IPChange: Change your Windows IP number on the fly

Version 3.3, July 15, 2004
Hugh Sparks
http://www.csparks.com

UPDATE: This program is now obsolete.
Please consider using IPSave instead.

IPChange is command line utility that will change the IP number, net mask, gateway and name servers for any network adapter instantly without a reboot. This is particularly valuable for portable owners who move between LANs.

Operating systems

The current version (3.3) works with Windows NT 4.0, Windows 2000, and Windows XP.
IPChange does not work with Windows 98 or Windows 95.

Usage

All possible parameters shown:

	ipchange adapterName ipNumber netMask gateway nameServer1 nameServer2 winsServer1 winsServer2 

Options

With no parameters, ipchange displays usage instructions and a numbered list of adapter names.

You may use the number of the adapter shown on the list instead of the name.

The default netmask is 255.255.255.0

The gateway and name server parameters are optional and default to null settings.

You may accept the default for any setting by using a * in the proper position.

Using * for the adapter name is the same as using 1. (The first adapter.)

Use ? for the ipNumber to request a dynamically assigned number. (DHCP)
This feature is broken.

Use ? for nameServer1 to request a dynamically assigned name server. (DHCP)
This is the default if you omit both nameServer1 and nameServer2.
This feature is broken.

Use ? for winsServer1 to request a dynamically assigned wins server. (DHCP)
This is the default if you omit both winsServer1 and winsServer2.
This feature is broken.

Suggestions

Create a shortcut that runs IPChange with all the parameters for each of your locations:
Right-click on IPChange.exe to create a shortcut with the proper path.
Edit the shortcut properties to add parameters.
You can quickly copy and rename existing shortcuts to make new ones.

Version History

1.0 First release for Windows NT 4.0
2.0 Add support for Windows 2000 and XP
2.1 Add adapter numbering and WINS server specification.
2.2 Support for NT 4.0 restored (2.1 was broken under NT)
3.0 Attempts to support DHCP. NT broken.
3.2 NT fixed again. DHCP still not working.
3.3 Same as 3.2 with DHCP code removed. I gave up.

Downloading

I suggest that you use the most recent (3.3) version. Unless you are trying to help me fix bugs, ignore the DHCP versions.

IPChange 2.2

IPChange 3.0

IPChange 3.2

IPChange 3.3

Examples using the first adapter

Specify ipNumber, mask, gateway and name server

	ipchange 1 192.168.1.13 255.255.255.0 192.168.1.1 192.168.1.2 

Ask for dynamic (DHCP) values: (No longer supported.)

	ipchange 1 ? 

Ask for dynamic IP numbers but specify a name server: (No longer supported.)

	ipchange 1 ? * * 192.168.1.2 

The DHCP problem

IPChange works by calling an undocumented Windows function that is normally used to install IP parameters obtained from a DHCP server. Unfortunately, I have not been able to get the program to work properly when DHCP mode is selected. After using IPChange to switch from static IP numbers to DHCP numbers, everything seems to work: The new IP is assigned, you can ping other machines, surf the net, etc. BUT: after rebooting, the adapter is not configured at all. To get the LAN working again, you must switch back to a static IP using the Control Panel and reboot.

I switched from a static IP to DHCP first using the Control Panel and again after using IPChange. I dumped the entire registry in each case and did a WinDiff comparison. IPChange makes exactly the same registry changes as the Control Panel.

It seems that Windows makes some other file system change that triggers DHCP configuration after reboot. I'm still searching for this clue.

Frequently asked questions

Q: How do I install ipchange?
A: You can put it anywhere you like if you use the full path name when creating a shortcut.

Q: Under Windows 2000 or XP, how do I deal with the bizarre adapter names?
A: Use ipchange with no parameters to display a numbered list of adapters.
You can use the number of the adapter instead of the name.
If you prefer the big name, be sure to include the curly brackets.

Q: What if I have more than two DNS or WINS servers to configure?
A: For now, you only get two of each.

Q: I want to change all sorts of things found in the network control panel...
A: Please send your suggestions.

Q: Why don't you make this program open source?
A: I will do this Real Soon Now.™

Feedback

Hugh Sparks