DHCP Server Attempts to Assign Reserved Addresses (284145)

SYMPTOMS

Under certain conditions, on a scope with numerous exclusions and reservations, a Windows 2000 DHCP server may try to assign reserved addresses to non-reserved clients, and the following behavior may occur:

1. When a DHCP client requests an address that is not in the current scope, the Windows 2000 DHCP server sends a NACK to that address. The client then enters the Discover phase and asks the server to offer an address.
2. The server incorrectly offers a reserved address.
3. The client requests this address.
4. The server realizes that this is a reserved address for another client and sends a NACK to the client.

When the client receives this NACK, it re-enters the Discover phase. The server then incorrectly offers the next reserved address, the client requests it, and the server sends a NACK. DHCP clients that are running Microsoft Windows 98, Microsoft Windows 95 or Microsoft Windows NT stop after a few requests, but a Windows 2000-based client goes through this loop until it receives a valid address. In either case, the client is without a valid address for an extended period of time and becomes non-operational on the network.

   Date       Time    Version        Size      File name
   --------------------------------------------------------
   5/31/2001  03:31p  5.0.2195.3649  270,608   Dhcpssvc.dll