From Tundrea Adrian-Costin:
TCP/IP Manager is designed to help computer users keep track of their network configuration in different locations. At home or at work, changing network settings is now just one click away.
Here are some of the features of TCP/IP Manager:
Open-source (free to use and redistribute).
Save your network settings in an unlimited number of profiles.
Support for switching TCP/IP settings (including multiple IP/Gateway/DNS servers).
Support for switching proxy settings, computer and workgroup names.
Support for MAC spoofing.
Easy switching between profiles (with tray icon and hotkeys)
Generate batch files from network profiles.
Import current system settings.
Very fast and easy to use interface.
Run at Windows startup.
WebUpdate (complete with news) and statistics modules.
Installer and standalone (7z) versions for both 32-bit and 64-bit platforms.