Transmitting apparatus and method for maintaining learned information

A transmitting apparatus for connecting a first network to a second network, the first network having a function of storing information including a transmission source address specified in a packet as learned information and using the learned information for controlling a path and a function of deleting information not used for a predetermined time from the learned information, the transmitting apparatus comprising:

• a first communication control unit that controls a communication with the first network;
• a second communication control unit that controls a communication with the second network;
• and
• a protocol converting unit that intermediates between the first communication control unit and the second communication control unit, and performs a protocol conversion to enable a communication between the first network and the second network, wherein
• the second communication control unit detects a transfer path in which a failure has occurred in the second network, and notifies the protocol converting unit of identification information of the transfer path,
• when converting data transmitted from the second network to the first network into a packet in a format that is transferable in the first network, the protocol converting unit stores identification information for identifying a transfer path for the data in the second network and a transmission source address specified in the packet after the conversion in a corresponding manner in a storage unit, and
• upon being notified by the second communication control unit of the identification information of the transfer path in which the failure has occurred, the protocol converting unit obtains a transmission source address corresponding to the notified identification information from the information stored in the storage unit, and transmits a dummy packet in which the obtained transmission source address is specified as the transmission source address to the first network.

A transmitting apparatus for connecting a first network to a second network, the first network having a function of storing information including a transmission source address specified in a packet as learned information and using the learned information for controlling a path and a function of deleting information not used for a predetermined time from the learned information, the transmitting apparatus comprising:

• a first communication control unit that controls a communication with the first network;
• a second communication control unit that controls a communication with the second network;
• and
• a protocol converting unit that intermediates between the first communication control unit and the second communication control unit, and performs a protocol conversion to enable a communication between the first network and the second network, wherein
• when converting data transmitted from the second network to the first network into a packet in a format that is transferable in the first network, the protocol converting unit notifies identification information for identifying a transfer path for the data in the second network and a transmission source address specified in the packet after the conversion,
• the second communication control unit detects a transfer path in which a failure has occurred in the second network, and notifies the first communication control unit of identification information of the transfer path, and
• the first communication control unit stores the identification information of the transfer path and the transmission source address notified by the converting unit in a corresponding manner in a storing unit, obtains a transmission source address corresponding to the identification information of the transfer path notified by the second communication control unit from the information stored in the storing unit, and transmits a dummy packet in which the obtained transmission source address is specified as the transmission source address to the first network.

A method of preventing a loss of learned information due to a failure in a second network in a network configured by connecting a first network to the second network, the first network having a function of storing information including a transmission source address specified in a packet as the learned information and using the learned information for controlling a path and a function of deleting information not used for a predetermined time from the learned information, the method comprising:

• storing, when converting data transmitted from the second network to the first network into a packet in a format that is transferable in the first network, identification information for identifying a transfer path for the data in the second network and a transmission source address specified in the packet after the conversion in a corresponding manner in a storage unit;
• detecting a transfer path in which a failure has occurred in the second network;
• obtaining a transmission source address corresponding to identification information of the transfer path in which the failure is detected by the failure detecting unit from the information stored in the storage unit;
• and
• transmitting a dummy packet in which the obtained transmission source address is specified as the transmission source address to the first network.