I recently needed a quick and easy way to change the IP address of my Windows XP workstation. I had to reproduce a problem where the IP address of the client program (which runs on Windows) changes in the middle of a communication session with the server program. Such a thing could happen, for instance, when the client's DHCP lease expires and renewal results in a new address being allocated.

I wanted to do this quickly and easily - the first solution that popped into my head was simply to toggle the configuration of the network interface between using DHCP as normal and a static IP. This can be done via the Network Connections applet in the Control Panel, but is rather involved. It's certainly not quick or easy.

To do the same thing via the command line, use the netsh tool.

After some experimentation, I found that the following two commands were sufficient to give my machine a static IP address and have everything still work ok. The "interface ip set address" command changes the IP to 192.168.1.101 (this address is outside the range allocated by our DHCP server, therefore it will be different to what we had before) and I also had to provide the subnet mask (255.255.255.0), default gateway (192.168.1.5) and a gateway metric. The second command explicitly sets the DNS server to use for name resolution - normally this is done for us by the DHCP server.

netsh interface ip set address "Local Area Connection" static 192.168.1.101 255.255.255.0 192.168.1.5 1
netsh interface ip set dns "Local Area Connection" static 192.1