A communication apparatus, comprising: reception means configured to receive a communication start request from another communication apparatus, when the communication apparatus is in a first state; and check means configured to check whether or not the communication start request received by the reception means is addressed to the Internet Protocol IP address of the communication apparatus; shifting means configured to shift a state of the communication apparatus to a second state having power consumption which is larger than that of the first state, in a case where a result of the check by the check means indicates that the communication start request is addressed to the IP address of the communication apparatus; characterized in that the communication apparatus further comprises: acquisition means configured to acquire an IP address in accordance with a Dynamic Host Configuration Protocol DHCP after shifting to the second state; instruction means configured to issue an instruction to the check means to recheck whether or not the communication start request is addressed to the IP address of the communication apparatus in a case where the shifting means has shifted the state of the communication apparatus to the second state and the acquisition means has acquired the IP address, wherein the check means is configured to recheck whether or not the communication start request is addressed to the IP address of the communication apparatus in response to the instruction issued by the instruction means; and transmission means configured to transmit a response, to the communication start request, indicating that communication in accordance with the communication start request is available to the other communication apparatus in a case where a result of the recheck by the check means indicates that the communication start request is addressed to the IP address of the communication apparatus, wherein, if the result of the recheck by the check means indicates that the communication start request is not addressed to the IP address of the communication apparatus, the transmission means is configured to not transmit the response to the other communication apparatus. reception means configured to receive a communication start request from another communication apparatus, when the communication apparatus is in a first state; and check means configured to check whether or not the communication start request received by the reception means is addressed to the Internet Protocol IP address of the communication apparatus; shifting means configured to shift a state of the communication apparatus to a second state having power consumption which is larger than that of the first state, in a case where a result of the check by the check means indicates that the communication start request is addressed to the IP address of the communication apparatus; characterized in that the communication apparatus further comprises: acquisition means configured to acquire an IP address in accordance with a Dynamic Host Configuration Protocol DHCP after shifting to the second state; instruction means configured to issue an instruction to the check means to recheck whether or not the communication start request is addressed to the IP address of the communication apparatus in a case where the shifting means has shifted the state of the communication apparatus to the second state and the acquisition means has acquired the IP address, wherein the check means is configured to recheck whether or not the communication start request is addressed to the IP address of the communication apparatus in response to the instruction issued by the instruction means; and transmission means configured to transmit a response, to the communication start request, indicating that communication in accordance with the communication start request is available to the other communication apparatus in a case where a result of the recheck by the check means indicates that the communication start request is addressed to the IP address of the communication apparatus, acquisition means configured to acquire an IP address in accordance with a Dynamic Host Configuration Protocol DHCP after shifting to the second state; instruction means configured to issue an instruction to the check means to recheck whether or not the communication start request is addressed to the IP address of the communication apparatus in a case where the shifting means has shifted the state of the communication apparatus to the second state and the acquisition means has acquired the IP address, wherein the check means is configured to recheck whether or not the communication start request is addressed to the IP address of the communication apparatus in response to the instruction issued by the instruction means; and transmission means configured to transmit a response, to the communication start request, indicating that communication in accordance with the communication start request is available to the other communication apparatus in a case where a result of the recheck by the check means indicates that the communication start request is addressed to the IP address of the communication apparatus, wherein, if the result of the recheck by the check means indicates that the communication start request is not addressed to the IP address of the communication apparatus, the transmission means is configured to not transmit the response to the other communication apparatus.