If the existing network consists of a single computer hooked directly to a cable or DSL modem, you should add a broadband router before continuing. You’ll need a router to share the connection between multiple computers, including computers connecting via the wireless access point.

You can configure your wireless access point for your network in many ways.To leave room in this book for more projects, it’s assumed that you’re adding this new outdoor access point to an existing network. This network already has a working broadband connection connected via a broadband router that provides facilities for sharing the connection between multiple computers.

In geek speak, your network provides DHCP, NAT, and gateway services.

Now it’s time to get the access point configured. The steps are:

Always perform the firmware upgrade through the Ethernet port on the access point, not through the wireless connection. A mis-applied firmware upgrade could result in damage to the access point and a warranty replacement through the manufacturer.

It goes almost without saying that you should always set a new password for your access point so people can’t change the configuration and even disable or hijack it. Make sure that you

change the password for the administrative user (“admin” in most cases) and the user-level passwords, if applicable.

Choose a unique SSID instead of the default that comes with your access point. This reduces confusion for people trying to use your system and allows you to easily identify your system from other wireless signals you may find nearby.

It’s considered good form to provide an SSID that allows someone to contact you if necessary. This is useful if your new access point starts interfering with their signal. You could use a Web site name or even an e-mail address. Or you might use your house or apartment number with or without your street name depending on your expected coverage area. Most systems support SSIDs that are case-sensitive, are 2 to 32 characters long and include most common punctuation characters.

Some examples of SSIDs you could use are: house922, www.socalfreenet.org, myname@fastmail.fm, janewireless. Avoid mixing upper- and lowercase letters to prevent configuration problems.

Wired Equivalent Privacy (WEP) was designed to provide security for wireless networks. If you want to start a debate amongst a group of wireless experts, ask them whether you should use WEP on your wireless network.

Those against will say that WEP can be cracked easily and will cite the seminal paper www.isaac.cs.berkeley.edu/isaac/wep-faq.html in their support and point to one of

Wireless security is a large topic that fills entire books: How Secure is Your Wireless Network? by

Lee Barken is a good starting place.Wireless Security End-to-End by Brian Carter and Russell Shumway is another good book on the subject.

 Install a firewall on each wireless computer. Free firewalls are available from

 You may need to hunt around a little to avoid the paid versions, though. This stops the spread of worms within your wireless LAN and limits the damage if one does get loose.

 Install anti-virus software and keep it updated. In addition to the standard off-the-shelf products, consider smaller companies like www.nod32.com that provide competitive bulk

 Secure your e-mail. Well-known Web mail services like yahoo.com and hotmail.com provide an optional secure logon, but they don’t secure the messages. Consider switching to a provider like fastmail.fm that provides secure Web pages for all your messages, just as your online bank does. If you use an e-mail program, be sure to set the Advanced settings to “This server requires a secure connection (Secure Socket Layer or ‘SSL’)” (or similar) for both outgoing and incoming mail. If your e-mail provider doesn’t support SSL for e-mail, switch to one that does (for example, fastmail.fm again).

 When you use Web sites with sensitive personal data, double-check that they are in ‘secure mode’. Most Web browsers indicate this with a lock icon of some sort, and the URL will generally begin with https:// instead of the usual http://.

 Surf completely anonymously, if you care, by using a third-party-paid service like

Wireless or not, continue to use good security practices like choosing good passwords (a mix of characters and symbols), not reusing the same password in multiple places, and changing your passwords regularly. A good password helper program like www.roboform.com can make this much easier to manage.

Your access point can operate on any of the 11 channels (plus a few more in some countries). However, each channel actually overlaps with two or three channels on either side. Thus only three distinct channels are actually available: 1, 6, and 11. However, recent research suggests that a scheme of 1, 4, 8, and 11 is a reasonable alternative.

Do a mini-war drive in the region your outdoor access point will cover, as described in Chapter 6. Pay particular attention to the channels used by any access points you discover. Choose the least occupied channel for your access point. When the access point is installed, you may need to adjust the channel based on real-world usage. Fortunately, any client computers using your SSID will automatically adjust, so this is not as critical as, say, the SSID you choose or the WEP key you set (if you enable WEP).

When you first configure your access point, it will be on a private LAN consisting of just your computer and the access point, so the settings used don’t matter as long as they’re compatible. However, when you add the access point to your main LAN, it will need to have compatible settings so it is accessible and doesn’t cause conflicts with other devices on the network. The settings needed are:

IP address: A unique address for the access point. Choose a number that’s easy to remember and doesn’t conflict with other devices. For example, many routers use the range from 192.168.0.1 to 192.168.0.254, and often reserve the first number, 192.168.0.1, or last number, 192.168.0.254, for their own address. So you might choose 192.168.0.2 as the address for the access point.

Subnet mask: On most home networks, this will be set to 255.255.255.0.

Gateway: Usually the router acts as the gateway and the address commonly ends in .1. Thus, 192.168.0.1 is a common setting.

DNS server: This value is supplied by your Internet Service Provider (ISP) so refer to their setup instructions. Sometimes the router will forward or cache DNS requests so it may be the same as the gateway value. One way to determine these settings is to find the same settings on a computer on your network. Usually the router supplies these settings automatically via Dynamic Host Configuration Protocol (DHCP). On a Microsoft Windows machine, you can find the value from a command prompt as follows:

C:\>ipconfig /all

Here you can deduce that Internet Protocol (IP) addresses range from 192.168.1.1 to

192.168.1.254 with a subnet mask of 255.255.255.0. The gateway is 192.168.1.1, and the DNS

servers are both the gateway and an alternate of 66.80.131.5.

The DWL-900AP has a configuration wizard that guides you through the installation. It is useful to skip the wizard and configure the settings screen-by-screen to see some of the useful choices that the wizard doesn’t offer and to see how to use them.We’ll walk through these selections in this section.

If the access point has several operating modes, set it to “access point” (also called “infrastructure access point”). Other modes are used in other wireless applications, such as a wireless relay (see Chapter 9), or to connect to another access point. Find the page in your access point to set the SSID, channel, and often a name for the device (see Figure 8-11). The name is sometimes visible to client software, but is mostly useful for maintaining multiple access points as it sometimes gets confusing which one you’re editing when you have several.

Be sure to save the wireless settings, and then find the page to set the LAN settings you calculated. Select the “Static IP Address” setting. If you choose “Dynamic IP Address,” the access point will work when it’s plugged into your network, but it will be hard to find it via the browser to administer it as you won’t know what address to use! (See Figure 8-12.) After you enter and save the LAN values, you’ll need to either adjust your computer network settings to match, or plug both your computer and the access point back into the LAN and continue the configuration from there.

Be aware that your access point is live from here on, so the next step is to change your password. The browser address of the access point will now be the static IP you entered (for example, http://192.168.1.2).

If you can’t get back into the configuration of your access point, you may need to reset it to the factory default settings and start over. The instructions for this are usually on the CD that came with the access point or on the manufacturer’s Web site. The same steps are used if you forget your password.

Change your administration password at the appropriate page and then log back in to continue. At this point, it’s useful to save your configuration settings. Most access points allow you

Speed (Tx/Basic Rate): You can increase the range of your network by decreasing the maximum allowed speed. In theory, it shouldn’t make any difference because Wi-Fi should automatically downgrade to a lower speed if the connection is poor. In practice, it’s useful

to force everyone to a lower speed and save the overhead of all the hunting around for the best speed. Note, though, that you can significantly lower the maximum speed of your network and reduce sharing among users, because now all transmissions will take longer and everyone has to wait until each transmission completes before getting a turn.

If you’re in doubt about what the settings do, change and test them one at a time. Be sure to save your configuration changes so you can revert to a previous version if something stops working.

Don’t be afraid to explore other settings. If the supplied documentation doesn’t explain the settings adequately, a Web search will quickly find more information.

When you’re all done, save the settings to disk, power everything off, take a break, and then come back and do one final test. If possible, find a computer that hasn’t had wireless installed before, then add an adapter and ensure that you can configure it to work with your access point. If you’re using WEP and advanced security measures, this is especially important, as some of the details are hard to get just right.

It’s much easier to work out what’s wrong with all the pieces of the puzzle right in front of you, than when half the gear is up a pole in the rain.