Switch device and communication control method

A switch device for relaying flow data in an in-vehicle network in which connection topology and IP addresses are fixedly operated, the flow data being constituted by a frame includes a L2 frame that can be relayed at L2 level and a L3 frame that requires relaying at L3 level, comprising:

• an acquiring section for acquiring correspondence information indicating at least a correspondence relationship between a transmission destination MAC address and a value uniquely determining a transmission destination IP address, a transmission source IP address, transmission destination port information and transmission source port information, the correspondence relationship being fixedly determined in advance, and
• a relay section for acquiring, from the correspondence information, the transmission destination MAC address corresponding to the value, which is included in the L3 frame that is received by the switch device and which uniquely determines the transmission destination IP address, the transmission source IP address, the transmission destination port information and the transmission source port information of the L3 frame, and for performing relay processing at L3 level to transmit the L3 frame including the acquired transmission destination MAC address, wherein
• the switch device further comprises
• a storage section for storing the correspondence information indicating the correspondence relationship fixedly determined in advance, as information that is not updated in processing of the flow data,
• an inspection section for performing inspection processing for determining whether to transmit or discard the L3 frames received by the switch device, and
• a switching section for transmitting the L2 frame received by the switch device to outside, and for switching whether the L3 frames received by the switch device are output to the inspection section or to the relay section, wherein
• the switching section transmits the L2 frame to the outside without checking the IP address, and among the L3 frames, outputs the first L3 frame to the inspection section, and outputs the second and subsequent L3 frames to the relay section,
• in a case that the first L3 frame constituting the flow data has been determined to be a transmission target by the inspection processing, the inspection section does not perform the inspection processing for the second and subsequent L3 frames, and
• the relay section performs the relay processing at L3 level for at least the second and subsequent L3 frames.

A communication control method in a switch device for relaying flow data in an in-vehicle network in which connection topology and IP addresses are fixedly operated, the flow data being constituted by a frame includes a L2 frame that can be relayed at L2 level and a L3 frame that requires relaying at L3 level, comprising:

• a step of acquiring correspondence information indicating at least a correspondence relationship among a transmission destination IP address, a transmission source IP address, transmission destination port information, transmission source port information and a transmission destination MAC address, the correspondence relationship being fixedly determined in advance, and
• a step of acquiring the transmission destination MAC address from the correspondence information on the basis of the transmission destination IP address, the transmission source IP address, the transmission destination port information and the transmission source port information included in the L3 frame that is received by the switch device and then performing relay processing at L3 level to transmit the L3 frame including the acquired transmission destination MAC address, wherein
• the switch device comprises a storage section for storing the correspondence information indicating the correspondence relationship fixedly determined in advance, as information that is not updated in processing of the flow data, and
• the communication control method further comprises
• a step of performing inspection processing for determining whether to submit or discard the L3 frames received by the switch device, and
• a step of performing transmitting the L2 frame received by the switch device to outside, and of performing switching whether the L3 frames received by the switch device are output to the inspection section or to the relay section, wherein
• in the step of performing transmitting and switching, transmitting the L2 frame to the outside without checking the IP address is performed, and among the L3 frames, determining the first L3 frame to be a target for the inspection processing is performed, and determining the second and subsequent L3 frames to be a target for the relay processing is performed,
• in the step of performing inspection processing, in a case that the first L3 frame constituting the flow data has been determined to be a transmission target by the inspection processing, the inspection processing for the second and subsequent L3 frames is not performed, and
• in the step of performing relay processing, the relay processing at L3 level for at least the second and subsequent L3 frames is performed.

A communication control method in a switch device for relaying flow data in an in-vehicle network in which connection topology and IP addresses are fixedly operated, the flow data being constituted by a frame includes a L2 frame that can be relayed at L2 level and a L3 frame that requires relaying at L3 level, comprising:

• a step of acquiring correspondence information indicating at least a correspondence relationship between a transmission destination MAC address and a value uniquely determining a transmission destination IP address, a transmission source IP address, transmission destination port information and transmission source port information, the correspondence relationship being fixedly determined in advance, and
• a step of acquiring, from the correspondence information, the transmission destination MAC address corresponding to the value, which is included in the L3 frame that is received by the switch device and which uniquely determines the transmission destination IP address, the transmission source IP address, the transmission destination port information and the transmission source port information of the L3 frame, and then performing relay processing at L3 level to transmit the L3 frame including the acquired transmission destination MAC address, wherein
• the switch device comprises a storage section for storing the correspondence information indicating the correspondence relationship fixedly determined in advance, as information that is not updated in processing of the flow data, and
• the communication control method further comprises
• a step of performing inspection processing for determining whether to submit or discard the L3 frames received by the switch device, and
• a step of performing transmitting the L2 frame received by the switch device to outside, and of switching whether the L3 frames received by the switch device are output to the inspection section or to the relay section, wherein
• in the step of performing transmitting and switching, transmitting the L2 frame to the outside without checking the IP address is performed, and among the L3 frames, determining the first L3 frame to be a target for the inspection processing is performed, and determining the second and subsequent L3 frames to be a target for the relay processing is performed,
• in the step of performing inspection processing, in a case that the first L3 frame constituting the flow data has been determined to be a transmission target by the inspection processing, the inspection processing for the second and subsequent L3 frames is not performed, and
• in the step of performing relay processing, the relay processing at L3 level for at least the second and subsequent L3 frames is performed.