Information processing apparatus communicating with external device via network, and information processing method thereof

A controlling method for an information processing apparatus which communicates with an external device via a network, the method comprising:

• registering an IP address as filter information;
• receiving a packet from the external device;
• obtaining a transmission-source IP address from the received packet;
• judging whether or not the obtained transmission-source IP address has been registered as the filter information, and, when it is judged that the obtained transmission-source IP address has not been registered as the filter information, extracting an interface ID from the transmission-source IP address;
• and
• judging whether or not an IP address having the same interface ID as the extracted interface ID has been registered as the filter information, and, when it is judged that the IP address having the same interface ID has been registered, adding the transmission-source IP address as the filter information.

A non-transitory computer-readable storage medium which stores a program to cause a computer to perform:

• a registering step of registering an IP address as filter information;
• a receiving step of receiving a packet from an external device;
• an obtaining step of obtaining a transmission-source IP address from the received packet;
• an extracting step of judging whether or not the transmission-source IP address obtained in the obtaining step has been registered as the filter information, and, when it is judged that the transmission-source IP address has not been registered as the filter information, extracting an interface ID from the transmission-source IP address;
• and
• an adding step of judging whether or not an IP address having the same interface ID as the interface ID extracted in the extracting step has been registered as the filter information, and, when it is judged that the IP address having the same interface ID has been registered, adding the transmission-source IP address as the filter information.