my files" to enable others to modify the documents. Finally, click OK.

8. Should I allow other people to access my Wi-Fi service? What are the dangers?
Some users see no harm in sharing the Wi-Fi love, giving neighbors and even total strangers free access to the Internet. Others maintain that piggybacking can open their networks to potential danger. In Australia with download (and sometimes upload) quotas on most internet connections, if your wireless network has access to the internet this could result in excessive fees as unauthorised parties use your connection. The decision is yours, but if you choose not to encrypt, make sure to disable file sharing and invest some time into configuring a firewall. If you want to determine whether others are using your unsecured network, most routers have a page that lists all the wireless clients currently connected.

Most people, however, are not comfortable with the idea of allowing just anyone to use their wireless service. In theory, the practice can make your network vulnerable to hackers, since anyone who uses your wireless signal is on your home network. Malevolent users, for instance, could release nasty viruses or hijack your PC, let alone rack up your internet bill. That's not terribly likely, but you should avoid the possibility by using WPA to protect yourself and keep others off your network.

9. Should I worry about packet sniffers grabbing my information when I browse the Web at public hotspots?
Yes, you should at least consider this possibility, although whether you do anything about it depends on the sensitivity of your data and your level of paranoia. Anyone can install packet-sniffing software that will enable him or her to eavesdrop on what you do at a public hotspot. These snoops can read your emails and see what Web sites you visit, but they will not have access to the files on your laptop, unless you have file sharing enabled. Also, they cannot see any messages or Web pages sent over the secure server connections typically used by banks and e-commerce sites (look for https:// in the URL).

If you use a VPN to access your corporate network, you can use it at hotspots to encrypt all transmissions and shield them from packet sniffers. If you don't have a corporate VPN but frequently use public hotspots, you might consider a consumer VPN service.

10. What is a hardware firewall? If my router has one, do I need to run the Windows firewall or other third-party firewall software?
Most wireless routers have a hardware firewall that safeguards the network by providing both incoming and outgoing protection. A hardware firewall will include network address translation (NAT) capabilities that make your PC invisible to anyone trying to attack it. If you enable the hardware firewall, you probably don't need a third-party software firewall. You should still run the Windows firewall, however, because it keeps a low profile and will stop basic worms if your PC gets hit by a drive-by downloader.