Patent ID: 7349396

Claim:
A communication device for performing transmission and reception of a content with another communication device having a setting unit that sets a time-to-live of an IP packet for transmitting to a predetermined value, the communication device comprising: a storage unit operable to store therein a common predetermined value that is common to the communication device and the other communication device; an acquiring unit operable to acquire a time-to-live of an IP packet received from the other communication device; a judging unit operable to judge whether the acquired time-to-live is less than or equal to the common predetermined value stored in the storage unit; and a communication unit operable to conduct content transmission/reception with the other communication device only when said judging unit has judged that the acquired time-to-live is less than or equal to the common predetermined value stored in the storage unit, and to not conduct content transmission/reception with the other communication device when said judging unit has judged that the acquired time-to-live is not less than or equal to the common predetermined value stored in the storage unit.