Windows 2000's 'Area 51'

An IP limitation bug has been discovered in the Windows 2000 operating system. The new bug seems to misplace directory objects in Windows 2000 Server's Active Directory for every IP that is configured after 51. For most Windows 2000 installations, this won't be an issue. However, for organizations that do their own Internet hosting (such as Web, e-mail, etc.), this could cause problems.

Microsoft claimed that the issue only surfaces if the machine with multiple IP addresses is also a domain controller. As of now, Microsoft does not plan on releasing a patch for this bug, due to a lack of complaints. A Microsoft representative stated, "Microsoft would not likely produce a hot fix for this, given that none of our customers have reported the issue. If a customer does report this, however, we will take it very seriously."

After thorough BugNet testing, it was observed that the 51 IP address limitation occurs within the server itself, no matter how the NICs are arranged.

To be safe, Microsoft recommends that you move your domain controller to another PC. Though the chances are slim that the average Windows 2000 server will run into this problem, it is important to be aware of this constraint before implementing Internet applications.