This article was previously published under Q285134
When a client and server are on different subnets and the server does not have a scope defined for its local interface, the Windows 2000-based Dynamic Host Configuration Protocol (DHCP) server may not release an Internet Protocol (IP) address when the client sends a DCHP release message.
This problem can occur when the DHCP server evaluates the server's IP address instead of the client's IP address that is requesting the release.
To work around this problem, create a scope on the same IP subnet as the primary DCHP server's interface. The presence of the scope works around the problem. The scope does not have to be active. You can also manually delete the IP leases by using the DHCP Microsoft Management Console (MMC).
Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article.