You can change the IP address of a server using the Network pane of System Preferences or the networksetup tool. When a network address change is detected, no matter how the change happened, changeip is invoked. The tool changeip goes through all configuration files and places where the Serverâ€™s IP address is stored, and changes the address to conform to the new address. The serverâ€™s IP address can be changed without changeip being invoked from the command-line.
In this article: http://docs.info.apple.com/article.html?path=ServerAdmin/10.5/en/c7sa13.html Apple states that you no longer need to use the changeip command with Mac OS X Server: