JP2005184666A - Ring-type network device, redundant method of ring-type network and node device of ring-type network - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that a redundant method responding to the failure of a node or the like can not be applied to the ring-type network device by making several nodes have a virtual physical address in common and making them operate in a complementary manner, since packet communication is established by using only actual physical addresses inherent in the nodes by the ring-type network device. <P>SOLUTION: Since a master and a backup are set for the several nodes and a redundant processor is provided for renewing a TTL value of a packet which is received according to the setting, the several nodes can have an address in common in a network. In consequence, when the master gets out of order, it can be immediately replaced with the backup and the redundant ring-type network can resume operations without changing the address setting. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to redundancy of a network in which a plurality of nodes are connected in a ring shape.

As a conventional ring network configuration method, there are methods according to the following (1) to (4).
(1) Network constituent devices (nodes) are connected in a double ring shape composed of two systems in opposite directions.
(2) Each node periodically transmits its real physical address information on the ring.
(3) Each node receives the real physical address information of other nodes and recognizes the node arrangement order (topology map) on the ring. (4) Each node transmits a topology map when transmitting a packet on the ring. Referring to the two systems, a ring of a system close to the physical address of the destination is selected and transmitted.

  Here, the real physical address is a layer 2 address to which a different address value is assigned for each interface of each node device, such as a MAC address.

  An example of a ring network that adopts the above configuration scheme is RPR (Resilient Packet Ring) described in Non-Patent Document 1 defined by IEEE (The Institute of Electrical and Electronics Engineers, Inc). In RPR, each node device constituting the bidirectional double ring periodically transmits the real physical address information of the own node to the bidirectional ring. Each node receives real physical address information transmitted on the ring from other nodes, and manages the arrangement order of the nodes on the ring as a topology map by accumulating and combining the real physical address information.

The following (R1) to (R5) show how to transmit and relay the RPR real physical address information.
(R1) Each node generates a ring control packet including a TTL (Time To Live) value and real physical address information of the own device, and transmits it on the ring.
(R2) When a ring control packet generated by the own apparatus is transmitted on the ring, the TTL value included in the packet is set to a specified value 255.
(R3) When a ring control packet transmitted from another device is relayed along the ring, the TTL value is decremented by one and relayed.
(R4) The TTL value is referred to when the ring control packet is received, and the number of relay nodes from the transmission source node identified by the real physical address of the transmission source of the packet is calculated.
(R5) A topology map is generated based on the number of relay nodes of each node.

  In RPR, when a transmission source node transmits a user data packet in the ring, the TTL value included in the RPR header of the user data packet is set to the number of hops that does not go around the ring in the generated topology map. , (R5) is searched for the real physical address of the destination node from the topology map generated in (R5), and the ring in the direction close to the destination node is selected and transmitted. Then, the relay node decrements the RPR header TTL value by 1 and relays it. In the destination node of the unicast packet, the packet addressed to the real physical address of the own node terminates at the own node and is not relayed on the ring. Therefore, it becomes possible to reuse the bandwidth in communication between other nodes.

  As described above, since RPR uses only a necessary ring and a minimum section of the double ring for transmission of the packet, it has a feature of high bandwidth utilization efficiency and at the same time, the TTL value of the packet. Since the number of nodes that have passed is reflected, it is possible to discard a packet whose time has elapsed sufficiently since transmission.

IEEE 802.17 Resilient Packet Ring (RPR, IEEE Draft P802.17 / D2.2)

  As a method of taking a redundant configuration in preparation for a device failure in a network, a plurality of gateway devices sharing a virtual IP address and a virtual physical address select one master device, and only the master device performs packet relay, When the master device fails, a method is used in which the backup device transitions to the master device and performs packet relay. Here, the virtual physical address is a layer 2 address used in a limited range of networks, and uses an address value that is not used as a real physical address.

  For example, VRRP (RFC2338 Virtual Router Redundancy Protocol <VRRP>) defined by IETF (Internet Engineering Task Force) is generally used as a network having the above redundant configuration.

  The VRRP has a common virtual physical address and IP address set and VRID (Virtual Router ID) in a group composed of a plurality of VRRP routers on the same LAN. The group constituting the VRRP router is composed of one VR (Virtual Router) master and other VR backups. Only the master forwards packets and responds to ARP (Address Resolution Protocol) requests to a common IP address. . Here, the virtual physical address is represented in hexadecimal by 00-00-5E-00-01- {VRID}.

Only the VRRP advertisement message transmitted from the master is used between the VRRP routers, and the backup does not transmit the message. Here, the content of the VRRP advertisement message includes VRID, priority, IP address, authentication information, and the like. And
(V1) The master multicasts a VRRP advertisement message on the LAN every second.
(V2) If the backup does not receive the VRRP advertisement message for 3 to 4 seconds or more, the backup transits to the master.
(V3) The VRRP router that has transitioned to the master broadcasts an ARP request storing the shared IP address and virtual physical address on the LAN, and causes the layer 2 relay device on the LAN to learn the direction of the virtual physical address. .
The master and backup are activated as follows. Therefore, when the master fails, the backup transitions to a new master after 3 to 4 seconds or more, and packet relay is resumed.

  As described above, in VRRP, a virtual physical address is shared by a plurality of nodes, and a backup transitions to a master as necessary to realize a redundancy method. However, in the above RPR, the topology map is generated only by the real physical address of the ring node. If a plurality of nodes have the same virtual physical address, the topology map does not correspond to the actual node arrangement. Therefore, there is a problem that VRRP cannot be operated on the RPR to make it redundant.

  Not only RPR, but the ring network according to the above (1) to (4) generates a topology map with real physical addresses and does not use virtual physical addresses. Therefore, a redundancy method using virtual physical addresses such as VRRP is applied. Then, when the master node stops, there is a problem that it cannot be replaced by backup.

  The ring network device according to the present invention includes: a receiving unit that receives a packet including a source layer 2 address and a TTL (Time To Live) value that represents an expiration date of the signal; and a result of analyzing the packet based on the result of the analysis A packet processing unit that discards or updates a packet, and a transmission unit that transmits a packet updated by the packet processing unit, a physical address to which a different fixed value is assigned for each device, and a virtual address whose address value can be changed Among them, at least one or more have a plurality of nodes associated with the layer 2 address, and the node associated with the physical address advertises the packet having the physical address as a transmission source from the transmission unit. , One of the plurality of nodes associated with the virtual address is the virtual address One or more nodes are set as backups that are backups of the master, and the master and backup update the TTL value of the received packet based on this setting. A redundant processing unit, and a receiving unit and a transmitting unit of the node are connected in a ring to form a ring network.

  As described above, the ring network device according to the present invention receives a packet including a source layer 2 address and a TTL (Time To Live) value indicating the expiration date of the signal, and analyzes the packet. A packet processing unit that discards or updates the packet based on the result, and a transmission unit that transmits the packet updated by the packet processing unit, and a physical address and an address value to which a different fixed value is assigned for each device. Of the virtual addresses that can be changed, at least one node has a plurality of nodes associated with the layer 2 address, and the node associated with the physical address is configured to send the packet having the physical address as a source. One of the plurality of nodes advertised from the transmission unit and associated with the virtual address is In the master that advertises the packet including the virtual address from the transmission unit to the network, one or more nodes are set as backups that are backups of the master, and the master and backup are TTLs of packets received based on this setting. A redundancy processing unit for updating the value is provided, and the reception unit and the transmission unit of the node are connected in a ring to form a ring network.

  For this reason, even if the master fails, a redundant ring network configuration is possible in which the network can be immediately replaced with a backup and the network can be restarted without changing the address setting.

Embodiment 1 FIG.
FIG. 1 is a block diagram showing an example of a configuration of a ring node apparatus operating as a VRRP router in a network redundancy system according to a first embodiment of the present invention. FIG. It is.

  In FIG. 1, a ring node device 100 is a node constituting a ring network according to the network redundancy system according to the present embodiment, and adjacent ring node devices 100 are doubled by a 0-system ring 130 and a 1-system ring 131, respectively. It is connected. In FIG. 1, the 0-system ring 130 transmits packets from the left node to the right node, and the 1-system ring 131 transmits packets from the right node to the left node for communication. That is, the transmission directions of the 0-system ring 130 and the 1-system ring 131 are opposite. Packets from the 0-system ring 130 are received by the ring interface receiver A101 and transmitted from the ring interface transmitter B122. A packet from the 1-system ring 131 is received by the ring interface receiver B121 and transmitted from the ring interface transmitter A102. The TTL processing unit 103 processes the TTL in the packet received by the ring interface receiving unit A101 and the ring interface receiving unit B121, and passes it to the ring interface transmitting unit A102 and the ring interface transmitting unit B122. The layer 3 switch function unit 104 is a branch line interface having a function of performing relay at the layer 3 level by connecting to a terminal device or another relay device. The RPR interface reception unit 105 performs reception processing of the connection port to the ring network of the layer 3 switch function unit 104, and the RPR interface transmission unit 106 performs transmission processing of the connection port to the ring network of the layer 3 switch function unit 104. . The VRRP processing unit 107 sets in the VRRP state 108 whether the ring node device 100 is a VRRP master or a VRRP backup. The RPR packet processing unit 110 transmits / receives the ring control packet and manages the topology map database 111 and notifies the VRRP processing unit 107 of the VRRP master node state through the VRRP master node state notification path 112. The ring selection unit 113 receives a command from the RPR interface transmission unit 106, refers to the topology map database 111, and selects whether to transmit the transmission packet through the 0-system ring 130 or the 1-system ring 131.

  Next, the master / backup setting and basic operation of the ring node device 100 in the present embodiment will be described. In the ring node device 100 set as the VRRP router, 255 is set as the priority value for the ring node device to be the VRRP master, and a priority value smaller than 255 is set in the VRRP state 108 for the other devices. However, a value other than 255 may be used for the VRRP master, which is not limited). Then, the VRRP master device generates a ring control packet using the virtual physical address and transmits it on the ring. On the other hand, the VRRP backup device does not generate a ring control packet indicating its own device, and relays the ring control packet transmitted from another ring node device to the other ring without changing it.

  When the ring node apparatus 100 is activated and the VRRP processing unit 107 is set to the priority value 255 with reference to the VRRP state 108, the ring node device 100 starts operation as a VRRP master, and the above (( The VRRP advertisement message shown in V1) is periodically transmitted. Generally, “1 second” is used as the value of the period Advert_Timer for transmitting the VRRP advertisement message. When the VRRP processing unit 107 refers to the VRRP state 108 and a priority value smaller than 255 is set, the VRRP backup operation is started after the device is started, and the VRRP advertisement is displayed as shown in (V2) above. If no message is received for a certain period of time, the VRRP processor 107 sets the VRRP state 108 to 255 and makes a transition to the VRRP master in response to a command from the VRRP processing unit 107. The value of the master transition time Master_Down_Timer is set to Adver_Timer × 3 + ((256−VRRP backup priority value) / 256)), and the VRRP backup transitions to a new master in about 3 to 4 seconds after the VRRP master failure.

  Hereafter, the packet in this Embodiment is demonstrated using figures.

  FIG. 2 is an example of a user data packet format on the ring. The RPR packet header 201 is a field shown in FIG. 4, the protocol type 202 is a field containing a protocol type, the service data unit 203 is a field containing user data, and an FCS 204 (Frame Check Sequence) is a field added for error detection. is there. Since the service data unit 203 normally includes an IP packet, and the ring control packet referred to by VRRP in this embodiment is an IP packet, if the inside of the service data unit 203 is examined closely, the contents of the ring control packet are displayed. Can be obtained.

  FIG. 3 is an example of the format of the ring control packet. In the figure, the same reference numerals as those in FIG. 2 denote the same or corresponding parts, and a description thereof will be omitted. The control packet type / Ver 212 is a field containing the type of control packet and the supported RPR protocol version, and the control option 213 is a field containing ring configuration information, etc., and is used when generating a topology map.

  FIG. 4 is an example of the format of the RPR packet header. It consists of TTL 220, attribute information 221 that can identify user data packets and ring control packets, destination physical address 222, source physical address 223, and HEC 224 (Header Error Control) added to detect an error in the header part.

  Next, the operation when the ring node device 100 set as the VRRP router receives a packet by the ring interface reception unit A101 will be described with reference to the flowcharts of FIGS.

  First, in FIG. 5, in S101, the ring interface reception unit A101 refers to the VRRP state 108, and proceeds to S104 if it is a backup, or proceeds to S102 if it is not a backup. In S102, the ring interface receiver A101 refers to the attribute information 221 of the received packet RPR header 201. If the received packet is a ring control packet, the process proceeds to T106, and if not, the process proceeds to S103. In S103, the ring interface receiver A101 refers to the destination physical address 222 of the received packet. If it is a virtual physical address, the process proceeds to T107. If it is a multicast or broadcast address, the process proceeds to T108. In S104, the ring interface receiver A101 refers to the contents of the attribute information 221 of the received packet RPR header. If the received packet is a ring control packet, the process proceeds to T108, and if not, the process proceeds to T109.

  Next, in FIG. 6, T106 proceeds to S106, the ring interface reception unit A101 copies the received packet, sends it to the RPR packet processing unit 110 and the TTL processing unit 103, and ends the processing. In step T107, the ring interface reception unit A101 transmits the received packet to the RPR interface reception unit 105, and the process ends. In step T108, the ring interface reception unit A101 copies the received packet, sends it to the RPR interface reception unit 105 and the TTL processing unit 103, and ends the process. In step T109, the process proceeds to step S109. The ring interface reception unit A101 sends the message to the TTL processing unit 103, and ends the process.

  During S106 to S109, the TTL processing unit 103 refers to the VRRP state 108 when receiving the received packet from the ring interface receiving unit A101, and decrements the RPR packet header TTL value 220 of the received packet by 1 if it is not a backup. When the TTL value becomes 0, the packet is discarded. If the TTL value is other than 0, the packet is sent to the ring interface transmitter on the side opposite to the side that received the packet. If the VRRP state 108 is backup, the TTL value 220 is not manipulated and sent to the ring interface transmitter on the side opposite to the side that received the packet. In FIG. 1, the packet from the ring interface receiver A101 is sent to the ring interface transmitter B122, and the packet from the ring interface receiver B121 is sent to the ring interface transmitter A102. In this embodiment, from the ring interface receiver A101, Since the received packet is received, it is sent to the ring interface transmitter B122.

  In the ring node device 100 set as a VRRP router, the RPR packet processing unit 110 has a ring control packet transmission timer that starts when a ring control packet is transmitted, and a ring control packet is periodically transmitted from the VRRP master device. The Now, the operation of the RPR packet processing unit 110 when the timer expires will be described with reference to the flowchart of FIG.

  First, in S121, the RPR packet processing unit 110 refers to the VRRP state 108. If it is not backup, the process proceeds to S122, and if it is backup, the process proceeds to S123. In S122, the RPR packet processing unit 110 instructs to transmit a ring control packet using the virtual physical address on the topology map database 111, and the process ends. In S123, the RPR packet processing unit 110 restarts the ring control packet transmission timer.

  As described above, the ring control packet is transmitted only from the VRRP master device. This ring control packet is received by other devices on the ring and stored in the topology map database of each device. At this time, the VRRP master device generates and transmits a ring control packet using the virtual physical address, so that another device on the ring can grasp the position of the VRRP virtual physical address.

  In S106 to S109 of FIG. 5, when receiving the ring control packet, the RPR packet processing unit 110 refers to the packet content and stores it in the topology map database 111 as necessary. Further, the RPR packet processing unit 110 monitors whether or not the ring control packet periodically arrives for each device in the topology map database, and if the ring control packet does not arrive for a certain period of time, the device The information on the device is deleted from the topology map database 111. If there is a node determined to be unreachable on the ring from the information included in the control option 213 in the ring control packet, the node is deleted from the topology map database 111.

  In particular, in the VRRP backup device, when the ring control packet does not arrive from the VRRP master device for a certain period of time and the VRRP master device disappears from the topology map database, the VRRP master device is considered to be down, and the VRRP backup device transitions to the VRRP master. And transition. In the present embodiment, the VRRP master device generates a ring control packet using a virtual physical address indicating its own device and transmits it on the ring. Therefore, the virtual physical address ring node on the topology map database 111 in FIG. Is lost to the VRRP processing unit 107 through the VRRP master node state notification path 112, and the VRRP processing unit 107 changes the VRRP state 108 from “backup” to “master”.

  An example of the operation of the ring network having the VRRP router operating as described above will be described below with reference to FIGS.

  FIG. 8 is a diagram showing an example of a ring network configuration having a VRRP router in the present embodiment. The RPR ring node device 301 is a VRRP master, the RPR ring node device 302 is a VRRP backup, and each is a ring node device having a VRRP function configured as shown in FIG. Four of the RPR ring node device 303 to RPR ring node device 306 are ring node devices that do not use the VRRP function. In this embodiment, the description will be made assuming that the ring node device having the configuration shown in FIG. 1 is used. Since the VRRP processing unit 107 and the VRRP state 108 are not used, a ring node apparatus having a configuration excluding the VRRP processing unit 107 and the VRRP state 108 from FIG. 1 may be used, and this is not limited. These six ring node devices are combined as shown in FIG. 8, and a network connected by a double ring is constituted by a clockwise 0-system ring 130 and a counterclockwise 1-system ring 131. The layer 3 switch function unit 309 is a branch line interface having a function of connecting to a terminal device or another relay device and performing relay at the layer 3 level. In the RPR ring node device 301 and the RPR ring node device 302, the layer shown in FIG. This corresponds to a substantial part of the three-switch function unit 104 and is connected to the network 320 in FIG. The real physical address storage unit 310 is a real physical address assigned to the RPR interface of the layer 3 switch function unit 309 (a physical address to which a different value is assigned to each interface of a device connected to the network, a virtual physical address described later) The virtual physical address storage unit 311 stores a virtual physical address that is virtually used by the layer 3 switch function unit 309. The terminal 321 is a terminal connected to the network 320, and the terminal 322 is a terminal connected to the network 320 via a ring node device in the RPR network. In FIG. 8, the packet from the terminal 322 to the terminal 321 is transmitted through the path 135.

  FIG. 9 is an example of a topology map database configuration held by each ring node device in the network of FIG. The node physical address 231 is the address of each ring node device itself, the 0-system upstream adjacent node address 232 is the address of the ring node device adjacent to each ring node device in the counterclockwise direction in FIG. 8, and the 1-system upstream adjacent node address 233 is FIG. 8 shows the address of the ring node device adjacent to each ring node device in the clockwise direction. FIG. 9 shows the real physical addresses of the ring node devices 301 to 306 in FIG. 8 as addresses A to F and the virtual physical address VMA, respectively. In FIG. 8, a ring node device 301 that is a VRRP master transmits a ring control packet of a virtual physical address, and a ring node device 302 that is a VRRP backup does not transmit a ring control packet. Further, the ring node devices 303 to 306 transmit ring control packets of their own real physical addresses. Therefore, the contents as shown in FIG. 9 are stored in the topology map of each ring node device.

  Now, it is assumed that a virtual IP address (referred to as IP_A) is registered as the next hop of the route to the network 320 in the ring node device 305 on the ring. At this time, when the ring node device 305 transmits a packet toward the network 320, a physical address corresponding to the virtual IP address (IP_A) is acquired by ARP or the like. In FIG. 8, the virtual physical address 311 = VMA is acquired. In the ring node device 305, the RPR interface transmission unit 106 acquires the position of the virtual physical address on the ring from the topology map database 111, selects the 0-system ring 130 that is the closer route, and transmits the packet to the ring interface transmission unit B122. And the ring interface transmitter B122 transmits the packet to the ring. As shown in FIG. 9, the ring node device 301 that is a VRRP master has a virtual physical address: VMA, and therefore receives the packet and relays it to the network 320. In this way, the packet is relayed along the path 135 shown in FIG.

  Next, a case where the ring node device 301 has failed will be described with reference to FIGS. In the figure, the same reference numerals as those in FIG. 8 or 9 denote the same or corresponding parts, and the description thereof is omitted.

  In FIG. 10, the ring node device 301 has failed and the ring is disconnected. At this time, a packet from the terminal 322 to the terminal 321 is transmitted through the path 136 in the following procedure.

  When the ring node device 301 in FIG. 10 fails, the ring control packet transmitted from the ring node device 301 is not sent out. As shown above, the ring node of the virtual physical address is obtained from the topology map database of each ring node device. The device disappears. Then, the ring node device 302 that is a VRRP backup transitions to the VRRP master and starts ring control packet transmission using the virtual physical address. Then, the ring node devices 303 to 306 receive the ring control packet from the ring node device 302 and register each in the topology map database 111. Since the contents of the topology map database 111 held by each node at this time are as shown in FIG. 11, the packet transmission from the terminal 322 to the terminal 321 selects the 1-system ring 131 which is a path in which no failure has occurred. , Path 136 is used.

  In this way, the other devices 303 to 306 on the ring can continue to use the same virtual IP address and virtual physical address as the next hop before the occurrence of the failure. That is, redundancy by VRRP has been achieved on the RPR ring of FIGS.

  In the present embodiment, it is assumed that each ring node device advertises each physical address on the ring at intervals of about 5 milliseconds. Therefore, if the timer shown in FIG. 5 is set to about several tens of milliseconds, Since it is sufficient to determine whether or not the node device has disappeared from the network, even if the master device fails, it can be detected in the above time. On the other hand, in the conventional VRRP, as described in (V1) to (V3), since the priority of timeout is set for each node, the VRRP message is transmitted at intervals of 1 second. Since it takes several seconds to determine whether or not it has disappeared from the network, it can be detected earlier by referring to the topology map database 111.

  In this embodiment, a bidirectional double ring is configured, and each ring node device advertises its physical address on the ring. Each ring node device collects the advertisement information and arranges the ring node devices in the order of arrangement. Recognizing (topology map) and referring to the topology map when transmitting packets on the ring, selecting a system ring that is close to the physical address of the destination, and when the ring network is RPR Although shown, it is not limited to this, and any ring network of a method according to the above (1) to (4) can be applied. The same applies to the following embodiments.

  In this embodiment, a plurality of gateway devices sharing a virtual physical address select one master device, only the master device performs packet relay, and the backup device is the master device when the master device fails. Although VRRP is used as an example of a method for performing packet relay by transitioning to a device, the present invention is not limited to this, and only the master device performs packet relay, and if the master device fails, the backup device is the master. Any network can be applied as long as it adopts a redundant configuration in which packet transition is performed by transiting to a device. The same applies to the following embodiments.

  As described above, in the present embodiment, the master generates a ring control packet using a virtual physical address, transmits the packet on the ring, and the backup does not generate a ring control packet indicating its own device, and does not generate another ring node device. Since the transmitted ring control packet is relayed to the other side of the ring without change, packet communication using a virtual physical address is realized on the ring network.

  In the present embodiment, since the ring node device having the same configuration is operated as a master or backup using a virtual physical address on the ring network, even if the master fails, it is immediately replaced with a backup, A redundant network configuration is possible in which the network can be restarted without changing the address setting.

  In addition, since the ring node device on the ring can continue to use the same virtual IP address and virtual physical address as the next hop before and after the occurrence of the failure, redundancy can be performed on the ring network.

  Also, since each node has a topology map, the shortest transmission path can be selected.

In addition, since each node has a topology map, the backup device transitions to the master device when the master device disappears, so it is possible to make a master transition more quickly than when the master transitions after waiting for the VRRP timeout. It becomes possible to shorten the communication interruption time.
Embodiment 2. FIG.
FIG. 12 is a diagram showing an example of a ring network configuration having a VRRP router in the present embodiment. In the figure, the same reference numerals as those in FIG. 8 denote the same or corresponding parts.

  The RPR ring node device 331 is a VRRP master, the RPR ring node device 332 is a VRRP backup, and each is a ring node device having a VRRP function configured as shown in FIG. Three of the RPR ring node devices 333 to RPR ring node device 335 are ring node devices that do not use the VRRP function. In this embodiment, the description will be made assuming that the ring node device having the configuration shown in FIG. 1 is used. Since the VRRP processing unit 107 and the VRRP state 108 are not used, a ring node apparatus having a configuration excluding the VRRP processing unit 107 and the VRRP state 108 from FIG. 1 may be used, and this is not limited. These five ring node devices are combined as shown in FIG. 12, and a network connected by a double ring is constituted by a clockwise 0-system ring 130 and a counterclockwise 1-system ring 131. The layer 3 switch function unit 309 is connected to the network 320 in FIG. The real physical address storage unit 341 and the real physical address storage unit 342 store a real physical address assigned to the RPR interface of the layer 3 switch function unit 309, and the virtual physical address storage unit 340 is virtual in the layer 3 switch function unit 309. Stores the virtual physical address used for. The terminal 321 is a terminal connected to the network 320, and the terminal 322 is a terminal connected to the network 320 via a ring node device in the RPR network. In FIG. 12, the packet from the terminal 322 to the terminal 321 is transmitted through the path 137.

  In the present embodiment, the VRRP backup device 332 generates a ring control packet using the real physical address of the own device and transmits it on the ring. In addition, the VRRP master device 331 generates a ring control packet using the real physical address of the own device, and also generates a ring control packet using the virtual physical address, and transmits each of the ring control packets onto the ring. Then, the VRRP master device 331 subtracts TTL by 2 when relaying the ring control packet transmitted by another ring node device. That is, the same processing as when two ring node devices are relayed is performed.

  Specifically, the operation procedure when the ring node device 100 set as the VRRP router receives the packet in the format of FIGS. 3 and 4 to the ring interface reception unit A101 will be described below with reference to the flowchart of FIG. .

  First, in FIG. 13, in S201, the ring interface reception unit A101 refers to the VRRP state 108, and if it is a master, the process proceeds to S202, and if not, the process proceeds to S204. In S202, the ring interface receiver A101 refers to the attribute information 221 of the received packet RPR header 201. If the received packet is a ring control packet, the process proceeds to T106, and if not, the process proceeds to S203. In S203, the ring interface receiver A101 proceeds to T107 if the destination physical address 222 of the received packet is the virtual physical address or the real physical address of the own device, proceeds to T108 if it is a multicast or broadcast address, and proceeds to T109 otherwise. . In S204, the ring interface receiver A101 refers to the contents of the attribute information 221 in the received packet RPR header. If the received packet is a ring control packet, the process proceeds to T106, and if not, the process proceeds to S205. In S205, the ring interface receiver A101 proceeds to T107 if the destination physical address 222 of the received packet is the actual physical address of the own device, proceeds to T108 if it is a multicast or broadcast address, and proceeds to T109 otherwise. The processing after T106 to T109 is the same as that in FIG.

  Next, the operation procedure of the TTL processing unit 103 in the present embodiment will be described with reference to the flowchart of FIG.

  First, in FIG. 14, in S221, the TTL processing unit 103 refers to the VRRP state 108, and if it is a master, proceeds to S222, otherwise proceeds to S225. In S202, the TTL processing unit 103 refers to the TTL value 220 of the received packet RPR header 201. If “TTL value 220 ≦ 2”, the process proceeds to S224; otherwise, the process proceeds to S223. In S223, the TTL processing unit 103 decrements the TTL value 220 by 2, sends it to the ring interface transmission unit on the side opposite to the side that received the received packet, and ends the processing. In S224, the TTL processing unit 103 discards the received packet and ends the process. In S225, the TTL processing unit 103 refers to the TTL value 220. If “TTL value 220 = 1”, the process proceeds to S224. Otherwise, the process proceeds to S226. In S226, the TTL processing unit 103 decrements the TTL value 220 by 1, sends it to the ring interface transmission unit on the side opposite to the side that received the received packet, and ends the processing.

  The received packet is processed by the RPR interface transmission unit 106, the TTL processing unit 103, and the RPR packet processing unit 110 by the procedure described above. In FIG. 12, a packet from the ring interface reception unit A101 is sent to the ring interface transmission unit B122, and a packet from the ring interface reception unit B121 is sent to the ring interface transmission unit A102, and transmitted to adjacent ring node devices.

  In the present embodiment, when receiving the ring control packet, the RPR packet processing unit 110 reads address information from the packet contents and stores it in the topology map database 111. Further, the RPR packet processing unit 110 monitors whether or not the ring control packet has periodically arrived from each ring node device registered in the topology map database 111, and if the ring control packet does not arrive for a certain period of time. It is assumed that the information of the ring node device is deleted from the topology map database 111 and the ring node device has left the ring. In addition, when there is a ring node device on the topology map database 111 that is determined to be unreachable on the ring from other information included in the control option 213 in the ring control packet, the information on the ring node device is stored in the topology map. Delete from the database 111. In particular, when the virtual physical address disappears from the topology map database, the RPR packet processing unit 110 of the VRRP backup device 332 transitions to the VRRP master.

  That is, in the VRRP backup device 332, when the ring node of the virtual physical address disappears from the topology map database 111, the VRRP processing unit 107 is notified through the VRRP master node state notification path 112, and triggered by this notification, the VRRP processing unit 107 Starts a timer for a time corresponding to the VRRP priority value set in the own device. If a ring node device with a virtual physical address appears in the topology map database 111 during this timer operation, it is notified to the VRRP processing unit 107 via the VRRP master node state notification path 112, and the timer is stopped. If the ring node device of the virtual physical address does not appear and this timer times out, the VRRP state 108 is changed from “backup” to “master”.

  In the present embodiment, in ring node device 100 configured as a VRRP router, RPR packet processing section 110 has a ring control packet transmission timer. The operation of the RPR packet processing unit 110 when the ring control packet transmission timer expires will be described below with reference to the flowchart of FIG.

  First, in S241, the RPR packet processing unit 110 refers to the VRRP state 108. If it is the master, the process proceeds to S244, and if not, the process proceeds to S242. In S242, the RPR packet processing unit 110 instructs to transmit a ring control packet using the real physical address on the topology map database 111, and the process proceeds to S243. In S243, the RPR packet processing unit 110 restarts the ring control packet transmission timer and ends the process. In S244, the RPR packet processing unit 110 generates two ring control packets, a ring control packet using a real physical address and a ring control packet using a virtual physical address, and transmits VRRP master ring control packet to each of them. After executing the process, the process proceeds to S243.

  An example of the ring control packet generated in S244 is shown in FIG. 16, FIG. 17, FIG. 18, and FIG.

  FIG. 16 shows a ring control packet indicating the ring node of the real physical address transmitted to the 0-system ring, and shows an example of the RPR packet header shown in FIG. In the figure, the same reference numerals as those in FIG. 4 denote the same or corresponding parts, and description thereof will be omitted. Here, 255 is stored in the TTL field 220.

  FIG. 17 is a ring control packet indicating the ring node of the virtual physical address transmitted to the 0-system ring, and shows an example of the RPR packet header shown in FIG. In the figure, the same reference numerals as those in FIG. 4 denote the same or corresponding parts, and description thereof will be omitted. Here, 254 is stored in the TTL field 220.

  In the downstream ring node of the 0-system ring that receives the ring control packet from the master device, the ring node of the real physical address and the ring node of the virtual physical address are upstream of the ring node of the virtual physical address on the 0-system ring. Side, real physical address ring nodes are recognized as being adjacent to each other on the downstream side.

  FIG. 18 shows a ring control packet indicating a ring node of a real physical address transmitted to the system 1 ring, and shows an example of the RPR packet header shown in FIG. In the figure, the same reference numerals as those in FIG. 4 denote the same or corresponding parts, and description thereof will be omitted. Here, 254 is stored in the TTL field 220.

  FIG. 19 shows a ring control packet indicating the ring node of the virtual physical address transmitted to the system 1 ring, and shows an example of the RPR packet header shown in FIG. In the figure, the same reference numerals as those in FIG. Here, 255 is stored in the TTL field 220.

  In the downstream ring node of the 1-system ring that receives the ring control packet from the master device, the ring node of the real physical address and the ring node of the virtual physical address are upstream on the 1-system ring. Side, the virtual physical address ring nodes are recognized as being adjacent to each other on the downstream side.

  In FIG. 12, for example, the ring node device 335 has a virtual physical address ring node as a node 1 hop upstream of the system 1 ring, and a real physical address ring node as a node 2 hops upstream. recognize.

  In addition, the VRRP backup device transmits a ring control packet using the real physical address of its own device, as well as other ring nodes that do not enable the VRRP function, and also transmits ring control packets transmitted from other ring nodes. A topology map based on this is generated, and user data packets are transmitted and received as a ring node device having a real physical address.

  Therefore, assuming that the real physical addresses of the ring node devices 331 to 335 are A, B, C, D, and E, respectively, and the virtual physical address is VMA, the contents of the topology map in each ring node device are as shown in FIG. Become.

  In this way, the VRRP master device generates and transmits a ring control packet using the virtual physical address in addition to the ring control packet using the real physical address, so that other ring node devices on the ring can transmit the VRRP virtual physical. It becomes possible to grasp the position of the address.

  Next, a case where the ring node device 301 serving as the VRRP master fails will be described with reference to FIG. In the figure, the same reference numerals as those in FIG. In FIG. 21, a failure has occurred in the ring node device 301, and the ring has been disconnected. At this time, a packet from the terminal 322 to the terminal 321 is transmitted through the path 138 in the following procedure.

  When the ring node device 331 that is the VRRP master fails, the ring node device of the virtual physical address disappears from the topology map database of each ring node device. Then, the ring node device 332 that is a VRRP backup transitions to the VRRP master and starts ring control packet transmission using the virtual physical address. The ring node devices 333 to 335 receive the packet and register it in the topology map database. At the time of route selection addressed to the virtual physical address, the system 1 ring 131 which is a route in which no failure has occurred is selected. Path 138 will be used.

  As described above, in the present embodiment, the master generates a ring control packet using the virtual physical address and the real physical address, transmits the ring control packet onto the ring, and the backup uses the real physical address indicating the own device to transmit the ring control packet. Thus, packet communication using a virtual physical address is realized on the ring network.

  In this embodiment, since the ring node device having the same configuration is operated as a master or backup using a virtual physical address and a real physical address on the ring network, the backup can be performed immediately even if the master fails. Alternatively, a redundant network configuration is possible in which the network can be restarted without changing the address setting.

  In addition, since the ring node device on the ring can continue to use the same virtual IP address and virtual physical address as the next hop before and after the occurrence of the failure, redundancy can be performed on the ring network.

  Also, since each node has a topology map, the shortest transmission path can be selected.

  In addition, since the backup device has a topology map, the backup device transitions to the master device when the master device disappears. Therefore, the backup device transitions to the master device more quickly than waiting for the VRRP timeout to transition to the master device. It becomes possible to shorten the communication interruption time.

Further, since the backup device has a real physical address, the backup device can be directly accessed from another ring node even when the master device is operating.
Embodiment 3 FIG.
In this embodiment, a case where a plurality of virtual physical addresses are used and a VRRP master is installed for each virtual physical address will be described.

FIG. 22 is a block diagram showing an example of the configuration of a ring node device 100A that operates as a VRRP router in a ring network based on the network redundancy method in the present embodiment. In the figure, the same reference numerals as those in FIG.
In FIG. 22, the VRRP state table 109 is set by the VRRP processing unit 107 and holds whether one or more ring node devices 100A are VRRP masters or VRRP backups.

  FIG. 23 shows a configuration example of the VRRP status table 109, which shows the virtual physical address 241 and the VRRP master / backup status of the corresponding ring node device.

  FIG. 24 is a diagram illustrating an example of a ring network configuration having a VRRP router. The RPR ring node device 351 and the RPR ring node device 352 are ring node devices each having a VRRP function having the configuration shown in FIG. Three of the RPR ring node device 353 to RPR ring node device 355 are ring node devices that do not use the VRRP function. In the present embodiment, description will be made assuming that the ring node device having the configuration shown in FIG. 22 is used. Since the VRRP processing unit 107 and the VRRP state table 109 are not used, a ring node device having a configuration excluding the VRRP processing unit 107 and the VRRP state table 109 from FIG. 22 may be used, and this is not limited. As shown in FIG. 24, these five ring node devices are coupled by a clockwise 0-system ring and a counterclockwise 1-system ring to form a network connected by a double ring. The virtual physical address P360, the virtual physical address Q361, and the virtual physical address R362 are virtual physical addresses that are virtually used in VRRP. The terminal J373 is a terminal connected to the ring node device 354, and the terminal K374 is a terminal connected to the ring node device 353. The network T370, the network N1 (371), and the network N2 (372) are networks that are redundantly connected to the ring network at the bottom of the figure. A route 139 and a route 140 are packet transmission routes.

  In FIG. 24, the VRRP master of the virtual IP address IP_P is the node device 351, the VRRP backup is the node device 352, the VRRP master of the virtual IP addresses IP_Q and IP_R is the node device 352, and the VRRP backup is the node device 351. The virtual physical addresses corresponding to the virtual IP addresses IP_P, IP_Q, and IP_R are assumed to be addresses P, Q, and R, respectively.

  Hereinafter, an operation procedure when the ring node apparatus in FIG. 24 receives a packet at the ring interface reception unit A101 in the ring interface reception unit will be described with reference to the flowchart of FIG.

  First, in FIG. 25, in S301, the ring interface receiver A101 refers to the attribute information 221 of the received packet RPR header 201. If the received packet is a ring control packet, the process proceeds to T106, and if not, the process proceeds to S302. In S302, the ring interface receiving unit A101 refers to the destination physical address 222 of the received packet. If it is a multicast or broadcast address, the process proceeds to T108, and otherwise, the process proceeds to S303. In S303, the ring interface receiver A101 refers to the VRRP state table 109. If the destination physical address 222 of the received packet is included, the process proceeds to S304, and otherwise, the process proceeds to T109. In S304, the ring interface reception unit A101 refers to the VRRP state table 109, and proceeds to T107 if the master / backup state 323 corresponding to the destination physical address 222 of the received packet is the master, otherwise proceeds to T109. The processing after T106 to T109 is the same as that in FIG.

  Next, the operation procedure of the TTL processing unit 103 in the present embodiment will be described with reference to the flowchart of FIG.

  First, in FIG. 26, in S321, the TTL processing unit 103 refers to the TTL value 220 of the received packet RPR header 201. If “TTL value 220 ≦ L”, the process proceeds to S323, and if not, the process proceeds to S322. Here, L: the number of ring control packet transmissions is the number of ring control packets transmitted by the own node including the real physical address and the virtual physical address at a time. For example, since the ring node device 351 in FIG. 24 transmits one packet as the real physical address and one packet as the virtual physical address P360, the total number of ring control packet transmissions is 2, and the node device 352 has 1 as the real physical address. Since two packets are transmitted as the packet, virtual physical address Q361 and virtual physical address R362, the number of ring control packet transmissions is 3. In S322, the TTL processing unit 103 decrements the TTL value 220 by L, sends it to the ring interface transmission unit on the side opposite to the side that received the received packet, and ends the processing. In S323, the TTL processing unit 103 discards the received packet and ends the process. The operation of the ring interface transmission unit B122 and the operation when the RPR packet processing unit 110 receives the ring control packet are the same as those in the first embodiment.

  Now, the ring node device having the VRRP function monitors the topology map database 111 of the own device, and if the virtual physical address that is the VRRP backup in the master / backup state 323 disappears from the topology map database 111, Changes to the VRRP master of the virtual physical address, and changes the master / backup status 323 corresponding to the virtual physical address in the VRRP status table 109 of the own device to the master.

  The procedure of the transition shown above will be specifically described below with reference to FIGS. In FIG. 24, the ring node device 352 operates as a VRRP backup device of the virtual IP address IP_P. Here, when the ring node of the virtual physical address P disappears in the topology map database 111 of the node device 352, it is notified to the VRRP processing unit 107, and the VRRP processing unit 107 is triggered by this notification. A timer corresponding to the VRRP priority value for the address IP_P is started. If a ring node device with a virtual physical address appears in the topology map database 111 during this timer operation, it is notified to the VRRP processing unit 107 via the VRRP master node state notification path 112, and the timer is stopped. When the ring node device of the virtual physical address P does not appear and this timer times out, the master / backup status 323 corresponding to the virtual physical address P in the VRRP status table 109 is changed from “backup” to “master”.

  In the present embodiment, in ring node device 100A set as a VRRP router, RPR packet processing section 110 has a ring control packet transmission timer. The operation of the RPR packet processing unit 110 when the ring control packet transmission timer expires will be described below with reference to the flowchart of FIG.

  First, in S341, the RPR packet processing unit 110 loops for each entry in the VRRP status table 109, counts the number N of master entries whose master / backup status 323 is “master”, and proceeds to S342. In S342, the RPR packet processing unit 110 generates a ring control packet for the virtual physical address 322 and the real physical address of each entry whose master / backup status 323 is “master”, and VRRP master / ring control packet for each of them. After executing the transmission process, the process proceeds to S343. In S343, the RPR packet processing unit 110 restarts the ring control packet transmission timer and ends the process.

  The ring control packet generated by the RPR packet processing unit 110 in the flowchart of FIG. 27 will be specifically described below with reference to FIG. In FIG. 24, the ring node device 352 is a VRRP master of the virtual IP addresses IP_Q and IP_R, and is a VRRP backup of the virtual IP address IP_P. The VRRP state table 111 of the ring node device 352 stores a virtual physical address P corresponding to the virtual IP address IP_P and entries of the virtual physical addresses Q and R corresponding to the virtual IP addresses IP_Q and IP_R, respectively. Of these, the master / backup status is “master” because there are two entries, so the number N of master entries counted in S341 is two. Then, the node device 352 generates a total of three ring control packets including the ring control packet of the virtual physical addresses Q and R and the ring control packet of the real physical address, and transmits them on the ring network. The RPR header of the ring control packet transmitted at this time is shown in FIGS.

  FIG. 28 shows a ring control packet indicating a ring node of a real physical address transmitted to the 0-system ring, and shows an example of the RPR packet header shown in FIG. In the figure, the same reference numerals as those in FIG. Here, 255 is stored in the TTL field 220.

  FIGS. 29 and 30 are ring control packets each indicating a ring node of a virtual physical address transmitted to the 0-system ring, and show an example of the RPR packet header shown in FIG. In the figure, the same reference numerals as those in FIG. Here, 253 is stored in the TTL field 220 corresponding to the virtual physical address Q, and 254 is stored in the TTL field 220 corresponding to the virtual physical address R.

  In the downstream ring node of the 0-system ring that receives the ring control packets corresponding to FIGS. 28 to 30, the ring node of the real physical address and the ring nodes of the virtual physical address Q and the virtual physical address R are the 0-system ring. From the upstream side of the ring, it is recognized that the ring node of the virtual physical address Q, the ring node of the virtual physical address R, and the ring node of the real physical address are adjacent to each other in this order.

  FIG. 31 is a ring control packet indicating the ring node of the real physical address transmitted to the system 1 ring, and shows an example of the RPR packet header shown in FIG. In the figure, the same reference numerals as those in FIG. Here, 253 is stored in the TTL field 220.

  FIGS. 32 and 33 are ring control packets each indicating a ring node of a virtual physical address transmitted to the system 1 ring, and show an example of the RPR packet header shown in FIG. In the figure, the same reference numerals as those in FIG. Here, 255 is stored in the TTL field 220 corresponding to the virtual physical address Q, and 254 is stored in the TTL field 220 corresponding to the virtual physical address R.

  In the downstream ring node of the 1-system ring that receives the ring control packets corresponding to FIGS. 31 to 33, the ring node of the real physical address and the ring nodes of the virtual physical address Q and the virtual physical address R are 1-system rings. From the upstream side of the ring, it is recognized that the ring node of the real physical address, the ring node of the virtual physical address R, and the ring node of the virtual physical address Q are adjacent to each other in this order.

  For example, in the ring node device 353 and the ring node device 354 of FIG. 24, if the next hop to the network N1 (371) is registered as the address IP_P and the next hop to the network N2 (372) is registered as the address IP_Q, The node device 353 and the ring node device 354 transmit a packet addressed to the address in the network N1 (371) toward the virtual physical address P, and transmit a packet addressed to the address in the network N2 (372) toward the virtual physical address Q. To do. That is, as shown in FIG. 24, when the terminal 373 transmits a packet addressed to the network N1 (371) and the terminal 374 transmits a packet addressed to the network N2 (372), the path 139 and the path 140 are used, respectively.

  Next, an example when the ring node device 351 that is the VRRP master of the virtual IP address IP_P fails will be described with reference to FIG. In the figure, the same reference numerals as those in FIG.

  In FIG. 34, the ring node device 351 has failed and the ring is disconnected. Therefore, the ring control packet of the virtual physical address P does not arrive at the ring node device 352, and the information of the virtual physical address P is deleted from the topology map database 111 of the ring node device 352. Transition to the VRRP master of address P. The ring node device 352 that has transitioned to the VRRP master generates a ring control packet of real physical addresses and virtual physical addresses P, Q, and R, and transmits the ring control packets on the ring network. The ring node devices 353 to 355 that have received these ring control packets update the topology map database, respectively, so that the packets addressed to the destination network N1 (371) select the 1-system ring and are relayed through the path 141. become.

  As described above, in the present embodiment, the master generates a ring control packet using the virtual physical address and the real physical address, transmits the ring control packet onto the ring, and the backup uses the real physical address indicating the own device to transmit the ring control packet. Thus, packet communication using a virtual physical address is realized on the ring network.

  In this embodiment, since the ring node device having the same configuration is operated as a master or backup using a virtual physical address and a real physical address on the ring network, the backup can be performed immediately even if the master fails. Alternatively, a redundant network configuration is possible in which the network can be restarted without changing the address setting.

  In addition, since the ring node device on the ring can continue to use the same virtual IP address and virtual physical address as the next hop before and after the occurrence of the failure, redundancy can be performed on the ring network.

  Also, since each node has a topology map, the shortest transmission path can be selected.

  In addition, since the backup device has a topology map, the backup device transitions to the master device when the master device disappears, and therefore transitions to the master device more quickly than waiting for the VRRP timeout to transition to the master device. It becomes possible to shorten the communication interruption time.

In addition, since a VRRP master can be defined for each virtual physical address by using means for storing whether the device is a master or a backup for each of one or more virtual physical addresses, Since a plurality of devices serving as gateways can be used at the same time, load distribution by destination address is possible.
Embodiment 4 FIG.
In the present embodiment, the operation when the VRRP master device forcibly transitions to the backup state will be described.

  FIG. 35 is a block diagram showing an example of the configuration of a ring node device 100B that operates as a VRRP router in a ring network based on the network redundancy scheme in the present embodiment. In the figure, the same reference numerals as those in FIG. 1 or FIG. In FIG. 35, the link failure detection unit 113 monitors the link state of ports other than the port operating the VRRP of the layer 3 switch function unit 104, and notifies the VRRP processing unit 107 when link failure is detected.

  FIG. 36 shows an example of a network configuration in which two RPR rings are connected by mutually connecting ring nodes having a VRRP function. The RPR ring node device 401 and the RPR ring node device 406 are VRRP masters, and the RPR ring node device 402 and the RPR ring node device 407 are VRRP backups, each having a VRRP function having the configuration shown in FIG. Six of the RPR ring node devices 403 to 405 and the RPR ring node devices 408 to 410 are ring node devices that do not use the VRRP function. In this embodiment, the ring node devices having the configuration shown in FIG. 35 are used. However, this is not limited.

  The five ring node devices RPR ring node device 401 to RPR ring node device 405 are coupled as shown in FIG. 36 and connected in a double ring by a clockwise 0 system ring and a counterclockwise 1 system ring. Network (hereinafter referred to as network 1). Similarly, five ring node devices of RPR ring node device 406 to RPR ring node device 410 are also coupled as shown in FIG. 36, and a double ring is formed by a clockwise 0 system ring and a counterclockwise 1 system ring. Are connected (hereinafter referred to as network 2). The ring network 1 and the ring network 2 are connected by a link 420 that connects the ring node device 401 and the ring node device 406 and a link 421 that connects the ring node device 402 and the ring node device 407.

  The terminal 411 is a terminal connected to the RPR ring node device 410, and the terminal 322 is a terminal connected to the RPR ring node device 404. A link 420 is a link that connects the ring node device 401 and the ring node device 406, and a link 421 is a link that connects the ring node device 402 and the ring node device 407. In FIG. 36, a packet from the terminal 412 to the terminal 411 is transmitted through the path 423, and a packet from the terminal 411 to the terminal 412 is transmitted through the path 424.

  Now, in FIG. 36, it is assumed that the ring node device 401 is the VRRP master of the virtual IP address IP_41 in the network 1, and the ring node device 406 is the VRRP master of the virtual IP address IP_42 in the network 2. Normally, communication between the network 1 and the network 2 is relayed by the link 420 via the ring node device 401 and the ring node device 406 that are VRRP masters of the respective networks. Therefore, the packet relay between the terminal 412 and the terminal 411 is usually routed via the ring node device 401 and the ring node device 406 which are VRRP masters of the respective networks, and the link 420 connecting these node devices. 423 and path 424.

  Next, an operation when a failure occurs in the link 420 as shown in FIG. 37 will be described. The link failure detection unit 113 of the ring node device 100B illustrated in FIG. 35 monitors the link state of ports other than the port operating the VRRP of the layer 3 switch function unit 104, and if a link disconnection is detected, the VRRP processing unit 107 is notified. Upon receipt of this notification, the VRRP processing unit 107 changes the master / backup status to “backup” for each entry in the VRRP status table 109, and then the RPR packet processing unit 110 transmits a ring control packet. However, the ring control packet of the virtual physical address is not transmitted.

In FIG. 37, the link failure detection unit 113 of the ring node device 401 detects the disconnection of the link 420 and stops transmission of the ring control packet. Therefore, in the topology map database 111 of the ring node apparatus 402 that is a VRRP backup of the network 1, the master backup state 323 of the entry of this virtual physical address is changed to “master”, and the ring control packet of this virtual physical address is changed. Start sending. In exactly the same manner, the ring node device 407 that is a VRRP backup of the network 2 also transitions to the “master”. Therefore, communication from the network 1 to the ring network 2 is relayed using the path 425 via the node device 402.
Similarly, in the network 2, the node device 406 transitions to “backup” and the node device 407 transitions to “master”. Therefore, communication from the network 2 toward the network 1 follows a path 426 via the node device 407. To be relayed.

  As described above, in the present embodiment, the ring failure detection unit 115 of the VRRP master rewrites the VRRP state table by itself and transitions to the VRRP backup when it detects a failure of the link inside or outside the network. Along with this, the “backup” so far changes to “master”, and it becomes possible to relay between both networks in a short interruption time.

3 is a block diagram illustrating an example of a configuration of a ring node device according to Embodiment 1. FIG. 4 is an example of a user data packet format of the ring node device according to the first embodiment. 3 is an example of a ring control packet format of the ring node device according to the first embodiment. 4 is an example of an RPR packet header of the ring node device in the first embodiment. 3 is a flowchart shown in the first embodiment. 3 is a flowchart shown in the first embodiment. 3 is a flowchart shown in the first embodiment. 2 is a diagram illustrating an example of a network configuration in Embodiment 1. FIG. FIG. 9 is a diagram showing an example of a topology map database configuration held by each ring node device in the network of FIG. 8. FIG. 9 is a diagram illustrating a case where a VRRP master fails in the network of FIG. 8. It is a figure which shows the topology map database content which each node hold | maintains in the network of FIG. FIG. 11 is a diagram illustrating an example of a network configuration in a second embodiment. 10 is a flowchart shown in the second embodiment. 10 is a flowchart shown in the second embodiment. 10 is a flowchart shown in the second embodiment. FIG. 10 is an example of an RPR header part of a ring control packet indicating a ring node of a real physical address transmitted to the 0-system ring of the ring node device according to the second embodiment. 10 is an example of an RPR header portion of a ring control packet indicating a ring node of a virtual physical address transmitted to a 0-system ring of the ring node device according to the second embodiment. FIG. 10 is an example of an RPR packet header portion of a ring control packet indicating a ring node of a real physical address transmitted to the first-system ring of the ring node device in the second embodiment. FIG. 10 is an example of an RPR header portion of a ring control packet indicating a ring node of a virtual physical address transmitted to a ring 1 of the ring node device according to the second embodiment. FIG. 13 is a diagram illustrating an example of a topology map database configuration held by each ring node device in the network of FIG. 12. It is a figure which shows the case where a VRRP master fails in the network of FIG. FIG. 10 is a block diagram illustrating an example of a configuration of a ring node device in a third embodiment. It is a structural example of the VRRP state table of FIG. FIG. 10 illustrates an example of a network configuration in a third embodiment. 10 is a flowchart according to the third embodiment. 10 is a flowchart according to the third embodiment. 10 is a flowchart according to the third embodiment. FIG. 16 is an example of an RPR header portion of a ring control packet indicating a ring node having a real physical address transmitted to the 0-system ring of the ring node device according to the third embodiment. FIG. 16 is an example of an RPR packet header of a ring control packet indicating a ring node of a virtual physical address Q transmitted to the 0-system ring of the ring node device in the third embodiment. 15 is an example of an RPR packet header of a ring control packet indicating a ring node of a virtual physical address R transmitted to a 0-system ring of the ring node device according to the third embodiment. FIG. 10 is an example of an RPR header portion of a ring control packet indicating a ring node of a real physical address transmitted to the first-system ring of the ring node device according to the third embodiment. FIG. 16 is an example of an RPR packet header of a ring control packet indicating a ring node of a virtual physical address Q transmitted to the 1-system ring of the ring node device according to the third embodiment. FIG. 16 is an example of an RPR packet header of a ring control packet indicating a ring node of a virtual physical address P transmitted to the 1-system ring of the ring node device according to the third embodiment. FIG. 25 is a diagram illustrating a case where a VRRP master fails in the network of FIG. 24. FIG. 10 is a block diagram illustrating an example of a configuration of a ring node device in a fourth embodiment. FIG. 10 is a diagram illustrating an example of a network configuration in a fourth embodiment. FIG. 37 is a diagram showing a case where a VRRP master fails in the network of FIG. 36.

Explanation of symbols

100 ring node device, 101 ring interface reception unit, 102 ring interface transmission unit, 103 TTL processing unit, 104 layer 3 switch function unit, 105 RPR interface reception unit, 106 RPR interface transmission unit, 107 VRRP processing unit, 108 VRRP state, 110 RPR packet processor, 111 topology map database, 112 VRRP master node status notification path, 121 ring interface receiver, 122 ring interface transmitter, 1300 system ring, 131 1 system ring

Claims (14)

A receiving unit that receives a packet including a source layer 2 address and a TTL (Time To Live) value indicating an expiration date of the signal; a packet processing unit that discards or updates the packet based on a result of analyzing the packet; A transmission unit that transmits the packet updated by the packet processing unit, and at least one of the physical address to which a different fixed value is assigned for each device and a virtual address whose address value can be changed is the layer 2 address And have multiple nodes associated as
The node associated with the physical address advertises the packet having the physical address as a source from the transmission unit,
One node out of a plurality of nodes associated with the virtual address serves as a master that advertises the packet including the virtual address from the transmission unit to the network, and one or more nodes serve as backups for the master. Set,
The master and the backup include a redundancy processing unit that updates the TTL value of the received packet based on this setting,
A ring network apparatus, wherein a reception unit and a transmission unit of the node are connected in a ring to form a ring network. The redundancy processing unit has a table with a virtual address associated with the node as an entry and a master or backup designation as a reference,
2. The ring network device according to claim 1, wherein the packet is advertised from the transmission unit by referring to the table and including the virtual address of an entry whose reference is designated as a master. The redundancy processing unit subtracts, from the TTL value in the received packet, the sum of the number of the physical addresses associated with the own node and the number of the virtual addresses set as the master node. 3. The ring network device according to claim 1, wherein the packet is updated. The node includes a map processing unit that generates and updates a topology map representing an arrangement order of the layer 2 addresses on the network based on a source layer 2 address included in the received packet.
The redundancy processing unit monitors the topology map, and when a virtual address that sets the node as a backup disappears, changes the backup setting to the master, and advertises the packet including the virtual address from the transmission unit. The ring network device according to claim 1, wherein the ring network device is a ring network device. The node includes two each of the transmission unit and the reception unit,
The receiving unit and the transmitting unit form a double ring network by connecting in a circular manner through two routes having opposite packet transmission directions, and the packet processing unit refers to the topology map from the two transmitting units. 5. The ring network device according to claim 4, wherein a shorter route is selected. 6. The ring network device according to claim 1, wherein the node having the redundancy processing unit is a gateway connected to the outside of the ring network. The node having the redundancy processing unit has a detection unit that detects a failure of a link between the own node and the outside of the ring network. When the detection unit detects a failure, the node is set as a master. 7. The ring network device according to claim 6, wherein advertisement of a packet including the virtual address is stopped from the transmission unit, and all master settings are changed to backup. Each node is associated with at least one or more of a physical address to which a different fixed value is assigned for each device as a layer 2 address and a virtual address whose address value can be changed. In a ring network in which each transmitting unit and receiving unit transmit and receive a packet including a source layer 2 address and a TTL value,
One node among the plurality of nodes having the virtual address is set as a master that advertises the packet including the virtual address from the transmission unit to the network, and one or more nodes are set as backups that are backups of the master. Steps,
A node associated with the physical address advertises a packet including the physical address on the network from the transmission unit;
A receiving step in which the receiving unit receives the packet;
A redundancy method for a ring network, wherein a node associated with the virtual address includes a redundancy step of updating a TTL value of a received packet based on the master / backup setting. The redundancy step subtracts a sum of the number of the physical addresses associated with the own node and the number of the virtual addresses set as the master from the TTL value in the received packet. The ring network redundancy method according to claim 8, wherein the ring network is updated. The ring network communicates in a circular manner through two paths with opposite communication directions,
The node generates and updates a topology map representing an arrangement order of the layer 2 addresses on the network based on a source layer 2 address included in the received packet;
10. The ring network redundancy method according to claim 9, wherein the node includes a step of selecting a short transmission path from the two paths based on the topology map. A monitoring step of monitoring its own topology map and monitoring the presence or absence of the virtual address with its own node set as backup;
When detecting the disappearance of the virtual address in the monitoring step, setting the own node as a master corresponding to the virtual address;
The ring network redundancy method according to claim 10, further comprising: 12. The ring network redundancy system according to claim 11, further comprising a step of resetting the node set as a master for an arbitrary virtual address as a backup. A backup in which a plurality of nodes contact each other in a circle, and one of the plurality of nodes sharing the address advertises the packet including the address to other nodes, and one or more nodes are backups of the master In a ring network set to
Nodes sharing the address are
A receiving unit for receiving a packet including an address of a source node and a TTL value indicating an expiration date of a signal;
A packet processing unit for discarding or updating based on a result of analyzing the packet;
A transmission unit for transmitting the packet updated by the packet processing unit;
A ring network node device comprising a redundancy processing unit for updating a TTL value of a received packet based on a master / backup setting. The ring network node device according to claim 13, wherein the redundancy processing unit does not subtract the TTL value of the node set as backup.

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