Installing, Troubleshooting, and Repairing Wireless Networks phần 4 potx

What the Instruction Manual Will Tell You Once you have made your buying decision, let’s take a step back to that part about reading the instruction manual. This part cannot be empha- sized enough. Get a cup of coffee, a soda, or a fresh bottle of water, and take a short break to ensure you know what you are going to be doing. Let’s make this first installation a successful one, so that we can con- centrate on the fun aspects of wireless and become accomplished at it. You should already know whether your access point is config- urable by a web browser once it is hooked up to your Ethernet con- nection, through a serial port, or USB port and special software. Without this information and following the appropriate steps, instal- lation of your access point’s configuration software could fail and have to be re-done, or you could end up losing control of your access point and have to reset it to factory default values and start over. We still live in an age where “plug-and-play” is not a 100 percent reality, and many USB devices and Windows operating systems still require that you install software before connecting devices. If your access point is configurable over Ethernet via web browser or SNMP, you will need to know its default IP address or if it gets an address from a DHCP server. The former is more common, so you can determine a starting point to configure the server. Once you have determined software installation and connectivity, and gained control of the access point with configuration software, you will have to know how you want to set it up. Factors to consider include: ■ Whether to change the default IP address to an address compati- ble with your network ■ How DHCP is going to be handled for clients ■ What channel the access point uses and if you need or want to change it to a nonoverlapping channel (1, 6, or 11) ■ What security method, if any, you are going to use ■ If security is used, establish a security key to be set into the access point and all of your clients Table 7.1 provides a handy worksheet to make note of the default values that come preset in your access point and wireless cards, and your customized values. Chapter 7 108 TABLE 7.1 A handy worksheet to make note of your access point and wireless card configurations. Hardware Installation and Setup 109 Parameter Default Customized Product Make Product Model Firmware Version Configuration Interface USB ____ Ethernet ___ Configuration Method Software ___ Software ___ Web ___ Web ___ SNMP ___ SNMP ___ Configuration Password Read Access Read Access Write Access Write Access SSID Access Point IP Address Access Point Gateway IP Access Point DHCP Source WEP Level Off ___ Off ___ 40/64-bit ___ 40/64-bit ___ 104/128-bit ___ 104/128-bit ___ WEP Key 1 Value ASCII: ASCII: Hex: Hex: WEP Key 2 Value ASCII: ASCII: Hex: Hex: WEP Key 3 Value ASCII: ASCII: Hex: Hex: WEP Key 4 Value ASCII: ASCII: Hex: Hex: DNS Servers Access Point Mode Access Point Access Point Bridge Bridge I suggest starting out with no WEP security key, just to get your clients onto the wireless network for a brief testing period. Once you determine the wireless portion works, then turn on security. This requires that you know if you are going to use 40/64 or 104/128 bit security level, if your key will start out as a string of ASCII charac- ters or hexadecimal (Hex) characters, and which key of the four available you are going to use. These last two items are a source of great confusion when using equipment or operating systems from different vendors. Windows XP numbers the four available WEP keys 0, 1, 2, and 3, while most wireless devices number them 1, 2, 3, and 4 (equivalent to Windows’ 0, 1, 2, and 3, respectively). LinkSys wireless devices and Windows support entering the key in ASCII or Hex, but some operat- ing systems and devices require the key be entered as Hex. There are simple conversion programs that let you enter either ASCII or Hex, and then present the converted values for you—one is available for use on-line at www.powerdog.com. Once you have determined a key value to use, make note of both the ASCII and Hex versions of the key so that you can easily apply the appropriate one in your configuration. Once you have all of this information mapped out for your access point, check the parameters and configuration capabilities of your wire- less adapters. You may have to mix and match WEP key levels and wireless channels to establish a common set of parameters you can use throughout your entire network and for anyone visiting your network. Hardware Configuration Concerns Repeat the process of becoming familiar with your access point for each of the wireless adapters you will apply to your client systems. Be especially aware of USB driver installation requirements before con- necting external client adapters to the systems that will use them. Also, be aware of any input/output (I/O) port address or interrupt request (IRQ) configuration problems with either industry standard architecture (ISA) or peripheral component interconnect (PCI)-based plug-in adapters for desktop systems. The concern over I/O conflicts is especially critical with some system boards that have built-in audio, certain audio cards, and the Linux operating system. You may have to disable or reconfigure your audio device manually to work around conflicts presented by the wireless adapter. Chapter 7 110 Windows 98, 98SE, Me, and XP support true plug-and-play for most compatible PCI devices, and recent versions of Linux do as well, though embedded audio and video chipsets may be stubborn about their plug-and-play capabilities. Check for updates to your sys- tem board basic input/output system (BIOS), and be sure the BIOS settings have plug-and-play enabled. Reset the PCI/non-volatile ran- dom access memory (NVRAM) configuration if necessary to get all the devices properly recognized and reconfigured with any new hard- ware you install. If in doubt about I/O port issues—what they are and how to resolve them—check out my PC configuration book, IRQ, DMA and I/O (3rd edition, IDG, 1999). It may be a little hard to find a copy, but you will swear by it once you get your hands on it! Connecting and Configuring Your Access Point Now that you know what to expect of your access point and client adapters, it is time to start hooking things up. Start with the access point since it is core to your network and central to all the clients that will connect to it over wireless. If the access point uses a USB interface for configuration, install the configuration software and hook up this—and only this—inter- face first, leaving the Ethernet connection unplugged until you have configured the access point for your specific network parameters. If Ethernet is the only way to configure the access point, use your browser or configuration software to begin the configuration. Start with providing or changing the configuration password to prevent anyone from tampering with your access point. Security Note: Anytime there is a security option to control access to a device or its configuration, enable security immediately and change the default password to a unique passphrase. This applies to access point configurations, wireless network service set identifiers (SSIDs), WEP keys, and your local network’s workgroup or network identification (typi- cally ‘Workgroup’ in Windows). In Windows, disable or password-secure any and all file and printer sharing services to prevent hacking and information theft. Hardware Installation and Setup 111 Establish a strong password policy—typically at least 6 to 8 charac- ters long containing a mix of letters, numbers, and punctuation charac- ters if allowed—avoiding common names of family members, pets, etc. Get creative and take a simple word like “plateglass” and substitute a few characters to make it hard to decipher, like pl8gl@ss for example. Connecting and Configuring Your Client Adapters As ubiquitous and promising as (true) plug-and-play is supposed to be, your installation of a wireless adapter may not be as smooth as you would like. I have encountered the simple failure of drivers to install, whether or not a new PC card or USB device has been installed and detected—making for some careful doctoring of Win- dows and a couple of laptops to make everything well. Still, over 80 to 90 percent of today’s PCs will accept any wireless networking adapter you can toss into them, and they will work fine! Barring problems getting your computer and its operating system to recognize the availability of a wireless network adapter, you need to become familiar with the normal parameters a wireless network setup requires. If your system does not initially recognize your chosen wireless adapter and accept the driver installation for it, we probably have a fix for that before you get to the network parameters. PC card wireless adapters. The PC card adapter is the most common wireless network device—catering to the laptop market, but also commonly used in special PCI and ISA adapter card slots for desktop systems. Connecting a wireless card, having the operating system recognize it, and installing the driver software is a simple and successful task over 90 percent of the time. Occasionally, the card manufacturer’s driver software will not install in the operating system, and your only solution is likely to be hooking up to the Internet to search for, download, and try a differ- ent version of the software. Apple Macintosh users will find their choice of wireless adapters limited to the Apple Airport wireless product line. Only a few of the typical wireless network equipment vendors supply wireless card products for the iBook series. While limiting your options, this makes setting up an Apple product for wireless quite a bit easier. Chapter 7 112 If your operating system preference runs to Linux or FreeBSD, you may find drivers for your card provided by the manufacturer, generic drivers with the operating system, or drivers available from open-source contributors. USB wireless adapters. Installing a USB wireless adapter is as simple as installing a PC card—no I/O issues, but you must check the instruction manual to determine if you must install the driver software before connecting the device to your computer. This is a typ- ical scenario for Windows 98SE, Windows Me, and 2000, while Win- dows XP should be able to accommodate post-connection driver installation. PCI and ISA wireless adapters. There are two types of internal plug-in wireless adapter cards: those that have the wireless interface components built onto the board, and those that contain an adapter or slot for a PC card adapter, thus creating a PC card slot in a stan- dard desktop PC I/O socket. The PCI-based cards will be plug-and-play compatible, identified by the system BIOS and then the operating system. These cards cause the operating system to look for a driver, and prompt for a driver to be installed if none exists. ISA-based cards are typically not plug-and-play compatible, so you must know how to install the driver software and configure the card manually. If you are going to experience any hardware configuration issues installing a wireless adapter, they will be with PCI and ISA cards— the classic, legacy headaches plug-and-play is designed to avoid, if plug-and-play cooperates. ISA device conflicts are common and well known. You must know what your current PC configuration is and be able to select unique I/O address and IRQ settings that do not conflict with other devices already in the system, or go through an entire system reconfigura- tion to make all the pieces work together. PCI devices very rarely conflict with other devices because they are configured automatically by the plug-and-play process and prop- er driver software. However, you may find some manufacturers’ products that do not reconfigure themselves based on normal plug- and-play rules, and you will have to manually reconfigure or disable Hardware Installation and Setup 113 them. Users of Linux have encountered problems with some system boards that have built-in audio chipsets that will not reconfigure properly when plug-and-play detects a change in hardware. In these cases, you must check the system BIOS settings and change the con- figuration for the audio components or disable them to get your wire- less adapter to work. The key to success with legacy ISA and some PCI devices is to find, record, and check your system’s current hardware configuration against the requirements of any new devices you are installing. If you know the settings you have to work with, what the proper set- tings should be, and what you can change the settings to, you can make your new device work just fine. Given a choice for legacy/ISA cards, I would suggest using I/O address and IRQ settings typical for those of a normal wired network card—either address 280h or 340h and IRQ 5 or 10—as plug-and-play can work around these fixed set- tings in most system configurations. Configuring Your Wireless Adapter Once your wireless adapter is in place and your operating system recognizes it, you will have access to the wireless network setup parameters to specify network identifications, WEP keys, wireless channels, and standard transmission control protocol (TCP/IP) net- work parameters. For Microsoft Windows and Apple OS X users, these parameters are available in the operating system’s network setup screens. Linux users will have to tinker with specific configu- ration files. Windows XP Microsoft Windows XP was made to be wireless-aware and about as wireless-friendly as possible. When installed, most wireless adapters are at least recognized by plug-and-play in Windows XP followed by a prompt to provide the adapter’s installation CD for driver installation. Although XP will usually automatically install the drivers to make the card functional, often you will have to supply the driver CD for XP to complete the tasks. XP’s driver installation process does not Chapter 7 114 install any of the adapter maker’s special software for configuring or monitoring the adapter’s status. Once XP is done installing drivers, it is recommended that you run the setup program from the driver CD to gain the full benefit of the card. Once the card, its drivers, and its software are installed and ready, XP becomes wireless aware, requiring only that you provide the spe- cific parameters needed to connect to a wireless network. From there, XP’s built-in wireless-aware network support can present you with a new set of network status and configuration screens. When you go to Start, select My Computer, then My Network Places, and select View Network Connections, you will see a listing for “Wireless Network Connection” with an odd-looking antenna icon, similar to that shown in Figure 7.1. Older versions of Windows have no such distinction in their network properties dialogs. Figure 7.1 XP Network Connections window reveals its support for wireless with a distinctive antenna icon representing an installed wireless adapter. Right-click on the new icon, select Properties, and then the new Wireless Networks tab appears—see Figure 7.2. From here, you can preconfigure a known wireless connection or reconfigure an existing connection. To configure your system for a new wireless network, select the Add button to bring up a fresh Wireless Network Properties dialog— see Figure 7.3. Hardware Installation and Setup 115 Figure 7.2 Known active and previously configured wireless networks appear in the Wireless Network Connection Properties dialog. Figure 7.3 The Wireless Network Properties dialog is the place to preconfigure the SSID and encryption parameters required to connect to an access point, or set up an ad-hoc, peer- to-peer wireless connection. Chapter 7 116 In most cases, you will enable data encryption (WEP enabled), not select Network Authentication (Shared mode), and provide a Net- work key in normal text (which is then converted into Hex) of the appropriate length for a 40/64 or 104/128-bit WEP security level. Unless you or your network administrator elect to change which key is used on a daily or weekly basis, you will most often leave the Key index (advanced) setting at 0 (zero). Note: Windows XP numbers WEP keys from 0–3, while the configuration programs of most access points and wireless adapters number the keys 1–4. If your network is not using the default first key, your network administrator should specify if you are to set the Windows XP key index or the wireless adapter configuration, and which specific key number to use in each case. You may assume if the network administrator says to use Key 0 he is making reference to Windows XP (the adapter configura- tion has no key 0). If the administrator says to use Key 4, he means the key setting for the wireless adapter (Windows XP has no key 4). For Win- dows 98–2000, you will use the configuration program provided with your wireless adapter to make these changes. When you have completed the settings, click OK a couple of times in succession to close the dialogs, and then observe the wireless icon in the tool tray and the pop-up status flags that appear as your net- work adapter finds and connects to your access point. Double-clicking the icon will present a dialog similar to Figure 7.4, showing you the relative signal strength and data packet activity of your connection. Right-clicking the wireless adapter icon in the tool tray will pres- ent a small menu with choices to Disable, obtain Status, Repair, View Available Wireless Networks, and Open Network Connections. Selecting Disable will disable the network interface at the software level, blocking all network traffic through the adapter. Status is the same as double-clicking the icon, and will present Windows’ Signal Strength and Packet Information dialog. Repair will invoke the Win- dows IPCONFIG/ RENEW process to make this connection and try to find a DHCP server to obtain new IP address settings in case you have lost your connection. View Available Wireless Networks will present the Wireless Network Selection dialog, shown in Figure 7.5. Open Network Connections presents the complete Network Connec- tion window, as shown in Figure 7.4. Hardware Installation and Setup 117 [...]... by Andrew Corporation It is made in different versions specifically for different wireless frequencies and applications Details of the technology, case study, and product information are available at the Andrew Web site: http://www.andrew.com/products/trans_line/radiax/default.aspx Extending and Maintaining Coverage 143 The exciting thing about Radiax is that, if you were considering installing and. .. problems, and generally expanding the coverage of your wireless system are covered in Chapter 8 Hardware Installation and Setup 131 Summary This is perhaps the most exciting chapter so far—the installation and hopefully first connection of your wireless network components! Yes, it really can be that simple I cannot imagine a more attractive and successful technology coming to the world of personal and business... for 1 24 TABLE 7.2 A handy worksheet to make note of your wireless interface configurations Keep one of these charts handy with data for each network you connect to so that you can remember the SSID and WEP key settings Chapter 7 Parameter Network 1 (Home) Network 2 (Office) Product Make Product Model Firmware Version Configuration Interface USB _ PC Bus _ SSID WEP Level Off _ 40 / 64- bit _ 1 04/ 128-bit... you all available wireless networks, similar to Windows XP’s View Available Wireless Networks dialog From the list, you can select a different network to connect to 121 122 Chapter 7 Figure 7.10 The WMP11’s Encryption dialog is where you set up the WEP encryption level and keys Expect interaction with this dialog to change your WEP key values when you change networks Setting up a wireless network can... _ 40 / 64- bit _ 1 04/ 128-bit _ WEP Key 1 Value ASCII: ASCII: Hex: ASCII: Hex: ASCII: ASCII: Hex: Hex: ASCII: ASCII: Hex: Hex: ASCII: ASCII: Hex: Hex: Infrastructure _ Infrastructure _ Ad Hoc _ Ad Hoc _ WEP Key 2 Value WEP Key 3 Value WEP Key 4 Value Wireless Mode sports stats during the ball game—then you see your neighbor out watering the lawn and you rush out to show him just how cool this wireless. .. support Figure 7.7 is the status screen for a LinkSys WMP11 PCI desktop wireless card showing the connection state to a nearby access point and its MAC address, the associated access points SSID, channel, transfer rate, and signal strength The programs provided with your wireless adapter may be the only way you have to configure them and wireless networking in general, which is the case with the WMP11 card...118 Chapter 7 Figure 7 .4 Click on the wireless network icon in the tool tray to see the status of your wireless connection—at least whether or not packets are flowing in both directions Select the Support tab to see your TCP/IP address information for this connection Figure 7.5 The Connect to Wireless Network dialog shows you the SSID of which wireless networks are available In this view,... Fragmentation Threshold and RTS/CTS Threshold, which are usually left at their default and enabled values—including automatic determination of network access authentication methods These values are provided to customize client and access point interactions for performance, but changing them can reduce your performance when connecting to other networks As you work with your wireless adapter and those in other... to know and preconfigure the SSID for this specific connection to use it Hardware Installation and Setup 119 If you have not previously connected to either of these networks or have not configured a connection, and know the SSID and WEP key for the network, simply type in the key information, then select Connect to make your connection Clicking the Advanced button shown in the Connect to Wireless. .. opens the Wireless Networks tab dialog from the wireless adapter’s properties so that you can reconfigure parameters as needed Here, Microsoft has provided easy access to various complicated settings that were otherwise buried or accessible only from leaving one context and navigating through another Your wireless adapter probably comes with a program to give you more information about your wireless . available WEP keys 0, 1, 2, and 3, while most wireless devices number them 1, 2, 3, and 4 (equivalent to Windows’ 0, 1, 2, and 3, respectively). LinkSys wireless devices and Windows support entering. Address Access Point Gateway IP Access Point DHCP Source WEP Level Off ___ Off ___ 40 / 64- bit ___ 40 / 64- bit ___ 1 04/ 128-bit ___ 1 04/ 128-bit ___ WEP Key 1 Value ASCII: ASCII: Hex: Hex: WEP Key 2 Value ASCII:. 280h or 340 h and IRQ 5 or 10—as plug -and- play can work around these fixed set- tings in most system configurations. Configuring Your Wireless Adapter Once your wireless adapter is in place and your