Here's the scenario:
You are new to Windows 2000 and you are really excited about the many new features of Windows 2000 Server. You are amazed at the wealth of features and options that are arrayed before you.
As a wise administrator, you want to set up a test environment prior to rolling this out to your live environment. You install the basics -- DNS, WINS, DHCP. Suddenly, your pager near explodes with frantic calls as to how the network is getting invalid and conflicting IP addresses. You know that DHCP needs to be authorized in Active Directory to be active and you haven't even installed your first Windows 2000 domain controller. What could the problem be?
DHCP authentication is new to 2000. It requires that all DHCP servers be given permission to operate. These servers are so paranoid that they will actually check every five minutes to ensure their status hasn't changed. The gotcha is that this only works if your DHCP server is a member of a Windows 2000 domain! If DHCP is installed on a stand-alone server, there isn't anyone to authorize it so it just starts handing out addresses.
Here is a quick word of advice: Isolate your test environment from your production network and make sure you have Active Directory up and running BEFORE you fire off Windows 2000 DHCP servers. Your network will thank you.