Abstract: A communication device, having a first connecting unit for connecting to a network and a second connecting unit for connecting to an information processing apparatus, receives data from the network through the first connecting unit. The device includes a processing unit that processes the received data and a rejection information registering unit that registers rejection information indicating a specific source, wherein the communication device is not allowed to process data received from the specific source. When receiving data, the device determines whether information indicating a source of the received data is registered in the rejection information registering unit.

Abstract: Address information is requested of a data processing apparatus upon receiving, from the data processing apparatus, data to be transmitted to a network in order to confirm whether an external apparatus is using a specific address. The address information transmitted from the data processing apparatus in response to the request is registered in a communication control apparatus.

Abstract: According to the claimed invention, an image processing method, comprises the steps of storing a plurality of pieces of identification information of a plurality of information processing apparatuses; instructing to change the identification information stored; displaying, when the instructing step gives the instruction to change the identification information, the plurality of pieces of identification information of the plurality of information processing apparatuses stored; searching for information processing apparatuses on the network; displaying a plurality of pieces of identification information of the information processing apparatuses found; and changing identification information selected from the plurality of pieces of identification information displayed in the first displaying step into identification information selected from the plurality of pieces of identification information displayed in the second displaying step.

Abstract: If an address-resolution request message is received from a data processing terminal via an interface connected to the data processing terminal, it is determined whether a physical address corresponding to a target network address of the address-resolution request message has already been registered. If it has been registered, then an address-resolution response message containing the corresponding physical address is created and the created message is transferred to a terminal via the interface.

Abstract: In a communication system of the present invention, second setting information is automatically generated according to first setting information used for performing predetermined processing between at least two devices when the first setting information is set to a first device of the at least two devices, where the second setting information is generated for a second device of the at least two devices. Then, the communication system transmits the automatically-generated second setting information to the second device. Otherwise, the communication system writes the automatically-generated second setting information onto a portable recording medium so that the second device can read the second setting information from the portable recording medium.