KR20080112897A - Method for record of address transmission table in ethernet ring networks - Google Patents

Abstract

An address transfer table making method in Ethernet ring network is provided to block the generation of a loop without using a block port and to transfer a frame quickly in an optimum route. An Ethernet node transfers a ring learning frame including information for cost measurement of payload. Each Ethernet node receives two ring learning frames transmitted from the different Ethernet node. The ring learning frame including information with a minimum cost fills out the address table. The information for measuring a cost includes information about time and the number of hops.

Description

How to create an address forwarding table in an Ethernet ring network {METHOD FOR RECORD OF ADDRESS TRANSMISSION TABLE IN ETHERNET RING NETWORKS}

The present invention relates to a method for creating an address forwarding table in an Ethernet ring network, and more particularly, to a method for creating an efficient address forwarding table without creating a closed port in an Ethernet ring network.

The prior art address propagation table (eg, FDB: Filtering Database) creation method includes a method of logically or physically selecting a closed link or a closed port in order to prevent the infinite loop.

This conventional method has the advantage that the infinite loop can be easily prevented when multiple Ethernet rings are combined. However, the ring topology is changed to a loopless spanning tree structure, which reduces the overall network efficiency compared to the activation of all links.

Also, considering the size of the underlying network connected to the ring node, blocking one port or one link leads to a drastic reduction in overall network efficiency. If a link fails, the address forwarding tables on all nodes are initialized and a new address forwarding table is created. Thus, more frames are sprayed into the network than the normal state until the source address is all learned.

In the existing Ethernet ring network, the technology of blocking a port or link does not go to the optimal path, considering the capacity of the underlying network, and the network is formed in a linear tree form. There is this.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a method for creating an address forwarding table in an Ethernet ring network for improving an inefficient address forwarding table creation problem in an Ethernet ring network.

Another object of the present invention is to provide a method of creating an address forwarding table in an Ethernet ring network that can prevent a loop from being generated by intelligent address forwarding table creation without using a occlusion port and transmit a frame in an optimal path.

In order to achieve the above object, a first aspect of the present invention provides a method of creating an address forwarding table in an Ethernet ring network in which a plurality of Ethernet nodes are connected in a ring, wherein each Ethernet node costs a payload. broadcasting a ring learning frame including information for cost measurement in both directions; And each Ethernet node receives two ring learning frames transmitted from different Ethernet nodes and writes a ring learning frame with information having a minimum cost value in its address forwarding table. It is to provide an address forwarding table creation method in a ring network.

Here, each Ethernet node receiving the ring learning frame compares the source address of the received ring learning frame with its own address forwarding table, and if the source forwarding table does not have the source address in its own address forwarding table, It is preferable to designate a source address together with the port of the received ring learning frame at, and write a cost value included in the payload of the ring learning frame in its own cost table entry.

Preferably, each Ethernet node receiving the ring learning frame compares the source address of the received ring learning frame with its own address forwarding table and if the source address is present in its address forwarding table, Compares the cost value included in the payload with the cost value written in its own cost table. If the cost value included in the payload of the ring learning frame is less than the cost value written in its own cost table, it passes its address. The source address and cost values written in the table and the cost table are deleted respectively, and the source address and cost values of the received ring learning frame are newly written.

Preferably, the information for cost measurement includes information of time and hop number.

According to a second aspect of the present invention, there is provided a method of creating an address forwarding table in an Ethernet ring network in which a plurality of Ethernet nodes having a configuration of a lower network including a plurality of Ethernet stations are connected in a ring form, the address forwarding of each Ethernet node. If there is a destination address of a frame transmitted from a subnetwork of one Ethernet node in the table, but no source address exists, each Ethernet node writes the source address as a new entry in its address forwarding table, and the destination address. The present invention provides a method for creating an address forwarding table in an Ethernet ring network, characterized in that a corresponding frame is transmitted to a port corresponding to a destination address written in its own address forwarding table to be transmitted to a lower network of an Ethernet node.

According to a third aspect of the present invention, a method of creating an address forwarding table in an Ethernet ring network in which a plurality of Ethernet nodes having a configuration of a lower network including a plurality of Ethernet stations is connected in a ring form is provided. If the destination address of a frame transmitted in the lower network of any one Ethernet node is partially present in the table, the Ethernet node without the destination address is assigned a source address to the corresponding Ethernet node in the transmitted frame and the destination address. Is encapsulated by multicast, transmitted to any one port, and the Ethernet node receiving the encapsulated frame releases the encapsulated frame, checks the destination address, and transmits the address forwarding table of the corresponding Ethernet node. The destination address of the initial frame does not exist in And transmitting the broadcast to a lower network connected to the corresponding Ethernet node, and encapsulating and transmitting to the next Ethernet node again, and the Ethernet node having the destination address releases the encapsulated frame and transmits to the lower network corresponding to the destination address. Subsequently, in the lower network having the corresponding destination address, a new MAC learning frame is created by writing a source address as the corresponding destination address and the first Ethernet node written as the source address of the frame encapsulating the destination address. The present invention provides a method of creating an address forwarding table in an Ethernet ring network, characterized in that it is transmitted to a port written in an address forwarding table of a corresponding Ethernet node to arrive at a network.

In a fourth aspect of the present invention, a method of creating an address forwarding table in an Ethernet ring network in which a plurality of Ethernet nodes having a configuration of a lower network including a plurality of Ethernet stations is connected in a ring form is provided. If there is no destination address of a frame transmitted in a subnetwork of any Ethernet node in the table, each Ethernet node encapsulates the source frame with the corresponding Ethernet node and multicasts the destination address in the transmitted frame. After transmitting to any one port and receiving the encapsulated frame, the Ethernet node releases the encapsulated frame and checks the destination address so that the destination address of the initial frame does not exist in the address forwarding table of the corresponding Ethernet node. If not, go to the underlying network connected to that Ethernet node. In the Ethernet ring network characterized in that the broadcast transmission, the encapsulated back to the next Ethernet node, and transmits, and if the transmitted frame is transmitted to the Ethernet node corresponding to the source address, discard the transmitted frame and terminate. It is to provide a method of creating an address forwarding table.

A fifth aspect of the present invention provides a recording medium on which a program for executing the above-described method of creating an address forwarding table in an Ethernet ring network is recorded.

According to the method of preparing the address forwarding table in the Ethernet ring network of the present invention as described above, the port is blocked due to the increase in efficiency due to the activation of all links in the Ethernet ring network and the use of the optimal path to the destination using the cost table. It can bring higher efficiency than the technique using, and can prevent the occurrence of loop by using intelligent address forwarding table.

In addition, according to the present invention, it is possible not only to create an effective address forwarding table in an Ethernet ring topology and a subnetwork, but also to disable a link to a closed port in the existing method, thereby eliminating the disadvantage of network usage efficiency and activating all links By doing so, there is an advantage that can effectively increase the network use efficiency.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, embodiments of the present invention illustrated below may be modified in many different forms, and the scope of the present invention is not limited to the embodiments described below. The embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art.

1 is a conceptual diagram illustrating a method of creating an address forwarding table in an Ethernet ring network according to a first embodiment of the present invention.

Referring to FIG. 1, the Ethernet ring network applied to the first embodiment of the present invention includes a plurality of first to fourth Ethernet nodes A to D, and the first to fourth Ethernet nodes A to D. D) are each connected in the form of a ring.

The first Ethernet node (A) is a ring learning frame (or MAC learning frame) including information for cost measurement in address delivery tables of different Ethernet nodes, that is, the second and fourth Ethernet nodes B and D. Send by multicast.

Since the transmitted ring learning frame is transmitted in both directions, each ring node receives two ring learning frames. For example, when two ring learning frames are received at the third Ethernet node C, the cost values of the two ring learning frames are compared at the third Ethernet node C and the minimum cost value is added to its address forwarding table. Fill in the ring learning frame with

In this form, when the learning is completed by transmitting the ring learning frame for each Ethernet node, an intelligent address forwarding table that completes the optimal path using the minimum cost value is completed without infinite loop in all the address forwarding tables.

Meanwhile, the ring learning frame includes information such as a source address (SA), a time, a hop number, and the like, and the information such as the time and the hop number is included in a payload item. have.

2A to 2C are flowcharts illustrating a method of creating an address forwarding table in an Ethernet ring network according to an embodiment of the present invention, in which a ring learning frame or a MAC frame for creating an address forwarding table is received. This is a flowchart showing the process of creating an address forwarding table.

Referring to FIGS. 2A to 2C, first, the generation and transmission of an initial ring learning frame will be described. Each Ethernet node generates a general MAC frame without payload, and then generates the MAC frame. In addition to specifying the destination address (DA) as multicast, the source address (SA) as its Ethernet node.

Next, by specifying a type ID (Type ID) of the frame as a ring learning frame and broadcast transmission in both directions, each Ethernet node has all network information (e.g., , Input / output port number, lower network information, etc.) are stored in its own memory.

Therefore, it is possible to facilitate the transmission of the next ring learning frame or the general frame, and each Ethernet node can easily distinguish which port is a ring node or a lower network.

After completing the initial preparation process for smoothly performing the above frame transmission, each Ethernet node checks the type ID of the received frame to determine whether it is a ring learning frame or a general MAC frame. (S100).

As a result of the determination in step S100, if the frame received at each Ethernet node is a ring learning frame, it is determined whether the source of the corresponding ring learning frame is the current Ethernet node (S110), and if the current Ethernet node, ring learning (or MAC learning). Finish the course.

Otherwise, if the source of the ring learning frame is not the current Ethernet node, after calculating the cost value (C _f ) of the ring learning frame (S120), the information of the source address (SA) of the ring learning frame is itself. It is determined whether the address exists in the table (S130).

As a result of the determination in step S130, if the information of the source address (SA) of the corresponding ring learning frame does not exist in its own address forwarding table, the source address (SA) of the corresponding ring learning frame and the receiving port number are its own addresses. It registers in the transfer table, and registers the calculated cost value (C _f ) as the cost value (C _t ) written in its own cost table (S140).

Next, after broadcasting the corresponding ring learning frame to the ports connected to all lower networks (S150), the corresponding ring learning frame is transmitted to the next Ethernet node (S160).

On the other hand, as a result of the determination in step S130, if the information of the source address (SA) of the ring learning frame is present in its own address delivery table, write the cost value (C _f ) of the corresponding ring learning frame and its own cost table Compared and determined cost value (C _t ) (S170).

As a result of the determination in step S170, if the cost value C _f of the corresponding ring learning frame is larger than the cost value C _t written in the cost table of the corresponding Ethernet node, the flow proceeds to step S150, otherwise the corresponding ring learning is performed. If the cost value C _f of the frame is smaller than the cost value C _t written in the cost table of the Ethernet node, the flow proceeds to step S140.

On the other hand, as a result of the determination in step S100, if the frame received at each Ethernet node is a general MAC (MAC) frame, not a ring learning frame, step (A) is performed.

As shown in FIG. 2B, it is determined whether the received general MAC frame is encapsulated by a MAC-in-MAC technique (S200).

As a result of the determination in step S200, if the received MAC frame is encapsulated by a MAC-in-MAC technique, it is determined whether the source of the MAC frame is the current Ethernet node (S210). If you are an Ethernet node, you are finished with the ring learning process.

Otherwise, if the source of the general MAC frame is not the current Ethernet node, after releasing the encapsulated general MAC frame and storing MAC-in-MAC header information (S220), the general MAC (MAC) It is determined whether the information of the destination address (DA) of the frame exists in its own address forwarding table (S230), if it does not exist, if it does not exist, broadcasts the corresponding general MAC frame to all sub-networks (S240). ).

Next, after encapsulating the MAC-in-MAC header information again using the MAC-in-MAC scheme (S250), it is transmitted to the next Ethernet node (S260). Thereafter, the stored MAC-in-MAC header information is deleted (S270).

On the other hand, as a result of the determination in step S230, if the information of the destination address (DA) of the general MAC frame is present in its address forwarding table, the general MAC frame to the corresponding lower network or Ethernet station port Unicast transmission (S280).

Subsequently, a new MAC frame having a destination address (DA) of the corresponding MAC frame as a source address (SA) is generated, and the first general MAC frame encapsulated by the MAC-in-MAC technique is generated. After unicast transmission to the source address (SA) of (S290), the process proceeds to step S270.

On the other hand, if the determination result in step S200, if the received general MAC (MAC) frame is not encapsulated by the MAC-in-MAC technique, step (B) is performed.

In step (B), as shown in FIG. 2C, it is determined whether the information of the destination address DA of the corresponding MAC frame exists in its own address forwarding table (S300). Or unicast the corresponding MAC frame to the Ethernet station port (S310).

Subsequently, it is determined whether the information of the source address SA of the general MAC frame exists in its own address forwarding table (S320), and if so, the ring learning process is completed.

Otherwise, if it is determined in step S320 that the information of the source address SA of the corresponding MAC frame does not exist in its own address transfer table, the source address of the corresponding MAC frame is not present. ) And register the receiving port number in its own address forwarding table (S330), and finishes the ring learning process.

On the other hand, as a result of the determination in step S300, if the destination address (DA) of the general MAC (MAC) frame does not exist in its own address forwarding table, to all lower network and Ethernet station ports except the received port The general MAC frame is broadcasted (S340).

Subsequently, the MAC frame is encapsulated by the MAC-in-MAC scheme using the current Ethernet node as the source address (SA), and multicasted to any one of the Ethernet ports (S350). The flow proceeds to step S320.

3 is a conceptual diagram illustrating a method of creating an address forwarding table in an Ethernet ring network according to a second embodiment of the present invention, wherein a frame transmitted from one lower network to an address forwarding table of each Ethernet node (A to D) is shown in FIG. When the information of the destination address (DA) of the present exists, but the information of the source address (SA) does not exist conceptually illustrates the process of creating an address forwarding table.

Referring to FIG. 3, the Ethernet ring network applied to the second embodiment of the present invention includes a plurality of first to fourth Ethernet nodes A to D, and the first to fourth Ethernet nodes A to D. D) are each connected in the form of a ring.

Further, each of the first to fourth Ethernet nodes A to D has a first to fourth sub-network a to d including a plurality of Ethernet stations connected in a tree form.

If the first sub-network (a) of the first Ethernet node (A), the Ethernet station having the CS2 MAC (MAC, Medium Access Control) address of the third sub-network (c) of the third Ethernet node (C) as a source When transmitting a frame to an Ethernet station having a MAC address of AH5 as a destination, the information of the destination addresses DA and AH5 exists in the address forwarding table of the third Ethernet node C, but the source address SA and CS2 are present. Information does not exist.

In this case, the third Ethernet node C writes the information of the source addresses SA and CS2 into its own address forwarding table as a new entry in the address forwarding table of the third Ethernet node C, and its own address forwarding table. The frame is transmitted to the port 13 corresponding to the destination address DA and AH5.

Similarly, the second Ethernet node (B) and the first Ethernet node (A) also write the source address, that is, the information of the CS2 MAC address, as a new entry in its own address forwarding table, and the Ethernet having the destination address, that is, the AH5 MAC address. Successful transmission to the station is completed.

FIG. 4 is a conceptual diagram illustrating a method of creating an address forwarding table in an Ethernet ring network according to a third embodiment of the present invention, and is a frame transmitted from one lower network to an address forwarding table of each Ethernet node (A to D). Conceptually illustrates the process of creating an address forwarding table when partial destination address (DA) information exists.

4, the Ethernet ring network applied to the third embodiment of the present invention is configured in the same manner as the Ethernet ring network applied to the second embodiment of the present invention described above.

If the Ethernet station having the CS2 MAC address of the third sub-network c of the third Ethernet node C originates from the Ethernet having the AH5 MAC address of the first sub-network c of the first Ethernet node A, When the frame is transmitted to the station as a destination, if there is no information of the destination addresses DA and AH5 in the address forwarding table of the third Ethernet node C, the MAC defined by the Institute of Electrical and Electronics Engineers (IEEE) encapsulation by writing a source address (SA) to the corresponding Ethernet node, that is, a third Ethernet node (C), and a destination address (DA) by multicast using the -in-MAC technique. Then send it to any one port.

The second Ethernet node B receiving the frame transmitted to the next Ethernet node of the Ethernet ring network using the MAC-in-MAC technique releases the encapsulated frame and confirms a destination address DA.

At this time, if the destination address DA does not exist in the address forwarding table of the second Ethernet node B, a broadcast is transmitted to the second lower network b connected to the second Ethernet node B. The Ethernet node, that is, the third Ethernet node C is recapsulated and transmitted using the MAC-in-MAC scheme. In addition, learning of the source address SA does not occur by encapsulation of the MAC-in-MAC technique.

Repeating this process, if the destination address DA of the corresponding frame, that is, the AH5 MAC address, exists in the address forwarding table of any Ethernet node, that is, the first Ethernet node A, the first Ethernet node A encapsulates the encapsulation. Frame is released and transmitted to the AH5 MAC address of the first sub-network (a).

In addition, the frame is not transmitted to the next Ethernet node using the MAC-in-MAC technique. After this process, in the Ethernet station having the destination address DA, that is, the AH5 MAC address of the first sub-network c, the source address SA is the corresponding destination address DA, AH5, and the destination address DA is MAC. The first Ethernet node (A) is generated by generating a new MAC learning frame written with the first Ethernet node, that is, the third Ethernet node (C), written as the source address (SA) in the -in-MAC scheme. Send it in the direction of the port written in the address forwarding table. When this new Mac learning frame arrives at its destination, the general Mac learning process is complete.

FIG. 5 is a conceptual diagram illustrating a method of creating an address forwarding table in an Ethernet ring network according to a fourth embodiment of the present invention, wherein a frame transmitted from one lower network to an address forwarding table of each Ethernet node A to D is shown. Conceptually illustrates the process of creating an address forwarding table when information on the destination address (DA) does not exist.

Referring to FIG. 5, the Ethernet ring network applied to the fourth embodiment of the present invention is configured in the same manner as the Ethernet ring network applied to the second embodiment of the present invention described above.

If the Ethernet station having the CS2 MAC address of the third sub-network c of the third Ethernet node C originates, the AH5 MAC address of the first sub-network A of the first Ethernet node A originates. When transmitting the frame with the Ethernet station as the destination, if the information of the destination addresses DA and AH5 does not exist in the address forwarding table of all the first to fourth Ethernet nodes A to D, the third Ethernet node C is used. ) Is encapsulated by writing the source address (SA) to the corresponding Ethernet node, the third Ethernet node (C), and the destination address (DA) as multicast using a conventional MAC-in-MAC technique. After encapsulation, it transmits to any one port.

The second Ethernet node B receiving the frame transmitted to the next Ethernet node of the Ethernet ring network using the MAC-in-MAC technique releases the encapsulated frame and confirms a destination address DA.

At this time, if the destination address DA does not exist in the address forwarding table of the second Ethernet node B, a broadcast is transmitted to the second lower network b connected to the second Ethernet node B. The Ethernet node, that is, the third Ethernet node C is recapsulated and transmitted using the MAC-in-MAC scheme.

When this process is repeated, when the MAC node returns to the Ethernet node where the source addresses SA and CS2 of the MAC-in-MAC exist, that is, the third Ethernet node C, the MAC frame is discarded. Quit. In this case, the general MAC learning process does not occur, but the frame directed to the destination node is successfully sent due to the feature of being broadcast to the underlying network.

Briefly describing the principle of creating the intelligent address forwarding table according to the present invention, Ethernet nodes in the Ethernet ring network broadcast each ring learning frame to create an address forwarding table for MAC frame transmission. This ring learning frame contains information such as source address (SA), time, hop number, and the like.

The Ethernet node receiving the ring learning frame compares the cost value with information such as time and hop number and writes the address of the frame having the lowest cost value in its address transfer table. When both ring learning frames originating in both directions of the ring from one Ethernet node return to themselves, the other Ethernet node's address forwarding table for that Ethernet node is complete. When all the Ethernet nodes perform this process, the intelligent address forwarding table is complete.

On the other hand, a brief description of the address forwarding table in the lower network is as follows. Using Ethernet OAM (Operation, Administration and Maintenance) defined in ITU-T, Ethernet nodes form MEG (Maintenance Entity Group). Each Ethernet node in an Ethernet ring network constitutes a subnetwork.

Currently, the Ethernet MAC (MAC) is limited to about 250 lower networks by 6 byte ring learning frames due to the specification of 1500 bytes. The ring learning frame carries the MAC address of the underlying network, and the MAC address of the underlying network is loaded in the payload rather than the source address (SA).

MAC frames that are sent to an underlying network that do not exist in the Ethernet node's address forwarding table (if no destination address exists) use the MAC-in-MAC scheme defined by the IEEE.

In the MAC-in-MAC scheme, the source address (SA) of the Ethernet node, not the source address (SA) of the lower network, is written and transmitted only in one direction. When the source address SA is itself, the corresponding frame is discarded. This prevents infinite loops and optimizes ring learning.

As described above, the present invention can create an efficient address forwarding table without using a closed port or a closed link in order to efficiently configure a ring network for a Metro Ethernet service or a carrier-class Ethernet service.

In addition, the present invention can not only create an efficient address forwarding table in the Ethernet ring topology and the underlying network, but also by deactivating one link to a closed port in the existing method, eliminating the disadvantages of network efficiency and activating all links. It effectively increases network usage efficiency.

That is, in order to prepare an address forwarding table in such an efficient Ethernet ring network, frame forwarding by the address forwarding table in each Ethernet node should not form an infinite loop. This method is called an 'active management method', and the 'active management method' uses all the links of a ring, and an administrator or an arbitrary routing protocol manages the contents of each Ethernet node's address forwarding table, or the method and the Ethernet address. The combination of learning methods prevents infinite loop propagation. This is achieved by using the optimal route due to the effective address forwarding table.

Meanwhile, the method of creating an address forwarding table in an Ethernet ring network according to an embodiment of the present invention may also be embodied as computer readable codes on a computer readable recording medium. The computer-readable recording medium includes all kinds of recording devices in which data that can be read by a computer system is stored.

For example, the computer-readable recording medium may be a ROM, a RAM, a CD-ROM, a magnetic tape, a hard disk, a floppy disk, a removable storage device, a nonvolatile memory (Flash memory). Optical data storage, and the like, and also implemented in the form of a carrier wave (eg, transmission over the Internet).

The computer readable recording medium can also be distributed over computer systems connected over a computer network so that the computer readable code is stored and executed in a distributed fashion.

While a preferred embodiment of the method of creating an address forwarding table in an Ethernet ring network according to the present invention has been described above, the present invention is not limited thereto, but the scope of the claims and the detailed description of the invention and the accompanying drawings are various. It is possible to carry out the transformation by the branch and this also belongs to this invention.

1 is a conceptual diagram illustrating a method of creating an address forwarding table in an Ethernet ring network according to a first embodiment of the present invention.

2A to 2C are flowcharts illustrating a method of creating an address forwarding table in an Ethernet ring network according to an embodiment of the present invention.

3 is a conceptual diagram illustrating a method of creating an address forwarding table in an Ethernet ring network according to a second embodiment of the present invention.

4 is a conceptual diagram illustrating a method of creating an address forwarding table in an Ethernet ring network according to a third embodiment of the present invention.

5 is a conceptual diagram illustrating a method of creating an address forwarding table in an Ethernet ring network according to a fourth embodiment of the present invention.

Claims (8)

A method of creating an address forwarding table in an Ethernet ring network in which a plurality of Ethernet nodes are connected in a ring form, Each Ethernet node broadcasts a ring learning frame including information for cost measurement in a payload in both directions; And Each Ethernet node receives two ring learning frames sent from different Ethernet nodes and writes a ring learning frame with information having a minimum cost value in its address forwarding table. How to create an address forwarding table on a network. The method of claim 1, Each Ethernet node that receives the ring learning frame, Compare the source address of the received ring learning frame with its own address forwarding table and if the source address is not in its own address forwarding table, designate a source address together with the port of the received ring learning frame in its own address forwarding table. And writing a cost value included in the payload of the ring learning frame into its own cost table entry. The method according to claim 1 or 2, Each Ethernet node that receives the ring learning frame, Comparing the source address of the received ring learning frame with its own address forwarding table and if the source address is in its own address forwarding table, the cost value included in the payload of the ring learning frame and the cost address included in its own cost table are written. Comparing the cost value, if the cost value included in the payload of the ring learning frame is less than the cost value written in its own cost table, deletes the originating address and the cost value written in its own address delivery table and the cost table, respectively. And writing a new source address and a cost value of the received ring learning frame. The method of claim 1, And the information for cost measurement includes information of time and hop number. In a method for creating an address forwarding table in an Ethernet ring network in which a plurality of Ethernet nodes having a configuration of a lower network including a plurality of Ethernet stations are connected in a ring form, If each Ethernet node's address forwarding table contains a destination address for a frame sent from the Ethernet network's underlying network, but no source address exists, Each Ethernet node writes the source address as a new entry in its address forwarding table, and the corresponding frame is sent to the port corresponding to the destination address listed in its address forwarding table for transmission to the underlying network of the Ethernet node with the destination address. Method of creating an address forwarding table in an Ethernet ring network, characterized in that for transmitting. A method of creating an address forwarding table in an Ethernet ring network in which a plurality of Ethernet nodes having a configuration of a lower network including a plurality of Ethernet stations are connected in a ring form, When the destination address of a frame transmitted in the Ethernet network's underlying network partially exists in the address forwarding table of the Ethernet nodes, The Ethernet node without the destination address encapsulates the source address in the transmitted frame to the corresponding Ethernet node, multiplies the destination address in multicast, and transmits the data to an arbitrary port. Upon receiving the encapsulated frame, the Ethernet node releases the encapsulated frame and checks a destination address. Cast, send back to the next Ethernet node encapsulated, The Ethernet node in which the destination address exists, releases the encapsulated frame and transmits it to the lower network corresponding to the destination address, and then encapsulates the destination address as the corresponding destination address and the destination address in the lower network having the corresponding destination address. Ethernet which generates a new MAC learning frame written by the first Ethernet node written as the source address of the frame and transmits it to the port written in the address forwarding table of the corresponding Ethernet node to arrive at the lower network having the destination address. How to create an address forwarding table in a ring network. A method of creating an address forwarding table in an Ethernet ring network in which a plurality of Ethernet nodes having a configuration of a lower network including a plurality of Ethernet stations are connected in a ring form, If there is no destination address of a frame transmitted in the Ethernet network's subnetwork in the address forwarding table of each Ethernet node, Each Ethernet node encapsulates the source address in the transmitted frame to the corresponding Ethernet node, multicasts the destination address, and transmits the packet to any one port. The Ethernet node receiving the encapsulated frame releases the encapsulated frame, checks the destination address, and if the destination address of the initial frame does not exist in the address forwarding table of the corresponding Ethernet node, goes to a lower network connected to the Ethernet node. Broadcast, encapsulate back to the next Ethernet node, And when the transmitted frame is transmitted to the Ethernet node corresponding to the source address, discarding the transmitted frame to terminate the transmitted frame. A computer-readable recording medium having recorded thereon a program capable of executing the method of any one of claims 1 to 7.

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