Router search system, router search method and router search program

A transmitter router search apparatus, which is provided for a router search system that examines network connection apparatuses connected to a first network to search for a network connection apparatus that is connected to a second network outside said first network, comprising:

• generating means, for generating an inspection IP packet including search packet information indicating that a destination IP address and a source IP address are defined as IP addresses for a target network connection apparatus to be inspected and said recipient router search apparatus, and that said inspection IP packet is for a router search;
• and
• inspection IP packet transmission means, for transmitting said inspection IP packet.

A recipient router search apparatus, which is provided for a router search system that examines network connection apparatuses connected to a first network to search for a network connection apparatus that is connected to a second network outside said first network, comprising:

• reception means, for receiving an IP packet addressed to the recipient;
• and
• determination means, for determining whether said IP packet received by said reception means is a response IP packet that constitutes a response to said inspection IP packet transmitted by said target network connection apparatus to be inspected, and for, based on the determination results, determining whether said target network connection apparatus is currently operating as a router.

A transmitter router search method, which is provided for a router search method for examining network connection apparatuses connected to a first network to search for a network connection apparatus that is connected to a second network outside said first network, comprising:

• a generating step of generating an IP inspection packet including search packet information indicating that a destination IP address and a source IP address are defined as IP addresses for a target network connection apparatus to be inspected and said recipient router search method, and that said inspection IP packet is for a router search;
• and
• an inspection IP packet transmission step of transmitting said inspection IP packet.

A recipient router search method, which is provided for a router search method for examining network connection apparatuses connected to a first network to search for a network connection apparatus that is connected to a second network outside said first network, comprising:

• a reception step of receiving an IP packet addressed to the recipient;
• and
• a determination step of determining whether said IP packet received at said reception step is a response IP packet that constitutes a response to said inspection IP packet transmitted by said target network connection apparatus to be inspected, and of, based on the determination results, determining whether said target network connection apparatus is currently operating as a router.

A transmitter router search program, which is executed on a first network in order to examine network connection apparatuses connected to said first network to search for a network connection apparatus that is connected to a second network outside said first network, permitting a computer to perform:

• a generating step of generating an inspection IP packet including search packet information) indicating that a destination IP address and a source IP address are defined as IP addresses for a target network connection apparatus to be inspected and said recipient router search program, and that said inspection IP packet is for a router search;
• and
• an inspection IP packet transmission step of transmitting said inspection IP packet.

A recipient router search program, which is executed on a second network in order to examine network connection apparatuses connected to a first network to search for a network connection apparatus that is connected to said second network outside said first network, permitting a computer to perform:

• a reception step of receiving an IP packet addressed to the recipient;
• and
• a determination step of determining whether said IP packet received at said reception step is a response IP packet that constitutes a response to said inspection IP packet transmitted by said target network connection apparatus to be inspected, and of, based on the determination results, determining whether said target network connection apparatus is currently operating as a router.