An IP address setting device includes a request packet transmitting unit, a response reception unit, an address information designation unit, and a setting packet transmission unit. The request packet transmitting unit transmits a request packet to a particular multicast address. The request packet requests transmission of an MAC address from each node of the network. The response reception unit receives responses from the nodes to the request packet. Each response includes the MAC address of a corresponding node. Based on the responses received, the address information designation unit designates a node to be set with address information including an IP address and designates the address information. The setting packet transmission unit transmits a setting packet to the particular multicast address. The setting packet includes the address information set by the address information designation unit and the MAC address included in the response from the node.