JP2017220812A - Control device, communication system, communication method and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily obtain the redundancy of a route control engine in a configuration in which a centralized control server and a route control engine operate in a cooperative manner.SOLUTION: A control device includes: a route control protocol processing unit which is connected to a transfer device which transfers a packet according to a transfer rule, to communicate with an adjacent router through the transfer device using a predetermined route control protocol to generate route information; and a transfer rule set unit which, based on the route information generated by the route control protocol processing unit, sets to the transfer device the transfer rule to cause the transfer device to perform transfer operation corresponding to the route information. A plurality of route control protocol processing units are arranged, so that each route control protocol processing unit is configured to be communicable with an adjacent router, as a different router arranged on a logical network.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a control device, a communication system, a communication method, and a program, and in particular, a control device, a communication system, and a communication that control a control target network by setting a transfer rule in a transfer device arranged in the control target network. The present invention relates to a method and a program.

  Japanese Patent Application Laid-Open No. 2004-151561 discloses a method for linking an IP network routing protocol between an IP network and an OpenFlow network. According to this document, an OpenFlow controller sets a flow entry in an OpenFlow switch, creates a packet of an IP routing protocol used in the IP network, and sends the IP routing protocol packet to the IP flow through the OpenFlow switch. Send to the network. The OpenFlow controller receives an IP routing protocol packet transmitted from the IP network via the OpenFlow switch, and calculates path information in the IP network based on the received IP routing protocol packet. The route information is stored in the storage means.

  Patent Document 2 discloses a configuration in which the control protocol processing device and the control device operate in cooperation from the viewpoint of reducing the load on the control device corresponding to the above OpenFlow controller. Other non-patent documents include Non-Patent Documents 1 and 2.

  Non-Patent Documents 3 to 7 are documents related to a redundancy method for a path control engine.

JP 2014-160922 A International Publication No. 2015/045275

Kazuya Suzuki, Hideyuki Shimonishi, Akinobu Chiba, Yasuhito Takamiya, Kazushi Suga, Yoshihiko Gimhae, Hideharu Ishii, “OpenFlow Technology and its Applications”, Computer Software, Japan Software Science Society, 2013. Kazuya Suzuki and Shinya Kaneko, “OpenFlow Controller for IP-VPN Realizing Operational Labor Saving”, NEC Technical Journal, Vol. 66, no. 2, pp. 48-51, 2014. [RFC3746] Yang, R.A. Dantu, T .; Anderson and R.M. Gopal, “Forwarding and Control Element Separation (ForCES) Framework”, RFC 3746, Internet Engineering Task Force, 2004. [RFC3623] J. Org. Moy, P.M. Pillay-Esnault and A.M. Lindem, “Graceful OSPF Restart”, RFC 3623, Internet Engineering Task Force, 2003. [RFC 4724] Sangli, E .; Chen, R.A. Fernando, J .; Scudder and Y.M. Rekhter, “Graceful Restart Mechanism for BGP”, RFC 4724, Internet Engineering Task Force, 2007. [Cisco NSR] “OSPF Nonstop Routing”, [online], [Search March 22, 2016], Internet <URL: http://www.cisco.com/c/en/us/td/docs/ios -xml / ios / iproute_ospf / configuration / 15-sy / iro-15-sy-book / iro-nsr-ospf.html> [Juniper NSR] Nonstop Active Routing Concepts, [online], [Search March 22, 2016], Internet <URL: https://www.juniper.net/techpubs/en_US/junos15.1/topics/concept/ nsr-overview.html>

  The following analysis is given by the present invention.

  In order to realize high reliability of the centralized control type communication system described in Patent Documents 1 and 2, in addition to the centralized control server, the path control engine portion operating in cooperation with the centralized control server is made redundant. Also need to do.

Here, a method for realizing redundancy of the route control engine will be described. There are two types of methods for realizing the redundancy of the route control engine: a method using the Graceful Restart procedure of Non-Patent Documents 4 and 5, and an internal state synchronization method. The Graceful Restart procedure disclosed in Non-Patent Documents 6 and 7 is a procedure used when restarting only the control unit in the router (Non-Patent Document 3) that originally separated the control unit and the transfer unit. . When the control unit is restarted, the path control protocol processing unit operating on the control unit needs to restore the internal state that had been held before the restart. The internal state is restored from a router adjacent to the router that is to be restarted. The specific procedure of Graceful Restart is as follows.
1. The route control protocol unit notifies the adjacent router to perform the restart.
2. The neighboring router that has received the notification continues the transfer operation even if there is no response in the routing protocol from the router.
3. The route control protocol unit that has been restarted restores the internal state by acquiring information from the adjacent router.

In the routing engine redundancy method using the Graceful Restart procedure, the routing engine performs the following operation.
1. The standby route control engine that detects a failure of the active route control engine sends a restart notification in the Graceful Restart procedure to the adjacent router.
2. Thereafter, the standby route control engine restores the internal state by acquiring information from the adjacent router by the Graceful Restart procedure.

  In the internal state synchronization method disclosed in Non-Patent Document 1 and Non-Patent Document 2, which is another redundancy method, the internal states in the active and standby route control engines are always synchronized. If a message that changes the internal state is received, the routing engines of both systems update their internal state. As a result, even when a failure occurs in the active system, the standby system can immediately take over the operation.

  However, the methods based on the Graceful Restart procedure in Non-Patent Documents 4 and 5 require the support of neighboring routers, and there is a problem that they cannot be handled in cases where the neighboring routers do not support them. Even in a configuration in which the central control server and the route control engine operate in cooperation, it is possible that an adjacent router does not support the Graceful Restart procedure.

  Also, the internal state synchronization method, as the name suggests, requires synchronization of the internal state. When a routing message with an internal state update is received, the routing engines of both systems need to send a response message after confirming that the internal state has been updated. There is a problem. As a result, it takes a long time to exchange messages with neighboring routers. In addition, it is necessary to incorporate a mechanism for performing synchronization with an existing route control engine, and there is a problem that the degree of difficulty in mounting is high.

  It is an object of the present invention to provide a control device, a communication system, a communication method, and a program that can contribute to facilitating the redundancy of a route control engine in a configuration in which a central control server and a route control engine operate in cooperation. To do.

  According to a first aspect, a routing protocol that is connected to a forwarding device that forwards a packet according to a forwarding rule, communicates with an adjacent router via the forwarding device using a predetermined routing protocol, and generates route information. A transfer rule setting unit that sets a transfer rule that causes the transfer device to perform a transfer operation corresponding to the route information based on the route information generated by the route control protocol processing unit, and There is provided a control device in which a plurality of route control protocol processing units are arranged, and each route control protocol processing unit is configured to be able to communicate with the adjacent router as different routers arranged on a logical network.

  According to a second aspect, there is provided a communication system including a transfer device that transfers a packet according to a transfer rule and the control device described above.

  According to a third aspect, a plurality of routes that are connected to a transfer device that transfers a packet according to a transfer rule, communicate with an adjacent router through the transfer device using a predetermined routing control protocol, and generate route information. A control protocol processing unit; and a transfer rule setting unit that sets a transfer rule that causes the transfer device to perform a transfer operation corresponding to the route information based on the route information generated by the route control protocol processing unit. The control device sets a transfer rule for the plurality of route control protocol processing units to communicate with the adjacent routers as different routers arranged on a logical network in the transfer device; and Setting a transfer rule for data transfer on the device based on the route information created by the route control protocol processing unit. The law is provided. The method is associated with a specific machine, a control device that sets transfer rules in the transfer device.

  According to a fourth aspect, a plurality of routes that are connected to a transfer device that transfers a packet in accordance with a transfer rule, communicate with an adjacent router using the predetermined route control protocol via the transfer device, and generate route information. A control protocol processing unit; and a transfer rule setting unit that sets a transfer rule that causes the transfer device to perform a transfer operation corresponding to the route information based on the route information generated by the route control protocol processing unit. A process for setting a transfer rule for the plurality of route control protocol processing units to communicate with the adjacent router as different routers arranged on a logical network in the transfer device in the computer constituting the control device And processing for setting a transfer rule for data transfer on the transfer device based on the route information created by the route control protocol processing unit With the program for the execution is provided. This program can be recorded on a computer-readable (non-transient) storage medium. That is, the present invention can be embodied as a computer program product.

  ADVANTAGE OF THE INVENTION According to this invention, in the structure which a centralized control server and a route control engine operate | move in cooperation, it becomes possible to contribute to the simplification of the redundancy of a route control engine.

It is a figure which shows the structure of one Embodiment of this invention. It is a figure for demonstrating operation | movement of one Embodiment of this invention. It is a figure for demonstrating operation | movement of one Embodiment of this invention. It is a figure for demonstrating operation | movement of one Embodiment of this invention. It is a figure for demonstrating operation | movement of one Embodiment of this invention. It is a figure which shows the structure of the communication system of the 1st Embodiment of this invention. It is a figure which shows the detailed structure of the controller part of the communication system of the 1st Embodiment of this invention. It is a figure which shows an example of the information hold | maintained in topology DB of the controller part of the communication system of the 1st Embodiment of this invention. It is a figure which shows an example of the information hold | maintained at interface corresponding | compatible DB of the controller part of the communication system of the 1st Embodiment of this invention. It is a figure which shows an example of the transfer rule for routing protocols set by the communication system of the 1st Embodiment of this invention. It is a flowchart showing the flow of the setting of the transfer rule for control by the communication system of the 1st Embodiment of this invention. It is the figure which imaged the logical router comprised by the route control protocol process part which operate | moves on the centralized control server of the 1st Embodiment of this invention. It is a sequence diagram showing the whole operation | movement of the communication system of the 1st Embodiment of this invention. It is a figure which shows the detailed structure of the controller part of the communication system of the 2nd Embodiment of this invention. It is a figure for demonstrating the update operation | movement of the transfer rule for data transfer according to the path | route information by the controller part of the communication system of the 2nd Embodiment of this invention. It is a figure for demonstrating the update operation | movement of the transfer rule for data transfer according to the path | route information by the controller part of the communication system of the 2nd Embodiment of this invention. It is a figure for demonstrating the update operation | movement of the transfer rule for data transfer according to the path | route information by the controller part of the communication system of the 2nd Embodiment of this invention.

  First, an outline of an embodiment of the present invention will be described with reference to the drawings. Note that the reference numerals of the drawings attached to this summary are attached to the respective elements for convenience as an example for facilitating understanding, and are not intended to limit the present invention to the illustrated embodiment.

  In the embodiment, as shown in FIG. 1, the present invention can be realized by a transfer device that transfers a packet according to a transfer rule and a connected control device 100. More specifically, the control device 100 communicates with an adjacent router using a predetermined route control protocol via the transfer device 200 to generate route information, and the route control protocol processing. A transfer rule setting unit that sets a transfer rule that causes the transfer apparatus 200 to perform a transfer operation corresponding to the route information based on the route information generated by the unit 101. A plurality of the route control protocol processing units 101 are arranged, and each route control protocol processing unit 101 is configured to be able to communicate with an adjacent router as different routers arranged on a logical network.

  Hereinafter, an example of the operation of the control device 100 will be described with reference to FIGS. First, as shown in FIG. 2, the transfer rule setting unit 102 of the control device 100 creates a transfer rule for transferring a message according to a predetermined route control protocol between the route control protocol processing unit 101 and an adjacent router, Set in the transfer device 200. As a result, each of the route control engines can be operated independently.

  Thereafter, as shown in FIG. 3, the route control protocol processing unit 101 and the adjacent router start communication using the route control protocol. In the example of FIG. 3, two route control protocol processing units 101 communicate with adjacent routers.

  As shown in FIG. 4, the route control protocol processing unit 101 creates route information using information obtained by communication with an adjacent router, and transmits the route information to the transfer rule setting unit 102. The transfer rule setting unit 102 creates a transfer rule for data transfer in the transfer device 200 based on the path information and sets it in the transfer device 200.

  Thereafter, as shown in FIG. 5, it is possible to perform data communication according to a transfer rule for data transfer. For example, the transfer device 200 refers to the transfer rule for data transfer and transfers the packet to the destination corresponding to the layer 3 address of the received packet.

  As described above, since a plurality of route control protocol processing units 101 are prepared, the redundancy of the route control engine is achieved. Even when a failure occurs in a part of the plurality of route control protocol processing units 101, route information is created by the normal route control protocol processing unit 101 and supplied to the transfer rule setting unit 102. Further, even when a failure occurs in the route control protocol processing unit 101, the Graceful Restart procedure is not necessary, and it is not necessary to synchronize the internal state between the route control protocol processing units 101. The reason is that a plurality of route control protocol processing units 101 employ a configuration in which route information is created by communicating with adjacent routers as independent routers.

[First Embodiment]
Next, a first embodiment of the present invention will be described in detail with reference to the drawings. FIG. 6 is a diagram showing a configuration of a communication system according to the first exemplary embodiment of the present invention. Referring to FIG. 6, a configuration in which the central control server 3 and the control target network 40 configured by the switches 21 to 25 are connected is illustrated. In the example of FIG. 6, the control target network 40 is configured by five switches, but the number of switches configuring the control target network 40 is not limited. In FIG. 6, “0x21” or the like shown in the lower row of the switch box indicates the switch ID. In the example of FIG. 6, routers connected to such a control target network 40 are shown as adjacent routers 12 to 15. Hereinafter, description will be made assuming that the adjacent routers 12 to 15 are connected to the switches 22 to 25, respectively. The switch 21 is connected to the control protocol processing unit 30/31 of the central control server 3 through a different interface.

  The switches 21 to 25 are open flow switches introduced in Non-Patent Document 1 and the like. The switches 21 to 25 hold transfer rules called flow entries, select a transfer rule having a matching condition that matches the received packet from the transfer rules, and transfer to a transfer destination determined by the transfer rule. Performs operations such as header rewriting.

  The centralized control server 3 includes control protocol processing units 30 and 31 and a controller unit 32 that operate independently of each other.

  The controller unit 32 of the centralized control server 3 corresponds to the control device described above, and controls the switches 21 to 25 by setting transfer rules for the switches 21 to 25 using the OpenFlow protocol. A broken line between the controller unit 32 and the switches 21 to 25 in FIG. 6 indicates a secure channel for exchanging control messages using the OpenFlow protocol. In the following embodiment, an open flow switch is used as the switches 21 to 25 and the controller unit 32 functions as an open flow controller. However, other centralized control architectures may be used.

  The transfer rule set in the switches 21 to 25 by the controller unit 32 of the centralized control server 3 includes a transfer rule for transferring a route control message between the control protocol processing units 30 and 31 and the adjacent routers 12 to 15 (control transfer rule). ) And a transfer rule for transferring user data of the control target network 40. The control transfer rules include a control unicast transfer rule for transferring by unicast and a control multicast transfer rule. These details will be described later.

  The control protocol processing units 30 and 31 transmit / receive a route control message to / from the adjacent routers 12 to 15 via the switches 21 to 25 controlled by the controller unit 32, and create route information. The created path information is provided to the controller unit 32 and used when creating a transfer rule for data transfer.

  Next, details of the controller unit 32 of the central control server 3 will be described. FIG. 7 is a diagram illustrating a detailed configuration of the controller unit of the communication system according to the first embodiment of this invention. Referring to FIG. 7, an interface correspondence database (DB) 321, a topology database (DB) 322, a control transfer path calculation unit 323, a control transfer tree calculation unit 324, and a control unicast transfer rule generation unit 325 And a control multicast transfer rule generating unit 326, a transfer rule sending unit 327, a plurality of data transfer rule generating units 3281 and 3282, a priority adjusting unit 329, and a secure channel 330. Has been.

  The topology DB 322 is a database that stores topology information of the control target network 40. The topology information can be created by a set of connection relationships between the switches 21 to 25 in the control target network 40. FIG. 8 is a diagram illustrating an example of information held in the topology DB 322. The example of FIG. 8 shows a configuration that can store an entry in which the port number of each switch identified by the switch ID, the ID of the opposite switch, and the port number are associated with each other. For example, the top entry in FIG. 8 indicates that port 9 of the switch with switch ID = 0x21 is connected to port 1 of the switch with switch ID = 0x22. This entry represents a link between the switch 21 and the switch 22 in FIG. Note that the topology information shown in FIG. 8 is merely an example, and is not limited to the form shown in FIG.

  The interface correspondence DB 321 is a database for managing the correspondence relationship between the adjacent routers 12 to 15 and the control protocol processing units 30 and 31 necessary for creating the control transfer rule. FIG. 9 is a diagram illustrating an example of information held in the interface correspondence DB 321. In the example of FIG. 9, in addition to the combination of the information of the switch connected to the adjacent router and the information of the adjacent router, the interface information of each of the control protocol control units 30 and 31 to which the information from the adjacent router should be transmitted is set. Has been.

  For example, the top entry in FIG. 9 is the port number 3 of the switch with the switch ID = 0x22, the MAC address XX: XX: XX: XX: XX: 01, and the protocol number of the IP address 192.168.0.1 = This indicates that there is a router operating in 89 (OSPF). In addition, the router transmits the MAC address XX: XX: XX: XX: XX: 02, the IP address 192.168.0.2, and the protocol number = 89 (OSPF) via the port 1 of the switch = 0x21. It is shown that it is connected to the control protocol processing unit 30 operating in (). Similarly, this router receives the MAC address XX: XX: XX: XX: XX: 03, the IP address 192.168.0.3, and the protocol number = 89 (via the port 5 of the switch = 0x21. It is shown that it is connected to a control protocol processing unit 31 operating in OSPF). That is, the top entry in FIG. 9 indicates that the adjacent router 12 in FIG. 6 and the control protocol processing units 30 and 31 should be connected to the switch 22 through the ports 1 and 5 of the switch 21. ing. Therefore, when the route control message transmitted from the adjacent router 12 is to be transmitted to the control protocol processing unit 30, the route from the port 3 of the switch 22 to the port 1 of the switch 21 is calculated, and the transfer along this is performed. The transfer rule for control and the switches 21 and 22 may be set. In FIG. 9, “*” represents a wild card. Thus, some items of the interface correspondence DB 321 can be excluded from the match condition.

  In the above description, the MAC address and IP address indicate Media Access Control address and Internet Protocol address, respectively. OSPF is an abbreviation for Open Shortest Path First.

  The information stored in the topology DB 322 and the interface correspondence DB 321 is not particularly limited in the form of collection. For example, the topology information stored in the topology DB 322 can be collected using a topology detection method such as Link Layer Discovery Protocol (LLDP), or can be set based on network information by a network administrator.

  The control transfer path calculation unit 323 calculates a path between switches indicated by the interface correspondence DB 321 based on the topology DB 322. For example, the control transfer path calculation unit 323 calculates a path between the switch having the switch ID = 0x22 and the switch having the switch ID = 0x21 based on the top entry in FIG. The control transfer path calculation unit 323 sends the calculated path to the control unicast transfer rule generation unit 325.

  The control unicast transfer rule generation unit 325 causes a switch on the path calculated by the control transfer path calculation unit 323 to transfer a route control message along the path (control unicast transfer control). Transfer rule). The control unicast transfer rule generation unit 325 sends the generated control transfer rule to the transfer rule transmission unit 327.

  In this embodiment, as shown in FIG. 6, there are two control protocol processing units, and it is necessary to set a transfer rule in the switch so that the multicast packet reaches the control protocol processing units 30 and 31. . The control forwarding tree calculation unit 324 calculates a shortest path tree for this control multicast as a forwarding tree. For example, based on the top entry in FIG. 9, the control transfer tree calculation unit 324 uses the switch with the switch ID = 0x22 as the root, and transfers to the port 1 with the switch ID = 0x21 and the port 5 Calculate the tree. Further, the control transfer tree calculation unit 324 calculates two transfer trees starting from the control protocol processing units 30 and 31, respectively. The control transfer tree calculation unit 324 sends these calculated transfer trees to the control multicast transfer rule generation unit 326.

  The control multicast forwarding rule generation unit 326 causes the switch on the forwarding tree calculated by the control forwarding tree calculation unit 324 to forward the routing message along the forwarding tree (control multicast forwarding). Rule). The control unicast transfer rule generation unit 325 sends the generated control transfer rule to the transfer rule transmission unit 327.

  Here, the match condition to be set in the control multicast transfer rule will be described. The IP address of the multicast packet may vary depending on the application, but basically the destination IP address is the same for all packets sent from any end point (224.0.0.5 or 224.0.0.6 in the case of OSPF). ). For this reason, in the case of matching only with the destination IP address, it may happen that it cannot be delivered to an appropriate destination (there may be a return to the transmission source). Therefore, in this embodiment, a transfer rule including the transmission source IP address in the match condition is created. In this way, packets from each transmission source can be distinguished and transferred. For example, when the IP address of the adjacent router 12 in FIG. 6 is 192.168.0.1 (see the entry of the switch 0x22 in FIG. 9), “destination 224.0.0.5/32, transmission source 192.168 .. A transfer rule is created so that the 0.1 / 32 ″ packet is delivered to the interfaces of the control protocol processing units 30 and 31 (port 1 and port 5 of the switch 0x21). Similarly, when the transmission source is the control protocol processing unit 30 or the control protocol processing unit 31, a transfer rule is created.

  In the above example, the transfer rule is created when the destination IP address is 224.0.0.5. However, it is assumed that the destination IP address is 224.0.0.6. It is necessary to put three sets. However, the destination IP address of the match condition may be “224.0.0.0/4”, the source IP address may be “192.168.0.1/32”, and the protocol number may be “89”. In this way, the destination IP address can cover both 224.0.0.5 and 224.0.0.6, and the number of transfer rules can be reduced.

  Data transfer rule generation units 3281 and 3282 are provided in association with the control protocol processing units 30 and 31, receive path information from the respective control protocol processing units, and generate data transfer transfer rules (data transfer rules). Generate. The data transfer rule generation units 3281 and 3282 determine priorities for the generated data transfer rules. Here, the priority is used as a priority referenced by the switch when the switch receives the packet. For example, when there are two or more transfer rules that match the received packet, the switch uses the transfer rule with the higher priority to transfer the packet. The data transfer rule generation units 3281 and 3282 send the generated transfer rules to the priority adjustment unit 329 and receive confirmation, and then send the data transfer rules to the transfer rule transmission unit 327. In FIG. 7, the connection lines between the data transfer rule generation units 3281 and 3282 and the topology DB 322 and the interface correspondence DB 321 are omitted. However, the data transfer rule generation units 3281 and 3282 refer to these DBs. Generate forwarding rules. Specifically, the data transfer rule generation units 3281 and 3282 identify the connection port with the switch corresponding to the next hop indicated in the path information received from the control protocol processing units 30 and 31 from the interface correspondence DB 321. Then, the data transfer rule generation units 3281 and 3282 refer to the topology DB 322, calculate a route, and create a data transfer rule to be set in the switch on the route.

  FIG. 10 is an example of the control unicast transfer rule set by the switch 22 (ID = 0x22) by the data transfer rule generation units 3281 and 3282. For example, as shown in the upper part of FIG. 10, it is assumed that the route information with the prefix: 172.16.0.0/24 and the next hop: the adjacent router 13 is obtained from the control protocol processing units 30 and 31. . In this case, the data transfer rule generation units 3281 and 3282 create a transfer route that outputs a packet having a destination IP address of 172.16.0.0/24 to the adjacent router 13 as a match condition. Since the adjacent routers with which the routing control message is exchanged are the same, the routing information received by the data transfer rule generation units 3281 and 3282 from the control protocol processing units 30 and 31 is also the same. The transfer rules created by the rule generation units 3281 and 3282 are also the same. In this embodiment, for management, the MAC address assigned to the control protocol processing units 30 and 31 is set in the destination MAC address field in the match condition, and then masked (that is, a wild card). ). By doing so, the relationship between the control protocol processing unit and the transfer rule made based on the information becomes clear. For example, when certain route information is canceled, it is easy to identify and delete the corresponding transfer rule.

  In the above example, the destination MAC address in the match condition is used to distinguish between the control protocol processing unit and the transfer rule based on the information. However, in the other fields, the transfer rule Information for identifying the control protocol processing unit that provides the route information used for creation may be stored. Also, if it is not necessary to distinguish between transfer rules in the management as described above, as shown in FIG. 10, when the same transfer rule exists without setting two transfer rules, the transfer sent later The rule may be discarded.

  The priority adjustment unit 329 confirms the priority set by the data transfer rule generation units 3281 and 3282 for the data transfer rule. Then, the priority adjustment unit 329 gives the transfer rule sending unit 327 a priority higher than the priority set by the data transfer rule generation units 3281 and 3282 for the data transfer rule as the priority of the control transfer rule. Notice. For example, the priority determined by the data transfer rule generation units 3281 and 3282 with respect to the data transfer rule is higher as the numerical value is higher. For example, it is assumed that the priority is in a range of 10000 to 12000. In this case, the priority adjustment unit 329 notifies the transfer rule transmission unit 327 to set a priority (for example, 15000) higher than the priority range.

  The transfer rule sending unit 327 sets the switch corresponding to the transfer rule generated by the control unicast transfer rule generation unit 325, the control multicast transfer rule generation unit 326, and the data transfer rule generation units 3281 and 3282. At this time, the transfer rule transmission unit 327 transmits the priority notified from the priority adjustment unit 329 to the switch together with the control transfer rule. In this way, reachability of the route control message between the control protocol processing units 30 and 31 and the adjacent routers 12 to 15 is ensured.

  Note that each unit (processing unit) of the communication system and the centralized control server shown in FIGS. 6 and 7 is a computer program that causes a computer configuring these devices C1 to execute the above-described processes using the hardware. Can also be realized.

  Next, the operation of this embodiment will be described in detail with reference to the drawings. FIG. 11 is a flowchart showing a flow of setting a control unicast transfer rule by the communication system according to the first embodiment of this invention. Referring to FIG. 11, first, the controller unit 32 selects one entry indicating an end point from the interface correspondence DB 321 and calculates a route (step S001).

  Next, the controller unit 32 creates a transfer rule for a route control protocol message using the calculated route (step S002).

  Next, the controller unit 32 adjusts the priority so that a higher priority than the data transfer rule is set for the created routing control protocol message transfer rule (step S003).

  Next, the controller unit 32 sets a transfer rule for a route control protocol message together with the priority for the switch on the route (step S004).

  The controller unit 32 performs the above processing for all entries in the interface correspondence DB 321. Note that the control multicast transfer rule is different only in that the route of step S001 in FIG. 11 becomes a transfer tree, and can be set in the same procedure.

  As a result, the routing protocol message can be exchanged between the adjacent routers 12 to 15 and the control protocol processing units 30 and 31. When viewed from the adjacent routers 12 to 15, the control protocol processing units 30 and 31 are recognized as routers existing in each control target network as indicated by reference numerals 41 and 42 in FIG. 12. 12 indicate logical connection relationships between the adjacent routers 12 to 15 and the control protocol processing unit 30 realized by the control unicast transfer rule.

  FIG. 13 is a sequence diagram showing the overall operation of the communication system after the setting of the control transfer rule as described above is completed. As illustrated in FIG. 13, the control protocol processing units 30 and 31 communicate independently with neighboring routers (steps S <b> 101-1 and S <b> 101-2).

  Then, the control protocol processing units 30 and 31 update the internal routing table based on the result of communication with the adjacent router, and transmit the changed routing table entry to the controller unit 32 as routing information (step). S102-1, S102-2).

  The controller unit 32 creates the data transfer rule illustrated in FIG. 10 based on the route information received from the control protocol processing units 30 and 31 (step S103), and creates the created data transfer rule on the switch on the route. Is set (step S104).

  As is clear from the above description, according to the present embodiment, even if a failure occurs in any one of the control protocol processing units 30 and 31, route information is provided from one control protocol processing unit, and the controller unit 32 can continue the control of the control target network 40. Further, in adopting such a redundant configuration, there is no restriction that the adjacent router must support the Graceful Restart procedure and the internal state synchronization method.

[Second Embodiment]
Next, a description will be given of a second embodiment in which a change is made to the controller unit 32 of the first embodiment so that the transfer rule to be set is kept consistent. Since the basic configuration and operation are the same as those in the first embodiment, differences from the first embodiment will be mainly described below.

  FIG. 14 is a diagram illustrating a detailed configuration of the controller unit 32a of the communication system according to the second embodiment of this invention. The interface correspondence database (DB) 321, topology database (DB) 322, control transfer path calculation unit 323, control transfer tree calculation unit 324, control unicast transfer rule generation unit 325, control multicast transfer on the right side of FIG. The configurations of the rule generation unit 326 and the transfer rule transmission unit 327 are the same as those in the first embodiment.

  The controller unit 32a includes a route information receiving unit 3331 and 3332 for receiving route information from the control protocol processing units 30 and 31, respectively, and a route information database (DB), instead of having only one data transfer rule generating unit 328. ) 3321 and 3322 are arranged in plural.

  In this embodiment, the route information receiving units 3331 and 3332 arranged in association with the control protocol processing units 30 and 31 receive the route information from the control protocol processing units 30 and 31 and store them in the route information DBs 3321 and 3322.

The data transfer rule generation unit 328 extracts the route information from the route information DBs 3321 and 3322 at a predetermined timing, and creates a transfer rule according to the following rules while comparing the two.
(1) When the route information of a certain destination IP address exists in one or both of the route information DBs (if they exist in both, the next hop information of both is the same, that is, both are the same next transfer destination If indicated)
In this case, the data transfer rule generation unit 328 inquires of the switch to which the transfer rule is to be set whether or not the corresponding transfer rule has been set, and if not set, sets the created transfer rule (see FIG. 15).
(2) When route information of a certain destination IP address does not exist in any route information DB In this case, the data transfer rule generation unit 328 sets the corresponding transfer rule in the switch to which the transfer rule is set. Inquires whether or not the transfer rule has been set, and if the corresponding transfer rule has been set, the deletion is instructed (see FIG. 16).
(3) When the route information of a certain destination IP address exists in both route information DBs, but their next hop information (next transfer destination) is different. In this case, the data transfer rule generation unit 328 Check the update time and create a data transfer rule based on the later route information. At that time, the data transfer rule generation unit 328 confirms whether or not the transfer rule for the same destination IP address has already been set in the switch for which the transfer rule is to be set, and if it exists, the update must exist. Make new settings.

  As described above, in this embodiment, the data transfer rule generation unit 328 creates a transfer rule while confirming the consistency between the path information received from the control protocol processing units 30 and 31. For this reason, it is possible to reduce the number of transfer rules set in the switch. Further, as shown in the operation (3) above, even when there is a mismatch between the route information, the transfer rule can be created with priority on the latest route information. For this reason, there is an advantage that it is possible to quickly cope with a failure of an adjacent router.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and further modifications, substitutions, and adjustments are possible without departing from the basic technical idea of the present invention. Can be added. For example, the network configuration, the configuration of each element, and the expression form of a message shown in each drawing are examples for helping understanding of the present invention, and are not limited to the configuration shown in these drawings.

  For example, in the above-described embodiment, two control protocol processing units 30 and 31 are prepared and redundant. However, three or more control protocol processing units 30 and 31 may be prepared. In the above-described embodiment, the control protocol processing units 30 and 31 are arranged in the central control server 3, but the control protocol processing units 30 and 31 may be arranged in another server or the like. Moreover, it is also possible to employ a configuration in which the control protocol processing units 30 and 31 and the controller unit 32 operate on a virtual server using a virtualization technique.

  Further, in the above-described embodiment, the control transfer rule generation unit is described as being provided in parallel for the unicast and the multicast in the controller unit 32. Since they are common in creating a transfer rule that realizes a route, they may be integrated.

Finally, a preferred form of the invention is summarized.
[First embodiment]
(Refer to the control device according to the first viewpoint)
[Second form]
In the control device of the first form,
A control device in which a plurality of the transfer rule setting units are provided in association with the route control protocol processing unit.
[Third embodiment]
In the control device of the first or second form,
The transfer rule setting unit is a control device that adds information for identifying the route control protocol processing unit to a predetermined field of the transfer rule.
[Fourth form]
In the control device of the third aspect,
A control device that uses a MAC address assigned to a route control protocol processing unit as information for identifying the route control protocol processing unit.
[Fifth embodiment]
In the control device according to any one of the first to fourth aspects,
A control provided with a transfer rule setting unit for control, which sets a transfer rule for realizing communication by the route control protocol between the route control protocol processing unit and the adjacent router and between the route control protocol processing units in the transfer device. apparatus.
[Sixth embodiment]
In the control device of the fifth aspect,
The control transfer rule setting unit is a control device that sets a transfer rule that uses a source address as a match condition for multicast communication among communication using the route control protocol.
[Seventh form]
In the control device according to any one of the first to sixth aspects,
Furthermore, a path information storage unit that stores path information received from the plurality of path control protocol processing units, respectively,
The transfer rule setting unit is a control device that extracts route information from the route information storage unit and sets a transfer rule in a target transfer device.
[Eighth form]
In the control device according to any one of the first to sixth aspects,
Furthermore, a path information storage unit that stores path information received from the plurality of path control protocol processing units, respectively,
The transfer rule setting unit is a control device that deletes a transfer rule corresponding to the route information from a target transfer device when route information of a specific destination no longer exists from the route information storage unit.
[Ninth Embodiment]
In the control device according to any one of the first to sixth aspects,
Furthermore, a path information storage unit that stores path information received from the plurality of path control protocol processing units, respectively,
The transfer rule setting unit, when the transfer destination indicated in the route information received from the plurality of route control protocol processing units is different, the transfer set to the target transfer device based on the route information with the later update time A control unit that creates rules.
[Tenth embodiment]
(Refer to the communication system according to the second viewpoint)
[Eleventh form]
(Refer to the communication method according to the third viewpoint)
[Twelfth embodiment]
(Refer to the computer program according to the fourth aspect above)
The tenth to twelfth aspects can be expanded to the second to ninth aspects, similarly to the first aspect.

  Each disclosure of the above-mentioned patent document and non-patent document is incorporated herein by reference. Within the scope of the entire disclosure (including claims) of the present invention, the embodiments and examples can be changed and adjusted based on the basic technical concept. Various combinations or selections of various disclosed elements (including each element of each claim, each element of each embodiment or example, each element of each drawing, etc.) are possible within the scope of the disclosure of the present invention. It is. That is, the present invention of course includes various variations and modifications that could be made by those skilled in the art according to the entire disclosure including the claims and the technical idea. In particular, with respect to the numerical ranges described in this document, any numerical value or small range included in the range should be construed as being specifically described even if there is no specific description.

3 Centralized control server 12-15 Adjacent router 21-25 Switch 30, 31 Control protocol processing part 32, 32a Controller part 32 Transfer rule sending part 40 Control object network 41, 42 Logical router 51-54 Logical link 100 Control apparatus 101 Path control Protocol processing unit 102 Transfer rule setting unit 200 Transfer device 321 DB for interface
322 Topology DB
323 Control transfer path calculation unit 324 Control transfer tree calculation unit 325 Control unicast transfer rule generation unit 326 Control multicast transfer rule generation unit 327 Transfer rule transmission unit 328, 3281, 3282 Data transfer rule generation unit 329 Priority Adjustment unit 330 Secure channel 3331, 3332 Route information receiving unit 3321, 3322 Route information DB

Claims (12)

Connected to a forwarding device that forwards packets according to forwarding rules,
A route control protocol processing unit for generating route information by communicating with an adjacent router using a predetermined route control protocol via the transfer device;
A transfer rule setting unit that sets a transfer rule that causes the transfer device to perform a transfer operation corresponding to the route information based on the route information generated by the route control protocol processing unit;
A plurality of the routing control protocol processing units are arranged,
Each routing control protocol processing unit is configured to be able to communicate with the adjacent router as a different router disposed on a logical network;
A control device characterized by.   The control device according to claim 1, wherein a plurality of transfer rule setting units are provided in association with the route control protocol processing unit.   The control device according to claim 2, wherein the transfer rule setting unit adds information for identifying the route control protocol processing unit to a predetermined field of the transfer rule.   The control device according to claim 2, wherein the information for identifying the route control protocol processing unit is a MAC address assigned to the route control protocol processing unit.   A control transfer rule setting unit configured to set a transfer rule for realizing communication by the route control protocol between the route control protocol processing unit and the adjacent router and between the route control protocol processing units in the transfer device. Item 5. The control device according to any one of Items 1 to 4.   The control device according to claim 5, wherein the control transfer rule setting unit sets a transfer rule using a transmission source address as a match condition for multicast communication among communication using the route control protocol. Furthermore, a path information storage unit that stores path information received from the plurality of path control protocol processing units, respectively,
The control device according to claim 1, wherein the transfer rule setting unit extracts route information from the route information storage unit and sets the transfer rule. Furthermore, a path information storage unit that stores path information received from the plurality of path control protocol processing units, respectively,
The control device according to any one of claims 1 to 6, wherein the transfer rule setting unit deletes a transfer rule corresponding to the route information when there is no route information of a specific destination from the route information storage unit. Furthermore, a path information storage unit that stores path information received from the plurality of path control protocol processing units, respectively,
The transfer rule setting unit creates the transfer rule based on route information with a later update time when the transfer destination indicated in the route information received from the plurality of route control protocol processing units is different. The control device according to any one of 1 to 6. A transfer device for transferring packets in accordance with transfer rules;
Connected to the transfer device;
A route control protocol processing unit for generating route information by communicating with an adjacent router using a predetermined route control protocol via the transfer device;
A transfer rule setting unit that sets a transfer rule that causes the transfer device to perform a transfer operation corresponding to the route information based on the route information generated by the route control protocol processing unit;
A plurality of the routing control protocol processing units are arranged,
Each routing control protocol processing unit is configured to be able to communicate with the adjacent routers as different routers arranged on a logical network;
A communication system including: Connected to a forwarding device that forwards packets according to forwarding rules,
A plurality of routing protocol processing units that communicate with neighboring routers via a predetermined routing protocol via the transfer device and generate routing information;
A control device comprising: a transfer rule setting unit that sets a transfer rule that causes the transfer device to perform a transfer operation corresponding to the route information based on the route information generated by the route control protocol processing unit;
Setting a transfer rule for the plurality of routing protocol processing units to communicate with the adjacent routers as different routers arranged on a logical network in the transfer device;
Setting a transfer rule for data transfer in the transfer device based on the route information created by the route control protocol processing unit. Connected to a forwarding device that forwards packets according to forwarding rules,
A plurality of routing protocol processing units that communicate with neighboring routers via a predetermined routing protocol via the transfer device and generate routing information;
And a transfer rule setting unit configured to set a transfer rule for causing the transfer device to perform a transfer operation corresponding to the route information based on the route information generated by the route control protocol processing unit. On the computer,
A process for setting a transfer rule for the plurality of route control protocol processing units to communicate with the adjacent routers as different routers arranged on a logical network in the transfer device;
A process for setting a transfer rule for data transfer on the transfer device based on the route information created by the route control protocol processing unit;
A program that executes

Images