Using an alternate IP configuration in Windows XP

I noticed Windows XP’s Alternate Configuration feature while using SP2. It allows one network adapter to obtain its IP settings from a DHCP server and fall back to a predefined static configuration if no DHCP server is available.

This is especially useful for a laptop that moves between different networks. I’d been thinking of writing a helper tool to do this!

To set it up:

1. Right-click My Network Places and select Properties.
2. Right-click your network connection and select Properties.
3. Select Internet Protocol (TCP/IP) and click Properties.
4. On the General tab, select Obtain an IP address automatically.
5. Open the Alternate Configuration tab and select User configured. Enter the static IP address, subnet mask, and any required gateway and DNS settings for the other network.
6. Click OK to save the settings and close the properties dialogs.

In my case, DHCP supplies the settings at home, while the alternate configuration contains the static settings I use at work.