Patent ID: 8495224

Claim:
A method executed by data processing apparatus, comprising: sending, from a client device, a broadcast request for using a network address specified in the broadcast request; sending, from the client device and without using an address resolution protocol broadcast, a unicast request for each of one or more network address leases stored on the client device, each unicast request being sent to a respective hardware address of a respective server, the respective hardware address of the respective server being specified in a corresponding network address lease; and when a not acknowledged response is received in response to the broadcast request and a hardware address corresponding to one of the one or more network address leases is received in response to the one of the one or more unicast requests: determining whether a network address corresponding to the one of the one or more network address leases is the same as the network address specified in the broadcast request, and upon determining that the network address corresponding to the network address lease is not the same as the network address specified in the broadcast request, broadcasting an address request to use the network address corresponding to the one of the one or more network address leases.