⻬ Securing the SSID: The next step is to secure the SSID that identifies the
network. A client must know the access point’s SSID in order to join the wireless network. If you can prevent unauthorized clients from discover-
ing the SSID, you can prevent them from accessing your network. There are three things you can do to secure your SSID:
• Change the SSID from the default value yeah, I know I said doing that won’t keep hackers out by itself, but it’s worth doing as part
of a security plan. • Disable the automatic broadcast of the SSID so client computers
have to know the SSID before they can connect. • Disable guest mode, which allows computers to join the network with-
out knowing the SSID.
⻬ Enabling WEP: WEP stands for wired-equivalent privacy, a data-encryption
feature designed to make wireless transmission as secure as transmission over a network cableby scrambling data before transmission. You should
make sure this feature is enabled.
⻬ Using MAC address filtering: MAC address filtering allows you to spec-
ify a list of hardware MAC addresses for the computers that are allowed to access the network. If a computer with a different address tries to join
the network via the access point, the access point will deny access. MAC address filtering is a great idea for wireless networks with a fixed number
of clients. For example, if you set up a wireless network at your office so a few workers can connect their notebook computers, you can specify
the MAC addresses of those computers in the MAC filtering table. Then no other computers can access the network via the access point.
⻬ Placing your access points outside the firewall: The most effective
security technique for wireless networking is to place all of your wire- less access points outside your network’s firewall. That way, all network
traffic from wireless users will have to travel through the firewall to access the network. For more information about firewalls, refer to
Chapter 13.
145
Chapter 10: Setting Up a Wireless Network
146
Part II: Building Your Own Network
Chapter 11
Configuring Client Computers
In This Chapter
䊳
Configuring network connections for Windows clients
䊳
Setting the computer name, description, and workgroup
䊳
Joining a domain
䊳
Setting logon options
䊳
Configuring Windows for wireless networking
B
efore your network setup is complete, you must configure the network’s client computers. In particular, you have to configure each client’s net-
work interface card so it works properly, and you have to install the right pro- tocols so the clients can communicate with other computers on the network.
Fortunately, the task of configuring client computers for the network is child’s play with Windows. For starters, Windows automatically recognizes your net-
work interface card when you start up your computer. All that remains is to make sure that Windows properly installed the network protocols and client
software.
With each version of Windows, Microsoft has simplified the process of config- uring client network support. In this chapter, I describe the steps for configur-
ing networking for Windows XP. Configuration for other versions of Windows is similar.
Configuring Network Connections
Windows automatically detects the presence of a network adapter; normally you don’t have to install device drivers manually for the adapter. When Win-
dows detects a network adapter, it automatically creates a network connec- tion and configures it to support basic networking protocols. However, you
may need to change the configuration of a network connection manually. The following steps show how to configure your network connection:
1. Click Start➪Control Panel to open the Control Panel.
The Control Panel appears.
2. Double-click the Network Connections icon.
The Network Connections folder appears, as shown in Figure 11-1.
3. Right-click the connection that you want to configure, and then choose Properties from the menu that appears.
You can also select the network connection and click Change Settings of This Connection from the task pane. Either way, the Properties dialog
box for the network connection appears, as shown in Figure 11-2.
4. To configure the network adapter card settings, click Configure.
This action summons the Properties dialog box for the network adapter, as shown in Figure 11-3. This dialog box has five tabs that let you config-
ure the NIC:
• General: This tab shows basic information about the NIC, such as
the device type and status. For example, the device shown in Fig- ure 11-3 is a D-Link DFE-530TX+ PCI Adapter it’s installed in slot 3
of the computer’s PCI bus. If you are having trouble with the adapter, you can click the Troubleshoot button to call up the
Windows XP Hardware Troubleshooter. You can also disable the device if it is preventing other components of the computer from
working properly.
Figure 11-1:
The Network
Connections folder.
148
Part II: Building Your Own Network
• Advanced: This tab lets you set a variety of device-specific para-
meters that affect the operation of the NIC. For example, some cards allow you to set the speed parameter typically at 10Mbps or
100Mbps or the number of buffers the card should use. Consult the manual that came with the card before you play around
with any of those settings.
• Driver: This tab displays information about the device driver that
is bound to the NIC and lets you update the driver to a newer ver- sion, roll back the driver to a previously working version, or unin-
stall the driver.
• Resources: With this tab, you can use manual settings to limit the
system resources used by the card — including the memory range, IO range, IRQ, and DMA channels. In the old days, before Plug
and Play cards, you had to configure these settings whenever you installed a card, and it was easy to create resource conflicts.
Windows configures these settings automatically so you should rarely need to fiddle with them.
• Power Management: This tab lets you set power-management
options. You can specify that the network card be shut down when the computer goes into sleep mode — and that the computer wake
up periodically to refresh its network state. When you click OK to dismiss the network adapter’s Properties
dialog box, the network connection’s Properties dialog box closes. You’ll need to click Change Settings for This Connection again to
continue the procedure.
Figure 11-2:
The Properties
dialog box for a
network connection.
149
Chapter 11: Configuring Client Computers
