JP6490640B2 - Communication device and delivery table synchronization method - Google Patents

Description

  The present disclosure relates to a data synchronization method between devices in a network system that realizes both device redundancy and path redundancy.

  Network systems using layer 2 technology in the OSI reference model represented by Ethernet (registered trademark) technology are widely used. In the network system, there is a LAG (Link Aggregation Group) technique as a technique for realizing improvement in reliability and capacity expansion. In this method, apparatuses are connected by a plurality of physical links, and frame transfer is realized by using a plurality of physical links as one logical link.

  LAG can be improved in reliability and capacity can be expanded by a simple method, and is standardized in IEEE. However, LAG can realize a path redundancy function, but cannot realize a device redundancy function. Therefore, a multi-chassis LAG (MC-LAG) function has been proposed to provide a device redundancy function (Non-Patent Document 1).

  The multi-chassis LAG function operates a plurality of communication devices virtually as one communication device. The opposing device can be connected to a communication device group virtually regarded as one communication device using the LAG function. In other words, it is possible to use the counter device equipped with the standard technology without any change, and it is possible to easily introduce a device redundant configuration.

  Traffic from the opposite device to the communication device group constituting the multi-chassis LAG is transmitted in accordance with the LAG data distribution rule of the opposite device. When route redundancy technology using the LAG function is used, traffic transmitted from the opposite device is physically received by one device, so transmission according to the transfer information of the device that received the frame is possible. there were. On the other hand, when the multi-chassis LAG function is used, it is necessary to share transfer information between apparatuses because a plurality of communication apparatuses are physically operated as one unit.

  Usually, communication devices constituting a multi-chassis LAG are directly connected by an inter-chassis line that connects the communication devices to each other. The inter-chassis line is used for exchange of failure occurrence status in multi-chassis LAG, transmission / reception of management frames including exchange of setting information, and transfer of traffic transmitted from the opposite device.

  However, when a failure occurs in the inter-chassis line, or when a failure occurs in a communication device constituting the multi-chassis LAG, transfer information is shared and synchronized between the communication devices constituting the multi-chassis LAG. It becomes impossible. For this reason, after recovering from the failure, it is necessary to share the update difference regarding the setting information generated during the failure occurrence period between the communication devices constituting the multichassis LAG, and to perform the synchronization process.

  For example, consider a case in which an MLDv2 (Multicast Listener Discovery version 2) function for efficiently performing multicast distribution is operated in a network system using a plurality of communication devices constituting a multi-chassis LAG. Hereinafter, description will be made assuming that multicast distribution based on MLDv2 is realized in a network system using a plurality of communication devices constituting a multichassis LAG. However, the contents described below are not limited to a specific technique or protocol such as MLDv2. The same discussion can be made if each of the communication devices constituting the multi-chassis LAG individually holds the setting information and synchronizes the setting information.

  MLDv2 dynamically changes the setting information related to the port of the communication device based on transmission / reception of a multicast distribution management frame. For example, when a multicast distribution start frame is received at a port of the communication apparatus, multicast distribution from the port is started, and when a multicast distribution stop frame is received, multicast distribution from the port is stopped. In this way, unnecessary multicast distribution can be suppressed, and the line utilization efficiency of the entire network system can be improved.

100G Ethernet Switch for Telecommunications Carriers Hitachi Metals Technical Report Vol. 31 (http://www.hitachi-metals.co.jp/rad/pdf/2015/vol31_s15.pdf, searched on May 12, 2016)

  As a method for realizing MLDv2 multicast distribution among a plurality of communication devices constituting a multi-chassis LAG, when any communication device of the communication device group constituting the multi-chassis LAG receives a multicast distribution management frame, the communication device group There is a method of transferring a multicast distribution management frame to another communication apparatus constituting the multi-chassis LAG using an inter-chassis line. This makes it possible to share distribution management information among all the communication devices constituting the multi-chassis LAG when there is no failure in the inter-chassis line or the communication device constituting the multi-chassis LAG. The distribution management table can be synchronized, but the distribution information cannot be shared when a failure has occurred in the inter-chassis line or the communication device constituting the multi-chassis LAG.

  For example, as shown in FIG. 1, a network comprising communication devices (SW1, SW2) constituting a multi-chassis LAG, opposing devices (3-7) connected to the respective communication devices through different physical lines, and an inter-chassis line 8 Think of a system. The communication device SWx (x is 1 or 2) is a port x1 connected to the opposite device 3 that performs multicast distribution, ports x2 to x5 that connect the opposite devices (4 to 7) that perform multicast reception, and an inter-chassis line 8, a port x 6 connected to a device that forms a set of multi-chassis LAGs via 8, and a distribution table x 7 that holds distribution information based on a multicast distribution management frame. The opposing devices (3 to 7) each have two ports (y1, y2) (y is an integer from 3 to 7), and are physically connected to the communication devices (SW1, SW2), respectively. Connect to a different line. Further, the opposing devices (3 to 7) configure the two physical lines of the ports (y1, y2) as LAGs, and transmit and receive frames logically as one line.

  In a state where no failure has occurred, when one communication device (for example, SW1) constituting the multichassis LAG receives a multicast distribution management frame, the opposite device (FIG. 1) responsible for the function of multicast distribution is received. In this example, the data is transferred to the opposite device 3) and transferred to the other communication device (for example, SW2) via the port (for example, port 16) connected to the device forming the set of the multi-chassis LAG and the inter-chassis line 8. By doing so, it is possible to share the distribution information.

  However, when a failure occurs in the inter-chassis line 8, the distribution table information cannot be shared by such a method. When a failure occurs in the inter-chassis line 8, for example, a method in which the communication device SW1 and the communication device SW2 operate as separate communication devices can be considered. That is, settings related to multicast distribution are managed independently by each communication device.

  By adopting such a method, when the multicast distribution management frame and the communication device handling the multicast distribution data are the same, the multicast distribution based on the setting by the multicast distribution management frame transmitted / received after the failure occurs is continued. On the other hand, when the multicast distribution management frame and the communication device that handles the multicast distribution data are different, the multicast distribution is continued based on the information of the multicast distribution table shared before the occurrence of the failure.

  By adopting such a method, although there is a possibility that the setting regarding the multicast distribution management frame transmitted / received after the occurrence of the failure may not be reflected, it is possible to continue the multicast distribution.

This will be described with reference to FIGS. 2 and 3. It is assumed that a failure has occurred in the inter-chassis line 8 in a state where a distribution table x7 for distributing multicast data to the opposing device 4 and the opposing device 5 is shared between the communication devices (SW1, SW2).
After that, during the failure occurrence period,
(1) The opposite device 4 transmits a multicast distribution stop frame from the port 41 to the port 12 of the communication device SW1,
(2) The opposite device 5 transmits a multicast distribution stop frame from the port 52 to the port 23 of the communication device SW2,
(3) The opposite device 6 transmits a multicast distribution start frame from the port 61 to the port 14 of the communication device SW1,
(4) The opposite device 7 transmits a multicast distribution start frame from the port 72 to the port 25 of the communication device SW2,
Let's think about the behavior of the case.

  FIG. 3 shows the distribution table state of communication device SW1 and communication device SW2 after transmission / reception of the multicast distribution stop frame and the multicast distribution start frame is completed, and multicast distribution information based on the distribution table. 2 and 3, the state of the distribution table after the transmission / reception of the multicast distribution stop frame and the multicast distribution start frame is completed is described in the column “at the time of failure recovery”.

  If there is no failure, the distribution management frame is shared between the communication device communication device SW1 and the communication device SW2, the description of the distribution table is corrected, and the state for the opposite device 4 and the opposite device 5 Is “undelivered”, and the statuses of the opposing device 6 and the opposing device 7 are synchronized with “delivered”.

  However, since a failure has occurred in the inter-chassis line, the distribution management frame is not shared between the communication device communication device SW1 and the communication device SW2, and the communication device SW1 and the communication device SW2 cannot synchronize the distribution table information. For this reason, after recovering from the failure occurrence state, the distribution table is repaired (synchronized) between the communication devices constituting the multichassis LAG.

However, the synchronization of the distribution table after the failure recovery is after a certain time has elapsed, and the following problems will occur until the synchronization is completed.
In the example of FIG. 3, it is assumed that all multicast distribution data is transmitted from the port 31 of the opposite apparatus 3. In the case of this example, distribution to the opposite device 7 becomes a problem.

  The multicast distribution data for the opposite device 4 is in a distribution state when a failure occurs, and the distribution is stopped when the multicast distribution stop frame (1) is received. That is, the state of the port 12 of the distribution table 17 changes from “distributed” to “not yet distributed” during the failure period by the frame (1). This is an operation expected in MLDv2. On the other hand, the multicast distribution stop frame is not shared by the communication device SW2 due to the failure of the inter-chassis line. For this reason, the state of the port 22 in the distribution table 27 remains “distribution”. However, since the multicast distribution data is transmitted from the opposite apparatus 3 to the communication apparatus SW1, the communication apparatus SW1 can stop the multicast distribution data by the multicast distribution stop frame.

  The multicast distribution data for the opposite device 5 is in a distribution state when a failure occurs, and it is expected that the communication device SW2 will stop distribution when the communication device SW2 receives the multicast distribution stop frame (2) in the failure state. However, the multicast distribution stop information is not shared by the communication device SW1 due to the failure of the inter-chassis line. That is, the state of the port 23 of the distribution table 27 changes from “distributed” to “not yet distributed” during the failure period due to the frame (2), but the state of the port 13 of the distribution table 17 remains “distributed”. . As a result, since the multicast distribution data is transmitted from the opposite device 3 to the communication device SW1, the communication device SW1 cannot stop the multicast distribution data, and there is unnecessary bandwidth occupation between the port 13 and the port 51 due to the multicast distribution data. Arise. However, since multicast data is discarded in the opposite apparatus 5, the influence on multicast distribution is small.

  The multicast distribution data for the opposite apparatus 6 is in an undistributed state when a failure occurs, and distribution is started when the multicast distribution start frame (3) is received. That is, the state of the port 14 of the distribution table 17 is changed from “undistributed” to “distributed” during the failure period by the frame (3). This is an operation expected in MLDv2. On the other hand, the multicast distribution start frame is not shared by the communication device SW2 due to the failure of the inter-chassis line. For this reason, the state of the port 24 of the distribution table 27 remains “undistributed”. However, since the multicast distribution data is transmitted from the opposite device 3 to the communication device SW1, the communication device SW1 can distribute the multicast distribution data by the multicast distribution start frame.

  The multicast distribution data for the opposite device 7 is in an undelivered state when a failure occurs, and it is expected that the communication device SW2 starts distribution when the communication device SW2 receives the multicast distribution start frame (4) in the failure state. However, the multicast distribution start information is not shared by the communication device SW1 due to the failure of the inter-chassis line. That is, the state of the port 25 of the distribution table 27 changes from “undelivered” to “distributed” during the failure period by the frame (4), but the state of the port 15 of the distribution table 17 remains “undistributed”. Yes, the communication device SW1 cannot reflect the setting for starting distribution from the port 15 to the port 71 of the opposite device 7. As a result, since the multicast distribution data is transmitted from the opposite device 3 to the communication device SW1, the multicast distribution data is not actually distributed even though the multicast distribution start frame is transmitted from the opposite device 7, and the multicast distribution data is transmitted. The influence on distribution is large (“A” in FIG. 3).

  For this reason, when recovering from a failure, it is necessary to repair the distribution table by synchronizing the distribution table information. In particular, as in the distribution information for the opposite device 7 in the example of FIG. 3, information that one of the devices constituting the multichassis LAG transitions from the non-delivery state to the distribution state during the failure occurrence period is It is necessary to perform distribution table management that synchronizes with

  In order to correctly restore the distribution tables of the communication device SW1 and the communication device SW2, for example, the change history of the distribution table is held, and the change history is matched between the communication device communication device SW1 and the communication device SW2, thereby ensuring consistency. There is a method of judging and making a transition to a correct distribution table state. However, if the distribution table is updated frequently during the time when the failure occurrence state continues, or if the failure occurrence state duration is very long, the change history may become very large. In addition, there is a problem that it takes a long time to recover the synchronization table. Furthermore, there is a possibility that the change history cannot be held.

  On the other hand, MLDv2 stipulates that a multicast distribution management frame is periodically transmitted and received in order to confirm the distribution state with respect to the opposite apparatus. For this reason, a fixed time elapses after recovery from the failure state by repairing the distribution table based on transmission / reception of the periodic multicast distribution management frame and notifying the other device that constitutes the multichassis LAG of the repair information. It is possible to restore the distribution table information possessed by all the communication devices constituting the multi-chassis LAG later. However, in other words, it is suggested that the inconsistency state of the distribution table may continue until a certain time elapses.

In other words, the conventional multi-chassis LAG has a problem that it takes time to synchronize the multicast distribution table of each communication apparatus after the failure recovery, and the start of the requested multicast distribution is delayed. was there.
Therefore, in order to solve the above-described problem, the present invention solves the problem of multicast when recovering from a failure of an inter-chassis line connecting between communication devices constituting the multi-chassis LAG or a failure of one communication device constituting the multi-chassis LAG. It is an object of the present invention to provide a communication device and a distribution table synchronization method that can synchronize distribution tables at an early stage.

  In order to solve the above-described problems, the present invention is configured such that when the network system constituting the multi-chassis LAG recovers from a failure state, all the differences in the distribution tables of the respective communication devices are synchronized. .

Specifically, a communication device according to the present invention is a communication device that constitutes a multi-chassis LAG (Link Aggregation Group),
Based on the multicast distribution management frame, a distribution table that stores distribution information in which “distribution” or “undistribution” of multicast data is set for each receiving device;
Matching the distribution information held in the distribution table with the distribution information held in the distribution table of another communication device for each receiving device, if the distribution information is different from each other, modify the distribution information in the distribution table to “distribution”, A distribution information control function unit for executing distribution table synchronization for overwriting the distribution table of the other communication device with the distribution information of the modified distribution table;
It is characterized by providing.

Further, the distribution table synchronization method according to the present invention includes a distribution table that holds distribution information in which “distribution” or “undistribution” of multicast data is set for each receiving device based on a multicast distribution management frame, and includes a multi-chassis LAG. A distribution table synchronization method for synchronizing the distribution table of the communication device constituting
When the distribution information held in the distribution table of one communication device matches the distribution information held in the distribution table of another communication device for each receiving device and the distribution information is different from each other, distribution of the distribution table of the first communication device Correct the information to “Delivery”
Overwriting with the distribution information of the distribution table of the first communication device that has modified the distribution table of the other communication device,
A delivery table synchronization procedure is performed.

  In the present invention, a failure has occurred in an inter-chassis line connecting communication devices constituting a multi-chassis LAG or one communication device constituting the multi-chassis LAG, and the multicast distribution table information cannot be synchronized. When there is a difference in the information of the distribution table of each communication device when recovered from the above, all are corrected to “distribution”. The present invention does not need to match the change history and can synchronize the distribution table at an early stage. Or this invention can synchronize a delivery table, without hold | maintaining a change log | history. Further, according to the present invention, when there is a difference in information in the distribution table, all of the information is corrected to “distribution”, so that the delay in starting the requested multicast distribution can be minimized.

  Note that by modifying all to “distribution”, unnecessary distribution in which data is distributed to an opposite apparatus that does not require distribution will be performed. The unnecessary distribution can be converged by further modifying the distribution table by using it.

  Therefore, the present invention can synchronize the multicast distribution table at an early stage when recovering from the failure of the inter-chassis line connecting the communication devices constituting the multi-chassis LAG or the failure of one communication device constituting the multi-chassis LAG. Communication apparatus and distribution table synchronization method can be provided.

  In addition, the communication device according to the present invention further includes a synchronization trigger unit that detects communication with the other communication device and causes the distribution information control function unit to execute the distribution table synchronization when the communication information is switched from a disconnected state to an opened state. Prepare. Failure recovery can be detected early and the delivery table can be synchronized as soon as possible.

  The present invention is a communication which can synchronize multicast distribution tables at an early stage when recovering from a failure of an inter-chassis line connecting between communication devices constituting a multi-chassis LAG or a failure of one communication device constituting a multi-chassis LAG. An apparatus and a delivery table synchronization method can be provided.

It is a figure explaining the network system using multichassis LAG. It is a figure explaining operation | movement when a failure generate | occur | produces in the circuit | line between chassis in the network system using multichassis LAG. It is a figure explaining operation | movement when a failure generate | occur | produces in the circuit | line between chassis in the network system using multichassis LAG. It is a figure explaining the structure of the communication apparatus which concerns on this invention. It is a figure explaining the delivery table synchronization after the failure recovery which the communication apparatus which concerns on this invention performs. It is a figure explaining the delivery table synchronization after the failure recovery which the communication apparatus which concerns on this invention performs. It is a figure explaining the synchronization of the delivery table which the communication apparatus which concerns on this invention performs regularly. It is a flowchart explaining the delivery table synchronization method which concerns on this invention. It is a flowchart explaining the delivery table synchronization method which concerns on this invention.

Embodiments of the present invention will be described with reference to the accompanying drawings. The embodiments described below are examples of the present invention, and the present invention is not limited to the following embodiments. In the present specification and drawings, the same reference numerals denote the same components.
In the following description, a multicast distribution table is designated as a distribution table to be synchronized with multicast distribution based on MLDv2 as an example, but this embodiment is an example of the present invention and is not limited to this embodiment. .

  FIG. 4 is a diagram illustrating the communication device SWx0 of the present embodiment. The multi-chassis LAG is composed of a communication device group of a plurality of communication devices, and a distribution table for registering distribution information necessary for transmitting distribution data held by each communication device from a specific port is transmitted via a communication device SW inter-connection port. Can be synchronized.

The communication device SWx0 is a communication device constituting a multi-chassis LAG,
A distribution table x08 holding distribution information in which “distribution” or “undistribution” of multicast data is set for each receiving device based on the multicast distribution management frame;
When the distribution information held in the distribution table (for example, 208) and the distribution information held in the distribution table (for example, 108) of another communication device are matched for each receiving device and the distribution information is different from each other, the distribution table (for example, 208) ) Distribution information control for executing distribution table synchronization in which the distribution information of the other communication device (for example, 108) is overwritten with the modified distribution information of the distribution table (for example, 208). Functional part x00;
It is characterized by providing.

  In this embodiment, in a communication device group adopting a multi-chassis LAG configuration in which a plurality of devices are virtually regarded as one device and provide a LAG connection to the opposite device, multicast distribution information updated based on MLDv2 is transmitted. A method for synchronizing is described. However, the application method of this patent is not limited to the multicast distribution or even the protocol such as MLDv2.

In a system where a plurality of physical devices are virtually regarded as one device and each device holds setting information,
If no failure has occurred, it is possible to synchronize the setting information held by individual devices by sharing the setting information,
When a failure occurs in a connection line connecting a plurality of device groups or a plurality of device groups that are virtually regarded as one device, and the failure is subsequently recovered, the setting information individually retained by the plurality of devices Matching may occur.
The communication device SWx0 provides means for repairing such inconsistencies in setting information.

In the present embodiment, in a communication device group adopting a multi-chassis LAG configuration,
The distribution information of another communication device (for example, SW10) constituting the multi-chassis LAG received via the inter-chassis line is matched with the distribution information held by the own device (for example, SW20) constituting the multi-chassis LAG. When there is distribution information that is not registered in the distribution table (for example, 208), a master device that registers the distribution information in its own distribution table;
The distribution information of the communication apparatus (for example, SW20) received via the inter-chassis line does not collide with the distribution information held by itself (for example, SW10), and the received distribution information is the distribution table of the own apparatus constituting the multi-chassis LAG. A slave device that overwrites
Set.
This setting is a feature of the multi-chassis LAG of the present disclosure that repairs inconsistencies in distribution information. In the communication device group constituting the multi-chassis LAG, a plurality of devices do not become master devices or slave devices. For example, if the communication device SW20 is a master device, the communication device SW10 is a slave device, and if the communication device SW20 is a slave device, the communication device SW10 is a master device. Which communication device is a master or a slave is set in advance. The setting of the master and the slave is necessary for repairing inconsistency in the setting information of the distribution table in a specific embodiment to be described later.

The multi-chassis LAG includes a communication device SW10, a communication device SW20, and an inter-chassis line 3 that connects the communication device SW10 and the communication device SW20.
Each communication device SWx0
Counter apparatus connection port x01, counter apparatus connection port x02, counter apparatus connection port x03, communication apparatus SW connection port x04, MC-LAG state determination function x05, distribution table information transmission process determination function x06, distribution table information reception process determination function a distribution information control function unit x00 having x07, a synchronization trigger x10, a distribution table update process confirmation function x11, and a distribution table information matching function x12;
Distribution table x08;
Distribution status confirmation function part x09,
have.

  Here, the communication device SW10 which is a slave device does not use the distribution table update process confirmation function 111 and the distribution table information matching function 112. Further, the communication device SW20 that is the master device does not use the synchronization trigger 210. For this reason, a network system may be configured using two communication apparatuses having different configurations that do not have these functional units. Alternatively, as described in the present embodiment, the communication device may include any functional unit, and the function may be invalidated by switching between the master device and the slave device according to the setting.

  The feature of the distribution table synchronization of the present embodiment is that the distribution information of the distribution tables of the communication device SW10 and the communication device SW20 constituting the multi-chassis LAG is synchronized without deleting the distribution information of the distribution table, and then The delivery table synchronized with other methods is to be corrected.

  For example, the distribution table 108 of the communication device SW10 has “distribution” distribution information for a port to a certain counter device, and the distribution table 208 of the communication device SW20 “undistributed” for a port to the certain counter device. Distribution information of “distribution” is newly recorded for the port to the counter device in the distribution table 208 (“ To "delivery").

  On the other hand, the distribution table 108 of the communication device SW10 has distribution information “undistributed” for a port to a certain counter device, and the distribution table 208 of the communication device SW20 “distributes” the port to the certain counter device. Distribution information about the port to the certain counter device in the distribution table 208 based on the distribution information “undistributed” for the port to the certain counter device registered in the distribution table 108. The distribution information of “distribution” registered in the distribution table 208 is held instead of being corrected to “undistributed”. That is, in the distribution table synchronization of this embodiment, if the distribution information of both distribution tables is different, even if the “undistributed” registered in the distribution table of the master device is modified to “distributed”, “distributed” Do not modify to “not delivered”.

  Thereafter, the distribution information registered in the distribution table of the modified master device is overwritten with the distribution information in the distribution table of the slave device.

  If the distribution table synchronization of this embodiment is adopted, it occurs after recovery from a communication device failure, a failure of an inter-chassis line connecting communication devices constituting a multi-chassis LAG, or replacement of a device group constituting a multi-chassis LAG. The distribution information mismatch of the distribution tables of the communication device SW10 and the communication device SW20 can be synchronized using only the distribution information of the distribution tables of each other. When the distribution information of both distribution tables is different, “distribution” is not corrected to “undelivered”, and therefore, multicast distribution is not stopped or delayed by the information of “undistributed” in the distribution table after the distribution table is synchronized.

  When the distribution table synchronization of the present embodiment is adopted, multicast data may be distributed even to a counterpart device that does not originally deliver. However, in MLDv2, distribution information to the counterpart device is periodically transmitted. Since the inquiry is made, the delivery is automatically stopped by correcting the delivery information in the delivery table based on the delivery information inquiry result.

  FIG. 5 and FIG. 6 describe an operation example of synchronizing the distribution tables of the communication device SW10 and the communication device SW20 that constitute the multicast LAG (MC-LAG). FIG. 5 is an operation example in which the distribution information registered in the distribution table 108 of the communication device SW10 is synchronized with the distribution table 208 of the communication device SW20. Step s10x described in the following text indicates correspondence with the flowchart of FIG.

  The MC-LAG state determination function 105 is a function for determining whether the state of the own device is a slave device or a master device (step s100).

The communication device SW10 further includes a synchronization trigger 110 that detects communication with the other communication device and causes the distribution information control function unit 100 to execute the distribution table synchronization when the communication device SW10 is switched from the disconnected state to the open state.
The synchronization trigger 110 determines whether or not the distribution information registered in the distribution table 108 is synchronized with the distribution table 208 of another communication device that configures the multichassis LAG. The condition for determining that the synchronization trigger 110 is synchronized may be a synchronization execution command based on a command from the device administrator, or may be determined by the communication device SW autonomously determining that the distribution table needs to be synchronized (step s101).

  The distribution table information transmission process determination function 106 performs the following operations on the distribution information registered in the distribution table 108 from the information of the MC-LAG state determination function 105 and the synchronization trigger 110.

The distribution table information transmission process determination function 106
If the determination of the MC-LAG state determination function 105 is “slave device” and the synchronization trigger 110 determines that “synchronization of the distribution table is necessary”, the distribution information registered in the distribution table 108 is communicated. Transmission is performed from the inter-device SW connection port 104 (step s102).
If the determination by the MC-LAG state determination function 105 is “master device” and the synchronization trigger 110 determines that “synchronization of the distribution table is unnecessary”, the distribution information registered in the distribution table 108 is communicated. No transmission is made from the inter-device SW connection port 104.

  When the determination of the MC-LAG state determination function x05 is “master device”, it will be described in the operation example of FIG. When the determination of the MC-LAG state determination function x05 is “master device”, the distribution table information transmission processing determination function x06 possessed by the communication device SWx0 does not operate with the synchronization trigger x10 as a starting point.

  The communication device SW connection port x04 is a port for connecting the communication device SW10 having the multi-chassis LAG configuration and the communication device SW20. The distribution information registered in the distribution table 108 is transmitted to the distribution information reception determination function 207 via the communication device SW connection port 104, the inter-chassis line 3, and the communication device SW connection port 204 (step s103). .

  The distribution table information reception process determination function 207 determines a method for registering distribution information registered in the distribution table 108 based on the determination of the MC-LAG state determination function 205. If the determination of the MC-LAG state determination function 205 is a master device (step s104), the distribution information registered in the distribution table 108 is transmitted to the distribution table information matching function 212 (step s105).

The distribution table information matching function 212 matches the distribution table 208 and the distribution information registered in the distribution table 108 (step s106), and performs the subsequent operations (step s107).
When the distribution information about the port to a certain opposite device is registered as “distribution” in the distribution table 108 and “undistributed” in the distribution table 208, the distribution table information matching function 212 displays the distribution table information matching function 212. The port 208 to the opposite device is corrected from “undelivered” to “distributed” (step s108).
On the other hand, when the distribution information about the port to a certain opposing device is registered as “undistributed” in the distribution table 108 and registered as “distributed” in the distribution table 208, the distribution table information matching function 212 The port to the certain counter device in the distribution table 208 remains “distributed” (not corrected) (step s109).

  FIG. 6 is an operation example in which the distribution information registered in the distribution table 208 of the communication device SW20 is synchronized with the distribution table 108 of the communication device SW10. Step s20x described in the following text indicates correspondence with the flowchart of FIG.

  The MC-LAG state determination function 205 is a function that determines whether the state of its own device is a slave device or a master device, similar to the MC-LAG state determination function 105. The MC-LAG state determination function 205 determines the state of the communication device SW20 as the master device (s200), and transmits the determination state to the distribution information transmission processing determination unit 206.

  The distribution table update process confirmation function 211 determines whether the update of the distribution information to the distribution table 208 according to the operation example described in FIG. 5 has not been updated, is being updated, or has been completed. Further, the distribution table update process confirmation function 211 transmits determination information to the distribution table information transmission process determination function 206.

  The distribution table information transmission process determination function 206 performs the following operations on distribution information registered in the distribution table 208 from the determination information transmitted from the MC-LAG state determination function 205 and the distribution table update process confirmation function 211. Is performed (step s201).

The delivery information transmission process determination unit 206
When the determination of the MC-LAG state determination function 205 is “master device” and the determination of the distribution table update process confirmation function 211 is “not updated”, the communication device SW connection port 204 registers it in the distribution table 208. Do not send the delivered distribution information.
When the determination of the MC-LAG state determination function 205 is “master device” and the determination of the distribution table update processing confirmation function 211 is “updating”, the communication device SW connection port 204 registers to the distribution table 208. Do not send the delivered distribution information.
When the determination of the MC-LAG state determination function 205 is “master apparatus” and the determination of the distribution table update process confirmation function 211 is “update end”, the communication apparatus SW connection port 204 registers in the distribution table 208. The delivered distribution information is transmitted (step s202).

  The distribution information registered in the distribution table 208 transmitted from the distribution table information transmission processing determination function 206 is the communication device SW connection port 204, the inter-chassis line 3, and the communication device SW connection port, as in the operation example of FIG. It is transmitted to the distribution table information reception process determination function 107 via 104 (step s203).

  The distribution table information reception process determination function 107 receives distribution information registered in the distribution table 208 received from the communication device SW connection port 104 from the determination of the MC-LAG state determination function 105 (step s204). The method of registering to is determined (step s205). If the determination of the MC-LAG state determination function 105 is “slave device”, the distribution table information reception processing determination function 107 displays the distribution information registered in the distribution table 208 received from the communication device SW connection port 204. The delivery table 108 is overwritten (step s206).

  Further, the communication device SWx0 periodically performs an operation for inquiring distribution information to the opposite device.

  The distribution status confirmation function unit x09 of the communication device SWx0 periodically inquires the viewing status for each piece of distribution information registered in the distribution table x08 to the opposite device connection port (x02, x03), and the response is viewed. It is determined whether it is medium or unviewed, and the following operation is performed.

The delivery status confirmation function unit x09
When inquiring about the distribution information registered in the distribution table x08 and determining that the response from the opposite device connection port (x02, x03) is being viewed, the distribution information registered in the distribution table x08 is not updated ( Leave “delivered”).
When the inquiry about the distribution information registered in the distribution table x08 is made and it is determined that the response from the opposite device connection port (x02, x03) is not viewed, the distribution information registered in the distribution table x08 is deleted (“distribution” ”To“ Undelivered ”).

  In the synchronization method shown in the operation example of FIG. 5 and FIG. 6, when the distribution information of both distribution tables is different, “distribution” is not corrected to “undistributed”, so distribution is performed even to ports that do not require distribution. However, as shown in the example of operation in Fig. 7, check the delivery status periodically and correct the delivery information for the ports that do not require delivery from "delivery" to "undelivered". Will automatically stop delivery. That is, the distribution table is automatically corrected appropriately.

  Distribution table synchronization according to the present embodiment makes it possible to synchronize distribution information between communication devices constituting a multichassis LAG without causing distribution stop or delay.

[Appendix]
The following describes the communication device of the present embodiment.
Conventionally, in any of the two communication devices constituting the multi-chassis LAG, if any communication device fails or the inter-chassis line fails, the multicast distribution table cannot be synchronized during the failure period. After the recovery from the failure, the multicast distribution table of each communication device becomes inconsistent. For this reason, there has been an abnormality in the distribution table such as loss of information of subordinate users who have received multicast. Moreover, problems such as unnecessary bandwidth compression have occurred due to the time required to normalize the distribution table.
The communication device of the present embodiment has been made for the above problem.

(1):
A communication device constituting a multi-chassis LAG (Link Aggregation Group),
Based on the multicast distribution management frame, a distribution table that stores distribution information in which “distribution” or “undistribution” of multicast data is set for each receiving device;
Matching the distribution information held in the distribution table with the distribution information held in the distribution table of another communication device for each receiving device, if the distribution information is different from each other, modify the distribution information in the distribution table to “distribution”, A distribution information control function unit for executing distribution table synchronization for overwriting the distribution table of the other communication device with the distribution information of the modified distribution table;
A communication apparatus comprising:

(2):
A communication device constituting a multi-chassis LAG (Link Aggregation Group),
Based on the multicast distribution management frame, a distribution table that stores distribution information in which “distribution” or “undistribution” of multicast data is set for each receiving device;
The distribution information held in the distribution table is transmitted to another communication device, and the other communication device matches the transmitted distribution information with the distribution information held in the distribution table of the other communication device for each receiving device, A distribution information control function unit that executes distribution table overwriting to overwrite the distribution table with the distribution information of the distribution table of the other communication device whose distribution information is corrected to “distribution” when the distribution information is different from each other;
A communication apparatus comprising:

(3):
The delivery information control function unit
The multicast distribution management frame is periodically transmitted to and received from the other communication device, and the distribution information of the distribution table is corrected based on the multicast distribution management frame from the other communication device. 1) The communication device according to (2).

  The communication apparatus according to the present embodiment performs multicast reception by combining mutual synchronization table information in an exclusive logical (OR condition) in synchronization of distribution tables with other communication apparatuses constituting the multi-chassis LAG. It is possible to reliably maintain the information of the subordinate users.

SW1, SW2, SW10, SW20: Communication devices 3-7: Counter device 8: Chassis publication lines 11-16, 21-26, 31, 32, 41, 42, 51, 52, 61, 62, 71, 72: Port 17, 27: Distribution table 100, 200: Distribution information control function units 101 to 103, 201 to 203: Port 104, 204: SW connection port 105, 205: MC-LAG state determination function 106, 206: Distribution table information transmission Process determination function 108, 208: Distribution table 109, 209: Distribution status confirmation function unit 110, 210: Synchronization trigger 111, 211: Distribution table update process confirmation function 112, 212: Distribution table information matching function

Claims (3)

A communication device constituting a multi-chassis LAG (Link Aggregation Group),
Based on the multicast distribution management frame, a distribution table that stores distribution information in which “distribution” or “undistribution” of multicast data is set for each receiving device;
Matching the distribution information held in the distribution table with the distribution information held in the distribution table of another communication device for each receiving device, if the distribution information is different from each other, modify the distribution information in the distribution table to “distribution”, A distribution information control function unit for executing distribution table synchronization for overwriting the distribution table of the other communication device with the distribution information of the modified distribution table;
A communication apparatus comprising:   The synchronization trigger unit that detects communication with the other communication device and causes the distribution information control function unit to execute the distribution table synchronization when the communication state is changed from the disconnected state to the opened state. The communication device described. Based on the multicast distribution management frame, a distribution table holding distribution information in which “distribution” or “non-distribution” of multicast data is set for each receiving apparatus is provided, and the distribution tables of the communication apparatuses constituting the multi-chassis LAG are synchronized. A delivery table synchronization method,
When the distribution information held in the distribution table of one communication device matches the distribution information held in the distribution table of another communication device for each receiving device and the distribution information is different from each other, distribution of the distribution table of the first communication device Correct the information to “Delivery”
Overwriting with the distribution information of the distribution table of the first communication device that has modified the distribution table of the other communication device,
A distribution table synchronization method characterized by performing a distribution table synchronization procedure.

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