Patent ID: 8886776

Claim:
A communication apparatus comprising: a network interface configured to connect the communication apparatus with a network; a processor; and memory storing a first IP address assigned to the communication apparatus and computer readable instructions, wherein the computer readable instructions cause, when executed by the processor, the communication apparatus and the processor to: obtain first identification information of a particular device located in the network through the network interface and the network, the first identification information being unique to the particular device and in a particular format different from a format of IP addresses; obtain a second IP address assigned to the particular device through the network interface and the network; set the second IP address for use in communication with the particular device; attempt a unicast communication with the particular device by using the second IP address as a destination; determine whether the unicast communication with the particular device failed; generate a new IP address when it is determined that the unicast communication with the particular device has failed, the new IP address containing a network address identical to a network address contained in the first IP address stored in the memory; and broadcast a setting packet to the network, the setting packet comprising the first identification information, the new IP address and particular instructions, wherein the particular instructions causes a recipient device of the setting packet to: determine whether second identification information is identical to the first identification information in the setting packet, the second identification information being unique to the recipient device and in the particular format; and determine whether a DHCP server located in the network assigns a third IP address to the recipient device, and when it is determined that the second identification information is identical to the first identification information and it is determined that the DHCP server assigns the third IP address to the recipient device, assign the new IP address as a static IP address to the recipient device, instead of the third IP address assigned by the DHCP server.