Embodiments of the present invention provide a method for changing configurations at a client device is presented. The configuration changing method comprises: a) sending a heartbeat request message to a network device over a network, wherein the heartbeat request message carries a current first configuration change code of a client device; b) receiving from the network device a heartbeat response message in accordance with the first configuration change code, wherein the heartbeat response message carries a current second configuration change code of the network device; c) sending, in accordance with the first configuration change code and the second configuration change code, a request message to the network device for synchronizing configurations; d) obtaining configuration synchronization information sent from the network, synchronizing configurations of associated services according to the configuration synchronization information, and updating the first configuration change code in accordance with the results of the configuration synchronization.