Setting Up Alternative TCP/IP Configuration Settings

Mobile users often connect their laptop computers to more than one network. Since most networks use TCP/IP as their local area network protocol and DHCP as the tool for assigning and distributing TCP/IP settings, no interaction or reconfiguration is required on the part of the user when switching between networks. Windows XP Professional simply requests and receives new TCP/IP settings from the DHCP server for each network to which it connects. However, if a mobile user needs to occasionally connect to a network where TCP/IP settings are statically configured, meaning that there is no DHCP server available to handle dynamic TCP/IP configuration, the administrator can configure Windows XP with an alternative TCP/IP configuration. This way, when the user's laptop is connected to a network without a DHCP server, Windows XP will automatically use the alternate TCP/IP configuration settings assigned by the administrator.

The following procedure outlines the steps involved in configuring an alternate TCP/IP configuration on Windows XP Professional.

1. Click on Start, right-click on My Network Places, and select Properties.
2. Right-click on the icon representing the computer's Local Area Connection and select Properties.
3. The Properties dialog for the local area connection appears. Make sure that the General property sheet is selected.
4. Select Internet protocol (TCP/IP) and click on Properties. The Internet Protocol (TCP/IP) Properties dialog appears.
5. Select the Alternate Configuration property sheet.
6. Select the User configured option.
7. Specify the TCP/IP settings as required and click on OK.

Note If an alternate TCP/IP configuration is not set and Windows XP Professional is unable to connect to a DHCP server to receive its TCP/IP settings, Windows XP Professional will assign its own TCP/IP settings. Windows XP Professional will assign itself an IP address in the range of 169.254.0.1-169.254.0.254 with a subnet mask of 255.255.0.0. By providing Windows XP Professional with the ability to automatically assign its own TCP/IP settings, Microsoft has made possible the automatic configuration of small local area networks in which every computer on the network assigns its own TCP/IP setting for a 169.254.0.0 network.