Hitachi Metals, Ltd.

Hitachi Cable, Inc.

Shingo Sugawara

Tomoyoshi Tatsumi

Kazuhiro Maeda

Koichiro Seto

Osamu Takada

Toshihiko Murakami

Kazutoshi Kariya

Hitoshi Kuwata

Jyunji Kinoshita

An LP table retains a combination of a physical port and a VLAN identifier in association with a logical port. When a frame is received at the physical port, a table processing unit acquires a logical port based on the LP table. An FDB processing unit learns a source MAC address contained in the received frame in association with the logical port acquired by the table processing unit to an FDB. A plurality of logical ports are set for the physical port by the LP table. A loop prevention unit prohibits frame relay between the plurality of logical ports set for the physical port.

Relay device and relay system

A controller of a tag conversion apparatus configured holds tag conversion information associating addresses of communication apparatuses and information on tags of tagging schemes for network separation, analyzes a frame input from one of the plurality of ports and determine a current tagging scheme of the frame, determines a tagging scheme associated with a destination address of the frame based on the tag conversion information, and converts the frame to a frame of the tagging scheme associated with the destination address based on the tag conversion information when the tagging scheme associated with the destination address and the current tagging scheme are different.

Tag conversion apparatus

A network system has lower switches and upper switches connected to the lower switches. Each of the upper switches includes a connection information notifying means for notifying connected lower switch list informations each of which includes an identification information on each of the lower switches connected to each of the upper switches, to the lower switches connected to each of the upper switches. Each of the lower switches includes a comparison determination means for comparing the connected lower switch list informations notified by the connection information notifying means, in order to determine a connection state between the upper switches and the lower switches.

Network system

A network system includes lower switches and upper switches connected to the lower switches. Each of the upper switches transmits a first notification frame containing a connected lower switch number information indicative of the number of the lower switches connected to each of the upper switches, to the lower switches connected to each of the upper switches. Each of the lower switches configures a link aggregation group for ports which received the first notification frames each of which contains a maximum value of the connected lower switch number information among the connected lower switch number informations contained in the received first notification frames.

A network system includes a plurality of lower switches, a plurality of upper switches, and a link group for interconnecting the plurality of lower switches to the plurality of upper switches in a multipoint-to-multipoint relationship. The link group includes a sub-link for interconnecting the plurality of lower switches to the plurality of upper switches in a point-to-point relationship as one logical link and a main link for interconnecting the plurality of lower switches to the plurality of upper switches in a point-to-multipoint relationship as one logical link. The plurality of lower switches are each set such that a broadcast frame with a broadcast address set as a destination is transmitted to the plurality of upper switches through the sub-link. The plurality of upper switches each receive the broadcast frame and resister a source address contained in the broadcast frame into an FDB of the plurality of upper switches.

Network system including lower and upper switches and link group interconnecting lower switches to upper switches, and method of operating the same

FSs (to) are each connected to IFSs (to). Each of the FSs (to) transmits a setting frame () that includes an FS number to the connected IFSs (to). Each of the IFSs (to) registers, in an LAG setting table, the FS numbers included in the received setting frames () and ports that have received the same in association with each other. Then, each of the IFSs (to) sorts ports (to) in an order of the associated FS numbers, and sets each of LAGs (to) in a common order.

Network relay system and method of automatically setting a network relay system

A network relay system () includes a plurality of IFSs () and a plurality of FSs (). The IFSs (to) are each connected to the FSs (to) through physical lines. In the IFSs (), an LAG is set for ports connected to the FSs (). The IFSs () and the FSs () transmit/receive a detection frame to/from each other, and when the detection frame fails to be received, it is determined that a failure has occurred within the network relay system (). When one of the FSs () determines that a failure has occurred, the one of the FSs () transmits a failure notification frame to the plurality of IFSs (), and each of the plurality of IFSs () excludes the port that has received the failure notification frame from the LAG.

Network relay system and method of controlling a network relay system

A switching hub includes a plurality of ports including receiving ports for receiving a frame from outside and transmitting ports for transmitting the frame to outside, a distributed ID calculation portion for calculating a distributed ID based on the frame received by one of the receiving ports of the plurality of ports and adding the distributed ID to the frame, a first distribution table that stores a port ID for identifying the transmitting port for transmitting the frame associated with the distributed ID to outside, a second distribution table that stores the port ID associated with the distributed ID so that the correspondence relation is different from that of the first distribution table, a distribution table identification information adding portion for adding first table identification information for identifying the first distribution table or second table identification information for identifying the second distribution table to the frame, and a transmission distribution table access portion for obtaining the port ID stored in the first or second distribution table so as to be associated with the distributed ID that is added to the frame by referring to the first distribution table when the first table identification information is added to the frame and by referring to the second distribution table when the second table identification information is added to the frame.

Growing community of inventors

Tsuchiura, Japan

Shingo Sugawara