JP2012049833A - Network relay device and network relay method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique with which it becomes possible to make a layer 2 network redundant.SOLUTION: A network relay device 100 includes: an uplink redundant unit 122 that makes a computer network 10 redundant in units of physical lines by selecting one of a physical line P1 and a physical line P2 as a physical line for communication; and a group management unit 123 that makes the computer network 10 redundant in units of logical lines by selecting, out of logical lines common to both of the physical line P1 and a physical line P3, a logical line set for one of the physical lines as a logical line for communication through cooperation with the uplink redundant unit 122.

Description

  The present invention relates to a network relay device and a network relay method for making a layer 2 network redundant.

  As a technique for making a layer 2 network redundant, a spanning tree protocol standardized as IEEE 802.1d is known. In the spanning tree protocol, a layer 2 network that logically eliminates the loop configuration of a route is obtained by periodically exchanging control frames called BPDUs (Bridge Protocol Data Units) between network relay devices to perform route calculation. It is possible to realize the redundancy of the layer 2 network after the construction.

  As another method for making a layer 2 network redundant, uplink redundant (hereinafter also referred to as “ULR”) is known (see Non-Patent Document 1). In uplink redundant, a pair of physical lines are assigned to the uplink, one physical line is used as an active port for communication, the other physical line is made standby as a standby port, and if the active port fails, the standby Switch the port to the active port and use it for communication. Generally, when a logical line for constructing a virtual local area network (hereinafter referred to as “VLAN”) is set to a pair of physical lines to which uplink redundancy is applied, the same is performed before and after the occurrence of the failure. In order to maintain communication via the logical line, a common logical line is set for the active port and the standby port.

“AX3600S Software Manual Configuration Guide Vol.2 Ver.11.4 Compatible”, ALAXALA Networks Corporation, April 2010, 389-404

  Compared with the spanning tree protocol, the conventional uplink redundant can simplify and speed up the processing required for redundancy, but the logical lines set for each physical line of the active port and standby port There was not enough consideration. For example, in conventional uplink redundancy, a common logical line is set for the active port and the standby port, and only the active port is used for communication with the standby port waiting. However, depending on the network configuration, the standby port may be However, there are cases where there is a logical line that can shorten the network path, and conversely, a logical line that complicates the network path due to port switching when a failure occurs. As described above, the conventional uplink redundancy has a problem that a logical line cannot be set in consideration of the data transfer efficiency of the entire layer 2 network.

  In view of the above-described problems, an object of the present invention is to provide a technique capable of making a layer 2 network redundant.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

  Application Example 1 The network relay device of Application Example 1 is a network relay device that relays communication data in a layer 2 network, and is connected to a first physical port connected to the first physical line and a second physical line. A first redundancy unit configured to make the layer 2 network redundant in units of physical lines by selecting one of the second physical port and the first physical line or the second physical line as a physical line used for communication. One of the logical lines common to both the first physical line and the third physical line in cooperation with the third physical port connected to the third physical line and the first redundancy unit. A second redundancy unit configured to make the layer 2 network redundant in units of logical lines by selecting a logical line set as a physical line as a logical line to be used for communication. And butterflies. According to the network relay device of Application Example 1, the third physical line is used for the logical line set as the first physical line in accordance with the physical line unit redundancy of the first physical line and the second physical line. Redundancy can be implemented in units of logical lines. Thereby, it is possible to make the layer 2 network redundant while setting the logical line in consideration of the data transfer efficiency of the entire layer 2 network.

  Application Example 2 In the network relay device of Application Example 1, one of the logical lines set as the first physical line is common to the logical line set as the third physical line, and the second physical line is set. It may be different from any of the logical lines set for the line. According to the network relay device of application example 2, among the logical lines set as the first physical line, the logical line that is inconvenient in terms of data transfer efficiency is not set as the second physical line in the second physical line. By setting the third physical line, it is possible to make the layer 2 network redundant while avoiding a decrease in data transfer efficiency.

  Application Example 3 In the network relay device of Application Example 1 or Application Example 2, the first redundancy unit is a case where the other physical line different from the one used for communication is recovered from a failure. Alternatively, the selection of the one physical line may be maintained. According to the network relay device of application example 3, frequent switching of the physical line used for communication between the first physical line and the second physical line is suppressed, and the delay of data relay due to the switching of the physical line is reduced. Can be prevented.

  Application Example 4 In the network relay device of any one of Application Example 1 to Application Example 3, the second redundancy unit recovers from the failure of the other logical line different from the one logical line currently used for communication. Even in this case, the selection of the one logical line may be maintained. According to the network relay device of the application example 4, frequent switching of the logical line used for communication between the first physical line and the third physical line is suppressed, and the delay of data relay accompanying switching of the logical line is reduced. Can be prevented.

  Application Example 5 The network relay device according to Application Example 1 to Application Example 4 further cooperates with the fourth physical port connected to the fourth physical line and the first redundancy unit, to Of the logical lines common to both the two physical lines and the fourth physical line, the logical line set to one of the physical lines is selected as the logical line used for communication, thereby making the layer 2 network a logical line. You may provide the 3rd redundancy part made redundant in a unit. According to the network relay device of Application Example 5, the third physical line is used for the logical line set as the first physical line in accordance with the physical line unit redundancy of the first physical line and the second physical line. Thus, the logical line set as the second physical line can be made redundant in units of logical lines using the fourth physical line.

  Application Example 6 In the network relay device of Application Example 5, one of the logical lines set as the first physical line is common to the logical line set as the third physical line, and the second physical line is set. And the logical line set for each of the fourth physical lines may be different. According to the network relay device of the application example 6, among the logical lines set as the first physical line, the second physical line and the fourth physical line are not logical lines that are inconvenient in terms of data transfer efficiency. By setting the third physical line without setting the fourth physical line, it is possible to achieve redundancy of the layer 2 network while avoiding a decrease in data transfer efficiency.

  Application Example 7 In the network relay device of Application Example 5 or Application Example 6, the third redundancy unit is a case where the other logical line different from the one used for communication is recovered from a failure. Alternatively, the selection of the one logical line may be maintained. According to the network relay device of the application example 7, frequent switching of the logical line used for communication between the second physical line and the fourth physical line is suppressed, and the delay of data relay accompanying the switching of the logical line is reduced. Can be prevented.

  Application Example 8 The network relay method of Application Example 8 is a network relay method for relaying communication data in a layer 2 network, in which logical lines are set for the first physical line and the second physical line, respectively. By selecting one of the physical line and the second physical line as a physical line to be used for communication, first redundancy is performed to make the layer 2 network redundant in units of physical lines, and A logical line common to the first physical line is set, and the logic set to one physical line among the logical lines common to both the first physical line and the third physical line is set together with the first redundancy. By selecting a line as a logical line to be used for communication, the second redundancy is performed to make the layer 2 network redundant in units of logical lines. . According to the network relay method of Application Example 8, the third physical line is used for the logical line set as the first physical line in accordance with the redundancy of the first physical line and the second physical line in units of physical lines. Redundancy can be implemented in units of logical lines. Thereby, it is possible to make the layer 2 network redundant while setting the logical line in consideration of the data transfer efficiency of the entire layer 2 network.

  The form of the present invention is not limited to the network relay apparatus and the network relay method. For example, the present invention may be applied to other forms such as a network system including a plurality of network relay apparatuses, a program for causing a computer to realize the functions of the network relay apparatuses. It can also be applied. Further, the present invention is not limited to the above-described embodiments, and it is needless to say that the present invention can be implemented in various forms without departing from the spirit of the present invention.

It is explanatory drawing which shows the structure of a computer network. It is explanatory drawing which shows the structure of a network relay apparatus. It is explanatory drawing which shows the detailed structure of the control part of a network relay apparatus. It is explanatory drawing which shows the physical line and logical line of the network relay apparatus at the time of initialization. It is explanatory drawing which shows the line management database of the network relay apparatus at the time of initialization. It is explanatory drawing which shows the network path | route at the time of initialization. It is a flowchart which shows the line setting process which the control part of a network relay apparatus performs. It is a flowchart which shows the standby port setting process which the control part of a network relay apparatus performs. It is a flowchart which shows the physical line down process which the control part of a network relay apparatus performs. It is explanatory drawing which shows the physical line and logical line of the network relay apparatus in a 1st transition state. It is explanatory drawing which shows the line management database of the network relay apparatus in a 1st transition state. It is explanatory drawing which shows the network path | route in a 1st transition state. It is explanatory drawing which shows the physical line and logical line of a network relay apparatus in a 2nd transition state. It is explanatory drawing which shows the line management database of the network relay apparatus in a 2nd transition state. It is explanatory drawing which shows the physical line and logical line of a network relay apparatus in a 3rd transition state. It is explanatory drawing which shows the line management database of the network relay apparatus in a 3rd transition state. It is explanatory drawing which shows the network path | route in a 3rd transition state. It is explanatory drawing which shows the physical line and logical line of the network relay apparatus in a 4th transition state. It is explanatory drawing which shows the line management database of the network relay apparatus in a 4th transition state. It is explanatory drawing which shows the physical line and logical line of the network relay apparatus in a 5th transition state. It is explanatory drawing which shows the line management database of the network relay apparatus in a 5th transition state. It is explanatory drawing which shows the network path | route in a 5th transition state. It is explanatory drawing which shows the physical line and logical line of the network relay apparatus in a 6th transition state. It is explanatory drawing which shows the line management database of the network relay apparatus in a 6th transition state. It is explanatory drawing which shows the network path | route in a 6th transition state.

  In order to further clarify the configuration and operation of the present invention described above, a computer network to which the present invention is applied will be described below.

A. Example:
A1. Computer network configuration:
FIG. 1 is an explanatory diagram showing the configuration of the computer network 10. The computer network 10 includes a network relay device 100, a terminal device 200, and a server 300. In this embodiment, the computer network 10 is connected to a wide area network 400 such as the Internet. The numbers of the network relay device 100, the terminal device 200, the server 300, and the wide area network 400 shown in FIG. 1 are merely examples, and the numbers can be increased or decreased in other embodiments.

  The terminal device 200 of the computer network 10 is a computer that exchanges data with other terminal devices 200, the server 300, and the wide area network 400 through the network relay device 100. In the description of the present embodiment, the symbol “200” is used to generally indicate a terminal device, and the symbol with an alphabetic character after “200” is used to indicate a specific terminal device. In FIG. 1, three terminal devices are illustrated, and the reference numerals “200a”, “200b”, and “200c” are used for each.

  The server 300 of the computer network 10 is a computer that exchanges data with the terminal device 200 through the network relay device 100. In the description of the present embodiment, the symbol “300” is used to generally indicate a server, and the symbol with an English letter after “300” is used to indicate a specific server. In FIG. 1, two servers are illustrated, and the codes “300a” and “300b” are used for each.

  The network relay device 100 of the computer network 10 is a layer 2 switch that realizes a transfer method compliant with layer 2 which is a data link layer protocol in an OSI (Open System Interconnection) reference model, and includes a terminal device 200, a server 300, and a wide area. A network 2 is connected to each other to construct a layer 2 network. In the description of the present embodiment, a symbol “100” is used to generally indicate a network relay device, and a symbol with an alphabetic character after “100” is used to indicate a specific network relay device. Use. In FIG. 1, five network relay apparatuses are illustrated, and the reference numerals “100a”, “100b”, “100c”, “100d”, and “100e” are used for each.

  The network relay device 100 includes a physical port for exchanging data frames conforming to layer 2. In the description of the present embodiment, when the five physical ports of the network relay device 100 are generally indicated, the symbols “11”, “12”, “13”, “14”, and “15” are used, respectively. In the case of indicating a specific physical port, a code in which an alphabetic character added to the code of the network relay device 100 is appended to the number is used. For example, the symbols “11a”, “12a”, “13a”, “14a”, and “15a” are used for the five physical ports included in the network relay device 100a.

  The physical ports 11a and 13a of the network relay device 100a are connected to the network relay device 100b, and the physical ports 12a and 14a are connected to the network relay device 100c. Three terminal devices 200a, 200b, and 200c are connected to the physical port 15a of the network relay device 100a.

  By applying uplink redundancy to the physical ports 11a and 12a in the network relay device 100a, the computer network 10 is made redundant in units of physical lines connected to the physical ports 11a and 12a. In this embodiment, the physical port 11a is set as a primary port, and the physical port 12a is set as a secondary port. In the state of FIG. 1, the physical port 11a is set as an active port, and the physical port 12a is set as a standby port.

  In the network relay device 100a, the physical ports 11a and 13a are grouped to form one group interface, and the physical ports 12a and 14a are grouped to form one group interface. , 12a, 13a, and 14a are made redundant in units of logical lines set for each physical line. Details of the group interface and logical line unit redundancy will be described later.

  The physical ports 11b and 15b of the network relay device 100b are connected to the network relay device 100a, and the physical port 14b is connected to the server 300a. The physical port 12b of the network relay device 100b is connected to the network relay device 100e, and the physical port 13b is connected to the network relay device 100d. Uplink redundancy is applied to the physical ports 12b and 13b. In the state of FIG. 1, the physical port 13b is set as an active port, and the physical port 12b is set as a standby port.

  The physical ports 11c and 15c of the network relay device 100c are connected to the network relay device 100a, and the physical port 14c is connected to the server 300b. The physical port 12c of the network relay device 100c is connected to the network relay device 100d, and the physical port 13c is connected to the network relay device 100e. Uplink redundancy is applied to the physical ports 12c and 13c. In the state of FIG. 1, the physical port 12c is set as an active port, and the physical port 13c is set as a standby port.

  The physical port 11d of the network relay device 100d is connected to the network relay device 100b, and the physical port 12d is connected to the wide area network 400. The physical port 13d of the network relay device 100d is connected to the network relay device 100e, and the physical port 14d is connected to the network relay device 100c.

  The physical port 11e of the network relay device 100e is connected to the network relay device 100c, and the physical port 12e is connected to the wide area network 400. The physical port 13e of the network relay device 100e is connected to the network relay device 100d, and the physical port 14e is connected to the network relay device 100b.

  In the computer network 10, a plurality of logical networks 500a, 500b, 500c, and 500z are set as VLANs. Network relay devices 100a and 100b, terminal devices 200a and 200b, and a server 300a belong to the logical network 500a. Network relay devices 100a and 100c, terminal devices 200b and 200c, and a server 300b belong to the logical network 500b. All of the nodes belonging to the logical networks 500a and 500b belong to the logical network 500c. Five network relay devices 100a to 100e and three terminal devices 200a to 200c belong to the logical network 500z.

  FIG. 2 is an explanatory diagram showing the configuration of the network relay device 100. The network relay device 100 includes a control unit 110, a transfer unit 150, and an interface unit 180. The control unit 110 of the network relay device 100 controls operations of the transfer unit 150 and the interface unit 180. The transfer unit 150 of the network relay device 100 performs processing for transferring the data frame received by the interface unit 180 to another node. The interface unit 180 of the network relay device 100 includes a plurality of physical ports connected to a physical line such as a twisted pair cable or an optical fiber compliant with layer 2.

  FIG. 3 is an explanatory diagram illustrating a detailed configuration of the control unit 110 of the network relay device 100. The control unit 110 includes a CPU (Central Processing Unit) 120 and a storage unit 130. The CPU 120 of the control unit 110 executes various processes based on the control program 131 stored in the storage unit 130. The control unit 110 includes a physical line monitoring unit 121, an uplink redundancy unit 122, and a group management unit 123 as functions realized by the CPU 120 operating based on the control program 131. In another embodiment, at least some of the functions of the physical line monitoring unit 121, the uplink redundancy unit 122, and the group management unit 123 are not realized by a computer program, but the control unit 110 is based on the electric circuit configuration. It may be realized by operating.

  The physical line monitoring unit 121 of the control unit 110 monitors the state of the physical line connected to each physical port in the interface unit 180. In this embodiment, the physical line monitoring unit 121 detects the occurrence of a failure in the physical line and the recovery from the failure based on the information from the transfer unit 150.

  The uplink redundancy unit 122 of the control unit 110 is a first redundancy unit that realizes uplink redundancy. The uplink redundant unit 122 makes the computer network 10 redundant in units of physical lines by selecting one of a pair of physical lines connected to the physical line in the interface unit 180 as a physical line used for communication. In the description of the present embodiment, a physical line to which uplink redundancy is applied by the uplink redundant unit 122 is also referred to as “ULR physical line”.

  The group management unit 123 of the control unit 110 is a second redundancy unit and a third redundancy unit that realizes redundancy of the computer network 10 in cooperation with the uplink redundancy unit 122. The group management unit 123 manages one of the pair of ULR physical lines and a physical line different from the ULR physical line as a group interface. In the description of this embodiment, physical lines grouped by the group management unit 123 are also referred to as “group physical lines”. The group management unit 123 selects a logical line set for one group physical line as a logical line used for communication among the logical lines common to both of the paired group physical lines. The computer network 10 is made redundant in units of logical lines.

  Based on the operations of the uplink redundant unit 122 and the group management unit 123, the control unit 110 determines a logical line where communication is promoted and a logical line where communication is blocked. In the description of this embodiment, the state of the logical line in which communication is promoted is referred to as “forwarding state”, and the state of the logical line in which communication is blocked is referred to as “blocking state”.

  In addition to the control program 131, setting information 132 and a line management database 140 are stored in the storage unit 130 of the control unit 110. The setting information 132 in the storage unit 130 is various information set by the administrator of the network relay device 100, and the control unit 110 operates based on the setting information 132. The line management database 140 of the storage unit 130 is information for managing physical lines and logical lines in the interface unit 180, and the control unit 110 manages line management based on the operations of the uplink redundant unit 122 and the group management unit 123. The database 140 is maintained and the operations of the transfer unit 150 and the interface unit 180 are controlled based on the line management database 140.

  FIG. 4 is an explanatory diagram showing physical lines and logical lines of the network relay device 100a at the time of initial setting. The physical ports 11a, 12a, 13a, 14a, and 15a of the network relay device 100a have physical port identifiers “0/25”, “0/26”, “0/1”, “0/2” for identifying physical ports. , “0/10” are assigned.

  A physical line P1, which is a first physical line wired to the network relay device 100b, is connected to the physical port 11a of the network relay device 100a, and logical lines L11a, L12c, and L13z are set to the physical line P1. Yes. The logical line L11a constructs a logical network 500a, the logical line L12c constructs a logical network 500c, and the logical line L13z constructs a logical network 500z.

  A physical line P2 that is a second physical line wired to the network relay device 100c is connected to the physical port 12a of the network relay device 100a, and logical lines L21b, L22c, and L23z are set in the physical line P2. Yes. The logical line L21b constructs a logical network 500b, the logical line L22c constructs a logical network 500c, and the logical line L23z constructs a logical network 500z.

  A physical line P3 which is a third physical line wired to the network relay device 100b is connected to the physical port 13a of the network relay device 100a, and logical lines L31a and L32c are set in the physical line P3. The logical line L31a is a logical line common to the logical line L11a set in the physical port 11a, and constructs a logical network 500a. The logical line L32c is a logical line common to the logical line L12c set in the physical port 11a, and constructs a logical network 500c.

  A physical line P4 that is a fourth physical line wired to the network relay apparatus 100c is connected to the physical port 14a of the network relay apparatus 100a, and logical lines L41b and L42c are set in the physical line P4. The logical line L41b is a logical line common to the logical line L21b set in the physical port 12a, and constructs a logical network 500b. The logical line L42c is a logical line common to the logical line L22c set to the physical port 12a, and constructs a logical network 500c.

  A physical line P5 wired to a plurality of terminal devices 200 is connected to the physical port 15a of the network relay device 100a, and logical lines L51a, L52b, L53c, and L54z are set. The logical line L51a constructs a logical network 500a, and the logical line L52b constructs a logical network 500b. The logical line L53c constructs a logical network 500c, and the logical line L54z constructs a logical network 500z.

  In the description of the present embodiment, among the plurality of logical lines set in the network relay device 100a, logical lines having the same alphabetical character are common logical lines that construct the same logical network 500. For example, the logical lines L12c, L22c, L32c, L42c, and L53c are common logical lines that construct the same logical network 500c.

  FIG. 5 is an explanatory diagram showing the line management database 140 of the network relay device 100a at the time of initial setting. The line management database 140 includes fields 141, 142, 143, 144, 145, 146, and 147 for storing various types of information.

  Information stored in the field 141 of the line management database 140 indicates an identifier for identifying group interfaces grouped by the group management unit 123. Information stored in the field 142 of the line management database 140 indicates an identifier for identifying a physical port in the interface unit 180.

  Information stored in the field 143 of the line management database 140 indicates an identifier for identifying a physical line connected to the physical port. The information stored in the field 144 of the line management database 140 indicates information indicating the state of the physical line, and in this embodiment, the state of the physical line is “Up” state indicating normal operation. , “Down” state indicating that the device does not operate normally due to a failure.

  Information stored in the field 145 of the line management database 140 indicates an identifier for identifying a logical line set as a physical line, and in this embodiment, includes an identifier for identifying a VLAN. The information stored in the field 146 of the line management database 140 indicates information indicating the state of the logical line. In this embodiment, in addition to the “forwarding” state and the “blocking” state, the information is normally operated when the physical line is down. Indicates a “down” state indicating no operation.

  The information stored in the field 147 of the line management database 140 indicates a blocking factor that is a factor that causes the logical line to be in a blocking state. In the present embodiment, the blocking factor “ULR” indicates ULR blocking that is blocking by the uplink redundant unit 122. The blocking factors “G1” and “G2” indicate group blocking that is blocking by the group management unit 123. In particular, the blocking factor “G1” indicates group blocking caused by the group interface G1, and the blocking factor “G2”. "Indicates group blocking caused by the group interface G2.

  As shown in FIG. 5, in this embodiment, the physical port 11a specified by the physical port identifier “0/25” is an uplink redundant primary port, and is specified by the physical port identifier “0/26”. The physical port 12a is an uplink redundant secondary port. In the initial setting shown in FIGS. 4 and 5, since the physical port 11a to which the physical line P1 is connected is an active port, the logical lines L11a, L12c, and L13z set to the physical line P1 are set to the forwarding state. ing. In the initial setting shown in FIGS. 4 and 5, the physical port 12a to which the physical line P2 is connected is a standby port, so the logical lines L21b, L22c, and L23z set to the physical line P2 are set to the blocking state. Has been.

  As shown in FIGS. 4 and 5, in this embodiment, the physical line P3 constitutes the group interface G1 together with the physical line P1 which is the ULR physical line, and the logical lines L31a and L32c set to the physical line P3 are This is a logical line common to the logical lines L11a and L12c set to the physical line P1. 4 and 5, the logical lines L11a and L12c set to the physical line P1 are set to the forwarding state at the time of initial setting, and thus the logical lines L31a and L32c set to the physical line P3 are set to the blocking state. Is set.

  As shown in FIGS. 4 and 5, in this embodiment, the physical line P4 forms a group interface G2 together with the physical line P2 that is an ULR physical line, and the logical lines L41b and L42c set in the physical line P4 are This is a logical line common to the logical lines L21b and L22c set to the physical line P2. In the initial setting shown in FIGS. 4 and 5, the logical lines L21b and L22c set to the physical line P2 are set to the blocking state. Therefore, the logical lines L41b and L42c set to the physical line P4 are set to the forwarding state. Is set.

  FIG. 6 is an explanatory diagram showing a network route at the time of initial setting. In the initial setting described with reference to FIGS. 4 and 5, a network route is formed as shown in FIG. The network path Ra formed between the terminal devices 200a and 200b and the server 300a in the logical network 500a uses two network relay devices by using the physical line P1 connected to the physical port 11a of the network relay device 100a. The route goes through 100a and 100b. The network route Rb formed between the terminal devices 200b, 200c and the server 300b in the logical network 500b uses two network relay devices by using the physical line P4 connected to the physical port 14a of the network relay device 100a. The route goes through 100a and 100c. The network route Rz formed between the terminal devices 200a, 200b, and 200c and the wide area network 400 in the logical network 500z uses three physical lines P1 connected to the physical port 11a of the network relay device 100a, thereby providing three The route goes through the network relay devices 100a, 100b, and 100d.

A2. Computer network behavior:
A2-1. Line setting processing:
FIG. 7 is a flowchart showing the line setting process (step S100) executed by the control unit 110 of the network relay device 100. The line setting process (step S100) is a process for setting the ULR physical line of the active port or the group physical line that is a pair of the ULR physical line. In the present embodiment, the line setting process (step S100) is realized by the CPU 120 of the control unit 110 operating based on the control program 131. The control unit 110 of the network relay device 100 sets a line when setting a physical port connected to an ULR physical line as an active port, or when setting a newly established group physical line and a group physical line to be recovered from a failure. The setting process (step S100) is started.

  When starting the line setting process (step S100), the control unit 110 of the network relay device 100 executes the target line specifying process (step S110). In the target line identification processing (step S110), the control unit 110 operates as the uplink redundant unit 122 and the group management unit 123, thereby performing the target physical that is the physical line to be processed in the line setting processing (step S100). Identify the line. The target physical line of the line setting process (step S100) is a ULR physical line in which the connected physical port is set as an active port, a newly established group physical line, and a group physical line to be recovered from a failure.

  After the target line specifying process (step S110), the control unit 110 operates as the physical line monitoring unit 121, and belongs to the same group interface as the target physical line specified in the target line specifying process (step S110). The state of the group physical line is determined (step S120).

  When another group physical line that is a pair of the target physical line is in a down state (step S120: “DOWN”), the control unit 110 operates as the group management unit 123, thereby setting the logical set in the target physical line. All the lines are set to the forwarding state (step S170). Thereafter, the control unit 110 ends the line setting process (step S100).

  When another group physical line that is a pair of the target physical line is in an up state (step S120: “UP”), the control unit 110 identifies one of the logical lines set as the target physical line as a specific logical line. (Step S130). Thereafter, the control unit 110 determines whether or not a common logical line, which is a logical line for constructing a logical network common to the specific logical line, is set in another group physical line that is a pair of the target physical lines ( Step S141). When a common logical line is set for another group physical line (step S141: “YES”), the control unit 110 determines the state of the common logical line (step S142).

  When the common logical line set to another group physical line is in the forwarding state (step S142: “forwarding”), the control unit 110 operates as the group management unit 123 to specify the specific physical line set to the target physical line. The logical line is set to a blocking state (step S151). The blocking factor in this case is group blocking by the group management unit 123.

  When no common logical line is set for another group physical line (step S141: “NO”), or when a common logical line set for another group physical line is in a blocking state (step S142: “blocking”). The control unit 110 operates as the group management unit 123 to set the specific logical line set as the target physical line to the forwarding state (step S152).

  After processing all the logical lines set as the target physical line as specific logical lines (step S160: “YES”), the control unit 110 ends the line setting process (step S100).

A2-2. Standby port setting process:
FIG. 8 is a flowchart showing standby port setting processing (step S200) executed by the control unit 110 of the network relay device 100. The standby port setting process (step S200) is a process for setting the ULR physical line of the standby port. In this embodiment, the standby port setting process (step S <b> 200) is realized by the CPU 120 of the control unit 110 operating based on the control program 131. When the physical port connected to the ULR physical line is set as a standby port, the control unit 110 of the network relay device 100 starts standby port setting processing (step S200).

  When starting the standby port setting process (step S200), the control unit 110 of the network relay device 100 executes the target line specifying process (step S210). In the target line specifying process (step S210), the control unit 110 operates as the uplink / redundant unit 122 to specify a target physical line that is a physical line to be processed in the standby port setting process (step S200). . The target physical line of the standby port setting process (step S200) is an ULR physical line in which the connected physical port is set as a standby port.

  After the target line specifying process (step S210), the control unit 110 operates as the physical line monitoring unit 121, and belongs to the same group interface as the target physical line specified by the target line specifying process (step S210). The state of the group physical line is determined (step S220).

  When another group physical line that is a pair of the target physical line is in the down state (step S220: “DOWN”), the control unit 110 is set as the target physical line by operating as the uplink redundant unit 122. All the logical lines are set to the blocking state (step S270). The blocking factor in this case is ULR blocking by the uplink redundant unit 122. Thereafter, the control unit 110 ends the standby port setting process (step S200).

  When another group physical line that is a pair of the target physical line is in an up state (step S220: “UP”), the control unit 110 identifies one of the logical lines set as the target physical line as a specific logical line. (Step S230). Thereafter, the control unit 110 determines whether or not a common logical line, which is a logical line for constructing a logical network common to the specific logical line, is set in another group physical line that is a pair of the target physical lines ( Step S241). When a common logical line is set for another group physical line (step S241: “YES”), the control unit 110 determines the state of the common logical line (step S242).

  When no common logical line is set for another group physical line (step S241: “NO”), or when a common logical line set for another group physical line is in a forwarding state (step S242: “forwarding”). The controller 110 operates as the uplink redundant unit 122 to set the specific logical line set as the target physical line to the blocking state (step S257). The blocking factor in this case is ULR blocking by the uplink redundant unit 122.

  When the common logical line set to another group physical line is in the blocking state (step S242: “blocking”), the control unit 110 performs the group management unit 123 together with the blocking setting of the specific logical line (step S257). As a result, the common logical line set to another group physical line is set to forwarding (step S255).

  After processing all the logical lines set as the target physical line as specific logical lines (step S260: “YES”), the control unit 110 ends the standby port setting process (step S200).

A2-3. Physical line down processing:
FIG. 9 is a flowchart showing physical line down processing (step S300) executed by the control unit 110 of the network relay device 100. The physical line down process (step S300) is a process of setting a logical line when the physical line is down. In this embodiment, the physical line down process (step S300) is realized by the CPU 120 of the control unit 110 operating based on the control program 131. When the physical line connected to the physical port of the interface unit 180 goes down, the control unit 110 of the network relay device 100 starts physical line down processing (step S300).

  When starting the physical line down process (step S300), the control unit 110 of the network relay device 100 executes the down line specifying process (step S310). In the down line specifying process (step S310), the control unit 110 operates as the physical line monitoring unit 121 to specify a down physical line that is a down physical line.

  After the physical line down process (step S310), the control unit 110 operates as the physical line monitoring unit 121, and belongs to the same group interface as the down physical line specified in the down line specification process (step S310). The state of the group physical line is determined (step S320).

  When the other group physical line that is paired with the down physical line is in the down state (step S320: “DOWN”), the control unit 110 sets all the logical lines set to the down physical line to the down state ( Step S370). Thereafter, the control unit 110 ends the physical line down process (step S300).

  When another group physical line that is paired with the down physical line is in the up state (step S320: “UP”), the control unit 110 identifies one of the logical lines set as the down physical line as a specific logical line. (Step S330). Thereafter, the control unit 110 determines whether or not a common logical line, which is a logical line for constructing a logical network common to the specific logical line, is set in another group physical line that is a pair of down physical lines ( Step S341). When a common logical line is set for another group physical line (step S341: “YES”), the control unit 110 determines the state of the common logical line (step S342). When the common logical line set to another group physical line is in the blocking state (step S342: “blocking”), the control unit 110 determines the blocking factor (step S343).

  When no common logical line is set for another group physical line (step S341: “NO”), or when a common logical line set for another group physical line is in a forwarding state (step S342: “forwarding”). ) When the blocking factor of the common logical line set to another group physical line is ULR blocking (step S343: “ULR”), the control unit 110 puts the specific logical line set to the down physical line in the down state. (Step S358).

  When the blocking factor of the common logical line set for another group physical line is group blocking (step S343: “group”), the control unit 110, in conjunction with the specific logical line down setting (step S358), By operating as the group management unit 123, the common logical line set to another group physical line is set to forwarding (step S355).

  After processing all of the logical lines set as down physical lines as specific logical lines (step S360: “YES”), the control unit 110 ends the physical line down process (step S300).

A2-4. Example of operation:
<First transition state>
FIG. 10 is an explanatory diagram showing physical lines and logical lines of the network relay device 100a in the first transition state. FIG. 11 is an explanatory diagram showing the line management database 140 of the network relay device 100a in the first transition state. FIG. 12 is an explanatory diagram showing a network path in the first transition state. The first transition state shown in FIG. 10, FIG. 11 and FIG. 12 shows the state transitioned from the initial setting state shown in FIG. 4, FIG. 5 and FIG.

  If a failure occurs in the physical line P1 in the initial setting state, the physical line P1 changes from the up state to the down state, and the control unit 110 of the network relay device 100a performs the physical line down process (step S300 in FIG. 9). Execute. In the physical line down process (step S300 in FIG. 9) in the first transition state, the control unit 110 identifies the physical line P1 as a down physical line (step S310 in FIG. 9), and sets the physical line P3 to another group physical line. (Step S320 in FIG. 9).

  The physical line P3 is in the up state (step S320 in FIG. 9: “UP”), and the logical lines L31a and L32c, which are the common logical lines of the logical lines L11a and L12c set in the physical line P1, are blocked by group blocking. (Step S343 in FIG. 9: “Group”), the control unit 110 switches the logical lines L31a and L32c set for the physical line P3 from the blocking state to the forwarding state (Step S355 in FIG. 9). For the logical line L13z set to the physical line P1, since there is no common logical line in the physical line P3 (step S341: “NO” in FIG. 9), the control unit 110 adds the logical line L13z of the physical line P1. There is no need to change the setting of the physical line P3. Along with the setting related to the physical line P3, the control unit 110 switches the logical lines L11a, L12c, and L13z set to the physical line P1 from the forwarding state to the down state (step S358 in FIG. 9).

  Control of the network relay device 100a to switch the physical port 12a to which the physical line P2 is connected from the standby port to the active port in accordance with the down state of the physical line P1 that was the ULR physical line of the active port. Unit 110 executes a line setting process (step S100 in FIG. 7). In the line setting process in the first transition state (step S100 in FIG. 7), the control unit 110 identifies the physical line P2 as the target physical line (step S110 in FIG. 7), and sets the physical line P4 as another group physical line. It is specified (step S120 in FIG. 7).

  Since the physical line P4 is in the up state (step S120 in FIG. 7: “UP”) and the logical lines L41b and L42c that are the common logical lines are in the forwarding state (step S142 in FIG. 7: “forwarding”), the control is performed. The unit 110 switches the logical lines L21b and L22c set to the physical line P2 from the blocking state based on the ULR blocking to the blocking state based on the group blocking (step S151 in FIG. 7). Regarding the logical line L23z set to the physical line P2, since the common logical line is not set to the physical line P4 (step S141 in FIG. 7: “NO”), the control unit 110 brings the logical line L23z from the blocking state. Switching to the forwarding state (step S152 in FIG. 7).

  In the first transition state, the network path at the time of initialization shown in FIG. 6 is switched to the network path shown in FIG. The network path Ra in the first transition state is the same as in the initial setting of FIG. 6 in that it passes through the two network relay devices 100a and 100b, but the physical line P3 connected to the physical port 13a of the network relay device 100a. It is different in using. The network route Rb in the first transition state is the same as in the initial setting in FIG. The network path Rz in the first transition state is different from the initial setting of FIG. 6 by using the physical line P2 connected to the physical port 12a of the network relay device 100a, thereby three network relay devices 100a, 100c, and 100d. It becomes a route that goes through.

<Second transition state>
FIG. 13 is an explanatory diagram illustrating physical lines and logical lines of the network relay device 100a in the second transition state. FIG. 14 is an explanatory diagram showing the line management database 140 of the network relay device 100a in the second transition state. The second transition state shown in FIG. 13 and FIG. 14 shows a state that has transitioned from the first transition state shown in FIG. 10, FIG. 11 and FIG. 12 in response to the recovery of the physical line P1. The network path in the second transition state is the same as that in the first transition state shown in FIG.

  When the physical line P1 recovers from the failure in the first transition state, the physical line P1 changes from the down state to the up state, and the control unit 110 of the network relay device 100a sets the standby state to set the physical line P1 to the standby port. A port setting process (step S200 in FIG. 8) is executed. In the standby port setting process in the second transition state (step S200 in FIG. 8), the control unit 110 identifies the physical line P1 as the target physical line (step S210 in FIG. 8), and sets the physical line P3 to another group physical line. (Step S220 in FIG. 8).

  The physical line P3 is in the up state (step S220 in FIG. 8: “UP”), and the logical lines L31a and L32c, which are the common logical lines of the logical lines L11a and L12c set in the physical line P1, are in the forwarding state ( The control unit 110 maintains the forwarding state of the logical lines L31a and L32c of the physical line P3 (Step S242 in FIG. 8: “Forwarding”). For the logical line L13z set to the physical line P1, since there is no common logical line in the physical line P3 (step S241: “NO” in FIG. 8), the control unit 110 adds the logical line L13z of the physical line P1. There is no need to change the setting of the physical line P3. Along with the setting related to the physical line P3, the control unit 110 switches the logical lines L11a, L12c, and L13z set to the physical line P1 from the down state to the blocking state by ULR blocking (step S257 in FIG. 8).

<Third transition state>
FIG. 15 is an explanatory diagram showing physical lines and logical lines of the network relay device 100a in the third transition state. FIG. 16 is an explanatory diagram showing the line management database 140 of the network relay device 100a in the third transition state. FIG. 17 is an explanatory diagram showing a network route in the third transition state. The third transition state shown in FIG. 15, FIG. 16 and FIG. 17 shows a state where the transition is made from the second transition state shown in FIG. 13 and FIG.

  When a failure occurs in the physical line P4 in the second transition state, the physical line P4 changes from the up state to the down state, and the control unit 110 of the network relay device 100a executes the physical line down process (step S300 in FIG. 9). To do. In the physical line down process (step S300 in FIG. 9) in the third transition state, the control unit 110 identifies the physical line P4 as a down physical line (step S310 in FIG. 9), and sets the physical line P2 to another group physical line. (Step S320 in FIG. 9).

  The physical line P2 is in the up state (step S320 in FIG. 9: “UP”), and the logical lines L21b and L22c, which are the common logical lines, are in a blocking state due to group blocking (step S343 in FIG. 9: “Group” The control unit 110 switches the logical lines L21b and L22c set for the physical line P2 from the blocking state to the forwarding state (step S355 in FIG. 9). At the same time, the control unit 110 switches the logical lines L41b and L42c set for the physical line P4 from the forwarding state to the down state (step S358 in FIG. 9).

  In the third transition state, the network path in the second transition state, which is the same as the first transition state shown in FIG. 12, is switched to the network path shown in FIG. The network route Ra and the network route Rz in the third transition state are the same as in the second transition state. The network path Rb in the third transition state is similar to the second transition state in that it passes through the two network relay devices 100a and 100c, but uses the physical line P2 connected to the physical port 12a of the network relay device 100a. It is different in point to do.

<4th transition state>
FIG. 18 is an explanatory diagram showing physical lines and logical lines of the network relay device 100a in the fourth transition state. FIG. 19 is an explanatory diagram showing the line management database 140 of the network relay device 100a in the fourth transition state. The fourth transition state shown in FIG. 18 and FIG. 19 shows the state transitioned from the third transition state shown in FIG. 15, FIG. 16, and FIG. 17 according to the recovery of the physical line P4. The network path in the fourth transition state is the same as that in the third transition state shown in FIG.

  When the physical line P4 recovers from the failure in the fourth transition state, the physical line P4 changes from the down state to the up state, and the control unit 110 of the network relay device 100a sets the physical line P4 as a group physical line. A line setting process (step S100 in FIG. 7) is executed. In the line setting process in the fourth transition state (step S100 in FIG. 7), the control unit 110 identifies the physical line P4 as the target physical line (step S110 in FIG. 7), and sets the physical line P2 as another group physical line. It is specified (step S120 in FIG. 7).

  Since the physical line P2 is in the up state (step S120 in FIG. 7: “UP”) and the logical lines L21b and L22c that are the common logical lines are in the forwarding state (step S142 in FIG. 7: “forwarding”), the control is performed. The unit 110 switches the logical lines L41b and L42c set to the physical line P4 from the down state to the blocking state by group blocking (step S151 in FIG. 7).

<5th transition state>
FIG. 20 is an explanatory diagram showing physical lines and logical lines of the network relay device 100a in the fifth transition state. FIG. 21 is an explanatory diagram showing the line management database 140 of the network relay device 100a in the fifth transition state. FIG. 22 is an explanatory diagram showing a network route in the fifth transition state. In the fifth transition state shown in FIGS. 20, 21 and 22, the active port of the uplink redundant is set based on the instruction from the administrator of the network relay device 100a from the fourth transition state shown in FIGS. The state which changed by switching from the physical port 12a to the physical port 11a is shown.

  In order to switch the physical line P1 connected to the physical port 11a in the fourth transition state from the standby port to the active port, the control unit 110 of the network relay device 100a executes line setting processing (step S100 in FIG. 7). In the line setting process in the fifth transition state (step S100 in FIG. 7), the control unit 110 identifies the physical line P1 as the target physical line (step S110 in FIG. 7), and sets the physical line P3 as another group physical line. It is specified (step S120 in FIG. 7).

  Since the physical line P3 is in the up state (step S120 in FIG. 7: “UP”) and the logical lines L31a and L32c that are the common logical lines are in the forwarding state (step S142 in FIG. 7: “forwarding”), the control is performed. The unit 110 switches the logical lines L11a and L12c set to the physical line P1 from the blocking state due to ULR blocking to the blocking state due to group blocking (step S151 in FIG. 7). Regarding the logical line L13z set to the physical line P1, since the common logical line is not set to the physical line P3 (step S141: “NO” in FIG. 7), the control unit 110 brings the logical line L13z from the blocking state. Switching to the forwarding state (step S152 in FIG. 7).

  In order to switch the physical line P2 connected to the physical port 12a in the fourth transition state from the active port to the standby port, the control unit 110 of the network relay device 100a executes standby port setting processing (step S200 in FIG. 8). . In the standby port setting process in the fifth transition state (step S200 in FIG. 8), the control unit 110 identifies the physical line P2 as the target physical line (step S210 in FIG. 8), and sets the physical line P4 to another group physical line. (Step S220 in FIG. 8).

  Since the physical line P4 is in the up state (step S220 in FIG. 8: “UP”), the logical lines L41b and L42c, which are the common logical lines of the logical lines L21b and L22c set in the physical line P2, are in the blocking state ( The control unit 110 switches the logical lines L41b and L42c of the physical line P4 to the forwarding state (step S255 in FIG. 8) (step S242 in FIG. 8: “blocking”). For the logical line L23z set to the physical line P2, since there is no common logical line in the physical line P4 (step S241: “NO” in FIG. 8), the control unit 110 adds the logical line L23z of the physical line P2. There is no need to change the setting of the physical line P4. Along with the setting related to the physical line P4, the control unit 110 switches the logical lines L21b, L22c, and L23z set to the physical line P2 from the forwarding state to the blocking state by ULR blocking (step S257 in FIG. 8).

  In the fifth transition state, the network path in the fourth transition state, which is the same as the third transition state shown in FIG. 17, is switched to the network path shown in FIG. The network route Ra in the fifth transition state is the same as in the fourth transition state. The network path Rb in the fifth transition state is similar to the fourth transition state in that it passes through the two network relay devices 100a and 100c, but uses the physical line P4 connected to the physical port 14a of the network relay device 100a. It is different in point to do. The network route Rz in the fifth transition state uses the physical line P1 connected to the physical port 11a of the network relay device 100a, as in the initial setting state shown in FIG. The route goes through 100a, 100b, and 100d.

<Sixth transition state>
FIG. 23 is an explanatory diagram showing physical lines and logical lines of the network relay device 100a in the sixth transition state. FIG. 24 is an explanatory diagram showing the line management database 140 of the network relay device 100a in the sixth transition state. FIG. 25 is an explanatory diagram of a network route in the sixth transition state. The sixth transition state shown in FIG. 23, FIG. 24, and FIG. 25 is a state that is transitioned from the fifth transition state shown in FIG. 20, FIG. 21, and FIG. Show.

  When a failure occurs in the physical line P1 and the physical line P2 in the fifth transition state, the physical line P1 and the physical line P2 change from the up state to the down state, and the control unit 110 of the network relay device 100a causes the physical line P1 and the physical line P2 to The physical line down process (step S300 in FIG. 9) is executed for each of the lines P2.

  When starting the physical line down process (step S300 in FIG. 9) for the physical line P1, the control unit 110 identifies the physical line P1 as a down physical line (step S310 in FIG. 9), and sets the physical line P3 to another group physical. The line is specified (step S320 in FIG. 9). Since the physical line P3 is in the up state (step S320 in FIG. 9: “UP”), the logical lines L31a and L32c, which are the common logical lines of the logical lines L11a and L12c set in the physical line P1, are in the forwarding state ( Step S342 in FIG. 9: “Forwarding”), the control unit 110 maintains the forwarding state of the logical lines L31a and L32c set to the physical line P3. For the logical line L13z set to the physical line P1, since there is no common logical line in the physical line P3 (step S341: “NO” in FIG. 9), the control unit 110 adds the logical line L13z of the physical line P1. There is no need to change the setting of the physical line P3. Along with the setting related to the physical line P3, the control unit 110 switches the logical lines L11a, L12c, and L13z set to the physical line P1 from the forwarding state to the down state (step S358 in FIG. 9).

  When starting the physical line down process (step S300 in FIG. 9) for the physical line P2, the control unit 110 identifies the physical line P2 as a down physical line (step S310 in FIG. 9), and sets the physical line P4 to another group physical. The line is specified (step S320 in FIG. 9). The physical line P4 is in the up state (step S320 in FIG. 9: “UP”), and the logical lines L41b and L42c, which are common logical lines of the logical lines L21b and L22c set in the physical line P2, are in the forwarding state ( Step S342 in FIG. 9: “Forwarding”), the control unit 110 maintains the forwarding state of the logical lines L41b and L42c set to the physical line P4. Note that, for the logical line L23z set to the physical line P2, since there is no common logical line in the physical line P4 (step S341: “NO” in FIG. 9), the control unit 110 adds the logical line L23z of the physical line P2. There is no need to change the setting of the physical line P4. In conjunction with the setting related to the physical line P3, the control unit 110 switches the logical lines L21b, L22c, and L23z set for the physical line P2 from the blocking state to the down state (step S358 in FIG. 9).

  In the sixth transition state, the network path shown in FIG. 25 is switched from the network path in the fifth transition state shown in FIG. In the sixth transition state, the network route Rz cannot be secured due to the occurrence of multiple failures in the physical line P1 and the physical line P2, but the network route Ra and the network route Rb are maintained in the same manner as in the fifth transition state. .

A3. effect:
According to the network relay device 100 described above, the logical line set in the physical line P1 in the group interface G1 in accordance with the physical line unit redundancy of the physical line P1 and the physical line P2 in the uplink redundant. With respect to the logical line set as the physical line P2 using the physical line P3, redundancy can be implemented for each logical line using the physical line P4 in the group interface G2. Thus, the computer network 10 can be made redundant while setting the logical lines for constructing the logical networks 500a, 500b, and 500c in consideration of the data transfer efficiency of the entire computer network 10.

  In addition, by setting the logical line that forms the logical network 500a, which is inconvenient in terms of data transfer efficiency in the physical line P2 and the physical line P4, to the physical line P3 without setting the physical line P2 and the physical line P4, The computer network 10 can be made redundant while avoiding a decrease in data transfer efficiency.

  Further, by setting the logical line that forms the logical network 500b, which is inconvenient in terms of data transfer efficiency in the physical line P1 and the physical line P3, to the physical line P4 without setting the physical line P1 and the physical line P3, The computer network 10 can be made redundant while avoiding a decrease in data transfer efficiency.

  In addition, even when the other physical line different from the active port in the uplink redundant is recovered from the failure, the active port is maintained as it is (second transition state), so that the active between the two ULR physical lines is maintained. It is possible to suppress frequent port switching and prevent data relay delays associated with active port switching.

  In addition, even when the group physical line in the group interface recovers from a failure, the forwarding state of the logical line is maintained as it is (fourth transition state), so that the forwarding state between the two group physical lines is frequently switched. And delay of data relay due to switching of the forwarding state can be prevented.

B. Other embodiments:
Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and can of course be implemented in various forms without departing from the spirit of the present invention. is there.

  For example, in this embodiment, even when the physical line has recovered from a failure, switching of the active port in uplink redundancy and switching of the forwarding state in the group interface were not performed. When the physical line recovers from a failure, switching of the active port in uplink redundancy or switching of the forwarding state in the group interface may be executed.

  In this embodiment, the physical lines P1, P2, P3, and P4 are each configured as a physical line connected to a single physical port. However, in other embodiments, the physical lines P1, P2, P3, and P4 are configured. At least one of these may be configured as a physical line connected to a plurality of physical ports.

  In this embodiment, the line management database 140 is configured as a single database. However, in other embodiments, the line management database 140 may be configured by a plurality of databases.

DESCRIPTION OF SYMBOLS 10 ... Computer network 11a-15a ... Physical port 11b-15b ... Physical port 11c-15c ... Physical port 11d-14d ... Physical port 11e-14e ... Physical port 100, 100a-100e ... Network relay apparatus 110 ... Control part 120 ... CPU
121 ... Physical line monitoring unit 122 ... Uplink redundancy unit 123 ... Group management unit 130 ... Storage unit 131 ... Control program 132 ... Setting information 140 ... Line management database 141-147 ... Field 150 ... Transfer unit 180 ... Interface unit 200, 200a to 200c ... terminal device 300, 300a, 300b ... server 400 ... wide area network 500, 500a to 500c, 500z ... logical network

Claims (8)

A network relay device that relays communication data in a layer 2 network,
A first physical port connected to the first physical line;
A second physical port connected to the second physical line;
A first redundancy unit configured to make the layer 2 network redundant in units of physical lines by selecting one of the first physical line and the second physical line as a physical line used for communication;
A third physical port connected to the third physical line;
In cooperation with the first redundancy unit, a logical line set for one physical line among logical lines common to both the first physical line and the third physical line is used for communication. A network relay apparatus comprising: a second redundancy unit configured to make the layer 2 network redundant in units of logical lines by selecting a line.   The one of the logical lines set as the first physical line is common to the logical line set as the third physical line and is different from any of the logical lines set as the second physical line. 1. The network relay device according to 1.   The first redundancy unit maintains the selection of the one physical line even when the other physical line different from the one used in communication recovers from a failure. The network relay device according to claim 2.   The second redundancy unit maintains selection of the one logical line even when the other logical line different from the one logical line currently used for communication recovers from a failure. The network relay device according to claim 3. The network relay device according to any one of claims 1 to 4, further comprising:
A fourth physical port connected to the fourth physical line;
In cooperation with the first redundancy unit, a logical line set for one physical line among logical lines common to both the second physical line and the fourth physical line is used for communication. And a third redundancy unit that makes the layer 2 network redundant in units of logical lines by selecting a line.   One of the logical lines set as the first physical line is common to the logical line set as the third physical line, and any one of the logical lines set as the second physical line and the fourth physical line, respectively. The network relay device according to claim 5, which is different from the network relay device.   The third redundancy unit maintains the selection of the one logical line even when the other logical line different from the one logical line being used for communication recovers from a failure. The network relay device according to claim 6. A network relay method for relaying communication data in a layer 2 network,
Set logical lines for the first physical line and the second physical line,
Selecting one of the first physical line and the second physical line as a physical line used for communication, thereby performing a first redundancy for making the layer 2 network redundant in units of physical lines;
A logical line common to the first physical line is set as the third physical line,
Along with the first redundancy, a logical line set as one physical line among logical lines common to both the first physical line and the third physical line is selected as a logical line used for communication. A network relay method that executes second redundancy for making the layer 2 network redundant in units of logical lines.

Images