Most laptops need more than one network configuration: one for the office and one for home (and maybe another for when the user is traveling). At the office, the laptop uses a dynamic Internet Protocol (IP) address and network settings that are assigned by a Dynamic Host Configuration Protocol (DHCP) server. At home, the laptop uses a static IP address and different network settings to communicate on a network and access a shared printer and broadband Internet device. In some cases, a laptop might need to be configured to make a Wi-Fi connection using a Wi-Fi adapter card with a static IP configuration when the user is away from his or her desk; and it might need a DHCP configuration when the laptop is physically connected to the network, or vice versa. When a system uses DHCP to obtain its primary network settings, you can configure alternate network settings for those times when a DHCP server isn't available, such as when the user is traveling or at home. Systems can use alternate configurations in one of two ways: either automatically or user-configured. In meeting rooms or elsewhere on the go, laptop users are also likely to need to connect to networked projectors, a task for which the Connect To A Network Projector Wizard provides an easy solution.
DHCP gives you centralized control over IP addresses and TCP/IP default settings. If the network has a DHCP server, you can assign a dynamic IP address to any of the network adapter cards on a computer. Afterward, you rely on the DHCP server to supply the basic information necessary for TCP/IP networking. To configure dynamic IP addresses, complete these steps:
Click Start and then click Control Panel.
In Control Panel, under the Network And Internet heading, click View Network Status And Tasks.
In the left pane in Network And Sharing Center, click Manage Network Connections.
Network Connections displays a list of all network connections configured for use on the computer. Right-click the connection you want to configure and then select Properties.
Open the Internet Protocol Version 4 (TCP/IPv4) Properties dialog box by double-clicking Internet Protocol Version 4 (TCP/IPv4). You can also select Internet Protocol Version 4 (TCP/IPv4) and then click Properties. This displays the Internet Protocol Version 4 (TCP/IPv4) Properties dialog box, shown in Figure 1.
Figure 1: To use DHCP, configure the computer to obtain an IP address automatically.
Select Obtain An IP Address Automatically. If desired, select Obtain DNS Server Address Automatically. Alternatively, select Use The Following DNS Server Addresses and then type a preferred and alternate Domain Name System (DNS) server address in the fields provided.
When you're finished, click OK.
If your organization or network uses IP Version 6, open the Internet Protocol Version 6 (TCP/IPv6) Properties dialog box by double-clicking Internet Protocol Version 6 (TCP/IPv6). Select Obtain An IP Address Automatically. If desired, select Obtain DNS Server Address Automatically. Alternatively, select Use The Following DNS Server Addresses and then type a preferred and alternate Domain Name System (DNS) server address in the fields provided. Click OK.
Configure alternate private IP addressing and Windows Internet Naming Service (WINS) as necessary.
Only IP Version 4 connections have alternate configurations. When you use DHCP with an IP Version 4 connection, an automatic private IP address (APIPA) is assigned automatically when the DHCP server can't be reached during startup or when the current IP address lease expires. The automatic private IP address is in the range from 169.254.0.1 to 169.254.255.254 with a subnet mask of 255.255.0.0. Because the automatic private IP address configuration does not include a default gateway, DNS, or WINS server settings, a computer using the alternate IP addressing is isolated on a separate network segment in the APIPA range.
If you want to ensure that a computer uses specific IP address and network configuration settings when no DHCP server is available, you need to specify an alternate configuration manually. One of the key reasons for using an alternate configuration is to accommodate laptop users who take their computers home from work. In this way, the user's laptop could be configured to use a dynamically assigned IP address at work and an alternate IP address configuration at home. Before you get started, you might want to ask the users for their home networking settings, including the IP address, gateway, and DNS server addresses required by their service provider.
To configure alternate private IP addresses, complete the following steps:
In the left pane in Network Center, click Manage Network Connections.
Open the Internet Protocol Version 4 (TCP/IPv4) Properties dialog box by double-clicking Internet Protocol Version 4 (TCP/IPv4). You can also select Internet Protocol Version 4 (TCP/IPv4) and then click Properties.
Provided you've already configured the adapter to obtain an IP address automatically, you should be able to click the Alternate Configuration tab, shown in Figure 2.
Figure 2: Use the Alternate Configuration tab to configure private IP addresses for the computer.
On the Alternate Configuration tab, select the User Configured option. Then in the IP Address field, type the IP address you want to use. The IP address you assign to the computer should be a private IP address, and it must not be in use anywhere else at the time the settings are applied. Private IP addresses normally used by computers are in the ranges 10.0.0.1 to 10.255.255.254, 172.16.0.1 to 172.31.255.254, and 192.168.0.1 to 192.168.255.254.
The Subnet Mask field ensures that the computer communicates over the network properly. Windows Vista should insert a default value into this field for the subnet mask. If the network doesn't use subnets, the default value should suffice. However, if it does use subnets, you'll need to change this value as appropriate for the target network.
If the computer needs to access other TCP/IP networks, the Internet, or other subnets, you must specify a default gateway. Type the IP address of the network's default router in the Default Gateway field.
DNS servers are needed for domain name resolution. Type a preferred and alternate DNS server address in the fields provided.
If WINS is used on the network for backward compatibility with previous versions of Windows, configure a preferred and alternate WINS server using the fields provided.
When you're finished, click OK twice and then click Close.
Many meeting rooms and conference centers have networked projectors that are available for use during presentations. To use this type of projector, you must connect your computer to the local area network (LAN) and then access the projector over the network by using the Connect To A Network Projector Wizard. This wizard walks you through the steps of finding projectors on a network and establishing a connection.
You can start and use the Connect To A Network Projector Wizard by following these steps:
Click Start, All Programs, Accessories, Connect To A Network Projector.
If you haven't previously attempted to connect to a network projector and Windows Firewall is active, click Yes to allow the network projector to communicate with the computer through Windows Firewall.
If you want to select from projectors found on the local network, click Choose From Available Network Projectors. The wizard searches for projectors on the network and returns its results along with a list of any projectors you've used recently. Click the projector you want to use, provide the access password for the projector if necessary, and then click Next.
If you know the network address of the projector, click Enter The Projector Address. On the Enter The Network Address Of A Projector page, type the network address of the project, such as http://www.intranet.cpandl.local/projectors/confb-proj1. Enter any required access password and then click Next.
Once you've established a connection to the projector, click Finish to exit the wizard and begin using the projector.
