Data communication system and address setting method for setting an IP address

摘要

To set an IP address to an apparatus existing beyond a router, a first apparatus requests a second apparatus via the router to set an IP address to a third apparatus. Upon reception of the request, the second apparatus sets to the third apparatus the IP address instructed by the first apparatus.

主权项

1. A data communication system including a first apparatus having a valid IP address and a second apparatus having a valid IP address connected with the first apparatus via a router, the system comprising:
a first search unit of the first apparatus configured to transmit a first search request by multicast message for searching for an apparatus in a different subnet via the router; a second search unit of the second apparatus configured to transmit a second search request by limited broadcast message for searching for a third apparatus having no valid IP address that exists in a same subnet as the second apparatus according to the first search request; a first transmitting unit of the third apparatus configured to transmit a response to the second search request, the response comprising a MAC address of the third apparatus; a notification unit of the second apparatus configured to transmit a response to the first search request, the response comprising the MAC address of the third apparatus to the first apparatus; a request unit of the first apparatus configured to transmit a unicast message comprising a setting request including a new IP address and the MAC address of the third apparatus to the second apparatus; and a setting unit of the second apparatus configured to set the new IP address to the third apparatus specified by the MAC address.