302 CCNA Wireless Official Exam Certification Guide Figure 16-5 Network Configuration on the Mac OSX Step 3. Select Network. This opens the network configuration page, as shown in Figure 16-5. From here you can select AirPort. Step 4. You can access any already discovered network, create an ad hoc network, or join another network. How the AirPort Extreme Tool Works When you access the main AirPort configuration interface in Mac OSX 10.5 and above, you can disable the card, join networks, and even perform advanced configurations. To ac- cess the main AirPort interface, click the Open Apple icon and select System Preferences > Network. If you want to create a profile, select the Network Name drop-down menu. Here you can choose Join Other Network or Create Network. The Create Network option allows you to set up an ad hoc network of computer-to-computer connectivity without using an AP. By selecting the Join Other Network option, you can enter an SSID and use the drop- down to select any security settings that may be necessary, as shown in Figure 16-6. As an alternative, you can join any networks that AirPort has already discovered by select- ing the Network Name drop-down and choosing one of the networks, as shown in Figure 16-7. If security settings are required, you are prompted. 18_1587202115_ch16.qxp 9/29/08 2:42 PM Page 302 Chapter 16: Wireless Clients 303 Figure 16-6 Wireless Security Settings on Mac OSX Figure 16-7 Selecting the Network Name 18_1587202115_ch16.qxp 9/29/08 2:42 PM Page 303 304 CCNA Wireless Official Exam Certification Guide Figure 16-8 Available Networks in NetworkManager Again, this is not the type of profile you would probably see at work, so you should be fa- miliar with creating a more advanced profile. Note: If you want to try this, I suggest using an Ubuntu Live CD. You can use it to boot your computer to Linux without harming your existing operating system. Best of all, you can download Ubuntu for free at http://www.ubuntu.com. Using Linux to Connect to a Wireless LAN If you or a user within the network that you are involved in is using the Linux operating system, you can certainly use it with a wireless network. Linux has both command-line and GUI interface-type tools for working with WLANs. The command-line tool is called iwconfig. It is similar to the ifconfig that you would use to work with Ethernet interfaces. Although this tool offers many capabilities, Cisco has decided that it is outside the scope of the CCNA Wireless certification. Still, you need to be able to enable a Linux-based de- vice for WLAN access. To do this, you can use NetworkManager. NetworkManager is a graphical user interface (GUI) tool that lets you create wireless pro- files in Linux. It works on a number of different Linux distributions. Finding available net- works is fairly simple. Click the network connection icon in what is equivalent to the System Tray. As shown in Figure 16-8, a number of wireless networks are available. To use one of them, select the radio button next to the network name. You can create a simple profile, one that is most likely used at home, by following these steps: Step 1. Click Create New Wireless Network. Step 2. Enter a network name in the Create New Wireless Network pop-up box. Step 3. Click Connect. 18_1587202115_ch16.qxp 9/29/08 2:42 PM Page 304 Chapter 16: Wireless Clients 305 Figure 16-9 Connecting to Other Wireless Network Figure 16-10 Creating the Profile MySecureNet Configuring a Profile Don’t be alarmed when you see the term “enterprise profile.” It just means that the profile contains more options, most likely security options and such. Setting up an advanced pro- file is not difficult, nor is it too time-consuming. You just have to know the parameters and plug them in. Assuming that you know these parameters, you can select Connect to Other Wireless Network, as shown in Figure 16-9, to begin the process of configuring a profile. Nextyouneedtoenterthenetworknameandusethedrop-downmenutoselectthetype of profile. In Figure 16-10, the network MySecureNet is using WPA2 Enterprise. After you make this selection, a number of other options are available to you, such as the EAP method, key type, identity, and password (see Figure 16-11). The values here are the de- faults, but they can and usually are changed, depending on the security you have set up in your network. 18_1587202115_ch16.qxp 9/29/08 2:42 PM Page 305 306 CCNA Wireless Official Exam Certification Guide Figure 16-11 WPA2 Enterprise Options Another option you have in the advanced settings is Awake Mode. If you place a card into Constant Awake Mode (CAM), the card is active at all times. This consumes more power. How the NetworkManager Tool Works When you click Connect, the NetworkManager tool sends discovery messages using the selected profile parameters. If for some reason an invalid parameter is entered in the Net- workManager tool, a message box appears, requesting the correct parameter. A connection does not take place until the parameters in the profile match. When they match, a connec- tion can take place. When a connection cannot take place due to invalid parameters, it is still added to the list of available networks. However, it indicates a signal power of 0. On the next boot, or if you restart the network daemon, the NetworkManager remembers the parameters. 18_1587202115_ch16.qxp 9/29/08 2:42 PM Page 306 Chapter 16: Wireless Clients 307 Table 16-2 Comparing the WZC and the ADU Capability WZC ADU Scan different channels No Yes Determine which APs are on which channels No Yes Determine the authentication and security configurations of each detected AP No Yes Get RSSI information No Yes Get SNR information No Yes Using the ADU to Connect to a Wireless LAN You have a number of ways to connect to a WLAN. Cisco provides software to manage a single a/b/g wireless card called the Aironet Desktop Utility (ADU). As an administrator, you might be called on to use the Aironet Client Administration Utility (ACAU) to deploy across multiple clients. Additionally, you may use the Cisco Aironet Site Survey Utility (CASSU) when performing site surveys. The following sections cover these topics. Cisco Wireless LAN Adapters Cisco offers enterprise class wireless LAN adapters in the PCI and cardbus form factors. The AIR-CB21AG-X-K9 is a cardbus model, and the AIR-PI21AG-A-K9 is the PCI model. These adapters support most advanced wireless security configurations when you use Cisco software to manage them. You can, however, use the Windows WZC, but it’s better to use the ADU and Aironet System Tray Utility (ASTU) if you want all the features of the cards to be available to you. The ADU has more configuration capability compared to WZC and also includes diagnostic tools, which don’t come with the WZC. With the ADU and a Cisco wireless card, you can ■ Scan different channels. ■ Determine which APs are on which channels. ■ Determine the authentication and security configurations of each detected AP. ■ Get Received Signal Strength Indicator (RSSI) information. ■ Get signal-to-noise ratio (SNR) information. Table 16-2 compares the WZC and the ADU. The Aironet System Tray Utility (ASTU) is a smaller subset of the ADU that lives in your computer’s system tray. Right-click it to access more information or even to launch the ADU. Key Topi c 18_1587202115_ch16.qxp 9/29/08 2:42 PM Page 307 308 CCNA Wireless Official Exam Certification Guide Figure 16-12 Three Options When Installing the ADU Installing the ADU When you install the ADU, you have three options, as shown in Figure 16-12: ■ Install Client Utilities and Driver: Installs the drivers for the card and the ADU software. ■ Install Driver Only: Indicates that you will manage profiles and connect to networks with the WZC. ■ Make Driver Installation Diskette(s): Indicates that you will export these to a re- movable device such as a USB drive and take it with you. In the following example, you will install the drivers and the client utility. The process is pretty simple. It’s best to start by inserting the card. You may see the Win- dows Found New Hardware Wizard, as shown in Figure 16-13. If you see this, close it. You don’t need it. After you have closed the Found New Hardware Wizard, continue with the installation by selecting the type of install you want to perform. In this case, it’s the default option: Install Client Utilities and Driver, as shown previously in Figure 16-12. As the installation progresses (as you click the Next button), you are given the option to install the CASSU, as shown in Figure 16-14. One thing to point out with this site survey utility is that it’s by no means a complete site survey tool because it has no mapping capability. It can, however, be used along with other site survey tools that do provide mapping capability. As a free utility that comes with the purchase of a Cisco network adapter, it’s a good site survey tool. Some customers might not be able to afford the higher-priced tools provided by Ekahau, Wireless Valley, or Air- Magnet, so a free survey tool is better than no survey tool. However, if you can afford the Key Topi c 18_1587202115_ch16.qxp 9/29/08 2:42 PM Page 308 Chapter 16: Wireless Clients 309 Figure 16-13 Found New Hardware Wizard Figure 16-14 Site Survey Utility Install Option higher-priced tools, the CSSU wouldn’t provide any additional benefits over the higher- end tools. The next option you have in the install program is the use of the ADU or third-party tools such as the WZC. This still installs the ADU. Again, you can choose to use the WZC, al- though it’s not recommended. Later you can switch to the ADU by deselecting the Use Windows to configure my wireless network settings option in the WZC, as shown in Figure 16-15. You need to reboot when the install is finished. If there are any open APs, the ADU finds them when the computer is restarted. You will most likely want to create an actual profile with security settings and such. The next section discusses the profile configuration. 18_1587202115_ch16.qxp 9/29/08 2:42 PM Page 309 310 CCNA Wireless Official Exam Certification Guide Figure 16-15 Deselecting WZC as the Default Wireless Network Connection Tool Figure 16-16 Getting Information About a Connection Configuring a Profile In this example, after a reboot, the ADU picked up an open AP and associated with it. The ADU did this because the Windows client was associated with it before the ADU was even installed. To get information on a connection, you can hover the mouse over the ADU icon on the systray, as shown in Figure 16-16. You can also right-click this icon, which is the ASTU, and choose either Show Connection Status or Open Aironet Desktop Utility. Figure 16-17 shows these options as well as oth- ers available in the ASTU. As you become more familiar with the ADU, you will see that these options in the ASTU are merely a subset of what is available in the actual ADU interface. 18_1587202115_ch16.qxp 9/29/08 2:42 PM Page 310 Chapter 16: Wireless Clients 311 Figure 16-17 ASTU Options Figure 16-18 ADU Interface Figure 16-18 shows the ADU interface for a connected profile called Default. If you don’t access the ADU from the ASTU, you can start it by choosing Start > All Pro- grams > Cisco Aironet > Aironet Desktop Utility. If you use the classic Start menu in Windows XP, choose Start > Programs > Cisco Aironet > Aironet Desktop Utility. Connecting to Preferred Networks You can connect to preferred networks that the ADU has scanned for and found. In this case, you can enter security information and save it as a profile, or you can create a profile 18_1587202115_ch16.qxp 9/29/08 2:42 PM Page 311 . Wireless Clients 303 Figure 16-6 Wireless Security Settings on Mac OSX Figure 16-7 Selecting the Network Name 18_1587202115_ch16.qxp 9/29/08 2:42 PM Page 303 304 CCNA Wireless Official Exam Certification. configuration. 18_1587202115_ch16.qxp 9/29/08 2:42 PM Page 309 310 CCNA Wireless Official Exam Certification Guide Figure 16-15 Deselecting WZC as the Default Wireless Network Connection Tool Figure 16-16 Getting. set up in your network. 18_1587202115_ch16.qxp 9/29/08 2:42 PM Page 305 306 CCNA Wireless Official Exam Certification Guide Figure 16-11 WPA2 Enterprise Options Another option you have in the advanced