Migrate DHCP Scopes
Applies To: Windows Server 2008
You can use these methods to remove old scopes without disrupting DHCP service to clients on the subnet.
Membership in the Administrators or DHCP Administrators group is the minimum required to complete this procedure.
Create a replacement scope for the subnet before the old scope is deactivated. You can create a replacement scope on a different DHCP server or on the same server. For more information, see Activate a DHCP Scope.
Deactivate a DHCP scope before removing it. After a scope is deactivated, it does not acknowledge lease or renewal requests. DHCP clients will be unable to renew their leases from the deactivated scope and the original server, so the clients will seek new leases from an available DHCP server. For more information, see Deactivate a DHCP Scope.
Superscopes, reservations, and exclusion ranges can be used individually or together to provide a smooth migration of clients from one scope to another. For example, you can create a superscope that contains both a new scope and the original scope that has been targeted for deactivation. If you create an exclusion range of addresses on the original scope, clients with leases that fall within the exclusion range are unable to renew their leases and are assigned leases from the new scope instead. Or, if you add a client reservation in the new scope, when a client attempts to renew its lease from the original scope, the client is instead assigned the address for which a reservation has been configured. For more information, see Create an Exclusion Range of Addresses and Add a Client Reservation.
To manually reconfigure client computers running Windows XP or Windows Vista, you can use ipconfig /release and ipconfig /renew to release an old IP address and acquire a new lease from a replacement scope.