JP5533100B2 - Switch, notification program, and notification method - Google Patents

Description

  The present invention relates to a switch for notifying address change, a notification program, and a notification method.

  When there are a plurality of routes between a plurality of switches, when a switch detects the occurrence of a failure and switches the route, the switch is notified to the surrounding switches, and each switch has a MAC (Media Access Control) address learning table. It needs to be rewritten. When the path is switched by the spanning tree protocol, there is a problem that it takes time to resume communication. As an improvement technique, Japanese Patent Application Laid-Open No. 2004-151620 discloses a method of notifying each switch by a predetermined dedicated packet, or sending a dummy multicast packet so that each switch that receives and forwards the packet learns the MAC address. A method is disclosed.

US Patent Application Publication No. 2008/0123561

  However, the method using a dedicated packet has a problem in that the cost increases because the receiving side needs the corresponding function. Further, in the method using dummy multicast packets, there is a problem in that even a terminal that does not need to change the MAC address learning table on the network is received, and the load on the terminal increases due to an originally unnecessary reception process.

  An object of the present invention is to provide a switch, a notification program, and a notification method that can reduce the reception load of a terminal with a simple configuration in order to eliminate the above-described problems caused by the related art.

  In order to solve the above-described problems and achieve the object, the present switch, the notification program, and the notification method detect a port connected to a failure occurrence path and refer to the MAC address learning table to detect the detected port. It is a requirement to set a unicast packet having the MAC address of the information processing apparatus corresponding to another port other than the source as the transmission source and the unused MAC address as the destination, and transmitting the set unicast packet.

  According to the switch, the notification program, and the notification method, there is an effect that the reception load of the terminal can be reduced with a simple configuration.

It is explanatory drawing which shows the structure of a MAC address. It is a block diagram which shows an example of the hardware constitutions of a switch. It is a block diagram which shows the functional structural example of the switch concerning this embodiment. It is explanatory drawing (the 1) which shows the example 1 of a MAC address change notification. It is explanatory drawing (the 2) which shows the MAC address change notification example 1. It is explanatory drawing (the 3) which shows the example 1 of a MAC address change notification. It is explanatory drawing (the 4) which shows the MAC address change notification example 1. It is explanatory drawing (the 1) which shows the example 2 of a MAC address change notification. It is explanatory drawing (the 2) which shows the MAC address change notification example 2. It is explanatory drawing (the 3) which shows the MAC address change notification example 2. It is explanatory drawing (the 4) which shows the MAC address change notification example 2. It is a flowchart which shows an address change notification process procedure. It is a flowchart which shows a MAC address change process sequence. It is explanatory drawing (the 1) which shows the example 3 of a MAC address change notification. It is explanatory drawing (the 2) which shows the example 3 of a MAC address change notification. It is a flowchart (the 1) which shows the MAC address change notification process procedure in the address change notification example 3. It is a flowchart (the 2) which shows the MAC address change notification process sequence in the address change notification example 3.

  Exemplary embodiments of a switch, a notification program, and a notification method according to the present invention will be described below in detail with reference to the accompanying drawings.

  In the present embodiment, when a failure is detected in the active system, the change of the MAC address is notified by delivering an unknown unknown unicast packet instead of a dummy multicast packet. As the destination MAC address of the unknown unicast packet, a MAC address that is not used in the network, such as a specific local address (a MAC address with a local bit set) is used.

  In the case of an unknown unicast packet, only the switch that needs to change the MAC address learning processes it, so that it is not received by the terminals under the switch and the terminal is not loaded. Since the unknown unicast packet is transferred to all the ports of the switch, it has the same effect as when the multicast packet is used for the switch.

(MAC address structure)
FIG. 1 is an explanatory diagram showing the structure of a MAC address. As shown in (A) to (C), the MAC address is composed of a manufacturer code of upper 3 bytes and a product number of lower 3 bytes. The manufacturer code is a code for identifying the manufacturer of the device to which the MAC address is assigned.

  The first 1 bit of the manufacturer code represents an I / G (Individual / Group) bit. If it is 0, it indicates an individual address (unicast), and if it is 1, it indicates a group address (multicast). The second bit from the head represents a U / L (Universal / Local) bit. If it is 0, it indicates a global address, and if it is 1, it indicates a local address.

  In the unknown unicast packet used in this embodiment, the I / G bit is set to 0 as shown in (B) and (C). A packet having a MAC address with the I / G bit set to 0 is a unicast packet.

  (B) shows the MAC address with the U / L bit set to 0. When the U / L bit is 0, the manufacturer is specified by the remaining 22 bits of the manufacturer code. Therefore, in the unknown unicast packet in this case, the product number represented by the lower 3 bytes is set to a code (unused MAC address) that is not assigned to any of the products manufactured by the manufacturer. .

  Further, (C) indicates a MAC address in which the U / L bit is set to 1. When the U / L bit is 1, the remaining 46 bits represent a unique address in a specific network. Therefore, in the unknown unicast packet in this case, the address expressed by the remaining 46 bits is set to an unused MAC address that is not assigned to anyone in the specific network.

(Switch hardware configuration)
FIG. 2 is a block diagram illustrating an example of a hardware configuration of the switch. The switch S includes a processor 201, a memory 202, a selection circuit 203, and a plurality of ports P. The processor 201 performs overall control of the switch. The memory 202 is used as a work area for the processor 201.

  The memory 202 stores a MAC address learning table T, a VLAN table VL, a program 205, and an unused MAC address 206. The selection circuit 203 selects a port for transferring a packet in response to a command from the processor 201. For example, the ports P are connected according to the setting of the VLAN table VL. Port P transmits and receives packets.

(Functional configuration of the switch)
FIG. 3 is a block diagram illustrating a functional configuration example of the switch according to the present embodiment. The switch S includes a storage unit 300, a reception unit 301, a detection unit 302, a setting unit 303, and a transmission unit 304. The storage unit 300 has a function of storing various information. Specifically, the MAC address learning table T, the VLAN table VL, the program 205, and the unused MAC address 206 shown in FIG. The storage unit 300 realizes its function by the memory 202 shown in FIG.

  The receiving unit 301 has a function of receiving a packet from a connection destination. Specifically, if the connection destination is the switch S, the packet transferred from the switch S is received. Further, if the connection destination is a terminal (personal computer or server), a packet transmitted from the terminal is received. The receiving unit 301 realizes its function by the port P shown in FIG.

  The detection unit 302 has a function of detecting a failure of the active link connected to the port P. Specifically, for example, when a failure occurs, the voltage level of the active system link drops from the normal voltage value, and therefore, by monitoring the voltage value, the active system link connected to the port P Detect whether a failure has occurred. Specifically, the detection unit 302 realizes its function by, for example, monitoring the voltage signal obtained from the port P shown in FIG. 2 with the program 205 stored in the memory 202.

  The setting unit 303 has a function of performing various settings. Specifically, the MAC address learning table T is set, the VLAN table VL is set, and the connection between the ports P is set by the selection circuit 203 as in the conventional case. Further, when the detection unit 302 detects a failure of the active link, the standby link is set from link down to link up.

  In the present embodiment, the unused MAC address 206 is further read from the storage unit 300, and an unknown unicast packet with the read unused MAC address as a destination is generated. In this case, the transmission source of the unknown unicast packet is, for example, as follows.

(1) When the VLAN is not set, in the MAC address learning table T, the MAC address corresponding to a port other than the port connected to the failed link (hereinafter referred to as “connection source port”)

(2) In the above (1), the MAC address corresponding to the designated port among the ports other than the connection source port

(3) In the above (1), the designated MAC address in the MAC address corresponding to a port other than the connection source port

(4) When VLAN is set, in the MAC address learning table T, the MAC address corresponding to the port belonging to the same VLAN as the connection source port among the ports other than the connection source port

(5) In the above (4), the MAC address corresponding to the designated port among the ports belonging to the same VLAN as the connection source port among the ports other than the connection source port

(6) In the above (4), the designated MAC address in the MAC address corresponding to the port belonging to the same VLAN as the connection source port among the ports other than the connection source port

  The designated port and the designated MAC address are set in advance and stored in the storage unit 300.

  In the above (1) to (6), when there are a plurality of source MAC addresses, an unknown unicast packet is generated for the number of MAC addresses. However, by setting the designated port and the designated MAC address in (2), (3), (5), and (6), the number of source MAC addresses can be reduced. As a result, the number of generated unicast unicast packets is reduced, so that the MAC address change can be notified early.

  The transmission unit 304 has a function of transmitting a packet to a transfer destination. Specifically, if the transfer destination is the switch S, the transmitted packet is transmitted to the transfer destination switch. If the transfer destination is an information processing apparatus (terminal or server), the transmitted packet is transmitted to the transfer destination. The transmission unit 304 realizes its function by the port P shown in FIG. Next, a specific example of the MAC address change notification will be described with reference to FIGS.

(MAC address change notification example 1)
4 to 7 are explanatory diagrams showing MAC address change notification example 1. FIG. Specific example 1 of the MAC address change notification indicates a MAC address change notification in a network in which no VLAN is set or in the same VLAN.

  4 to 7, Sa to Sd are switches, and Ca1, Ca2, and Cd are terminals. Lxy (x and y are arbitrary alphabets) represents a link between the switches Sx to Sy. For example, the link Lab is a link between the switches Sa to Sb.

  4 to 7, numbers described around the figures of the switches Sa and Sd are port numbers. Further, Ta represents the MAC address learning table of the switch Sa, and Td represents the MAC address learning table of the switch Sd. The MAC address learning table is a table in which port numbers are associated with MAC addresses. For example, the first record of the MAC address learning table Ta indicates that the port 1 corresponds to the MAC address of the terminal Cd.

  In addition, the paths of the switches Sa, Sb, and Sd (links Lab and Lbd) are set as active paths, and the paths of the switches Sa, Sc, and Sd (links Lac and Lcd) are set as standby paths. Therefore, normally, packets are communicated using the active route, but when a failure occurs on the active route, the packet is switched to the standby route. For example, when a failure occurs in the link Lab, the standby path is linked up so that communication is possible.

  In FIG. 4, the packet from the terminal Ca1 destined for the terminal Cd is received at the port 3 of the switch Sa. Then, in the switch Sa, by referring to the MAC address learning table Ta, transfer is performed from the port 1 corresponding to the MAC address of the destination terminal Cd. The transferred packet is received by the port 1 of the switch Sd via the link Lab, the switch Sb, and the link Lbd. In the switch Sd, by referring to the MAC address learning table Td, the transfer is performed from the port 3 corresponding to the MAC address of the destination terminal Cd. Thereby, the packet of the terminal Ca1 reaches the terminal Cd.

  In FIG. 5, when a failure occurs in the link Lab, the detection unit 302 of the switch Sa detects the failure occurrence. As a result, the setting unit 303 links the port 2 of the switch Sa so that the switches Sa to Sc can communicate with each other. The link Lcd between the switches Sc to Sd may be always in the link up state, and the setting is changed from the link down state to the link up state when the switch Sa to Sc is in the link up state. It is also possible.

  Further, when the switch Sa detects the occurrence of a failure in the link Lab, the switch Sa deletes the MAC address (the MAC address of the terminal Cd) corresponding to the connection source port 1 connected to the link Lab from the MAC address learning table Ta. . This prevents erroneous transfer to the active route.

  Next, in FIG. 6, the switch Sa uses the setting unit 303 to generate unknown unicast packets UP1 and UP2. In the unknown unicast packets UP1 and UP2, the MAC addresses learned in the MAC address learning table Ta among the ports 2 to 4 other than the port 1 that is the connection source port (in FIG. Ca2 MAC address). The destination is an unused MAC address (indicated as “unknown” in FIG. 6) stored in the storage unit 300 (memory 202).

  In FIG. 7, the switch Sa transmits unknown unicast packets UP 1 and UP 2 from the port 2. The transmitted unknown unicast packets UP1 and UP2 are transferred to the switches Sc and Sd via the standby path. In the switch Sd, the data is also transferred to the switch Sb via the link Lbd in the link-up state.

  In the switch Sd, when the unknown unicast packet UP1 is received from the port 2 in the MAC address learning table Td, the MAC address of the terminal Ca1 that is the transmission source address of the unknown unicast packet UP1 is used as the MAC address corresponding to the port 2. Is written in the MAC address learning table Td. Then, the MAC address of the terminal Ca1 corresponding to the port 1 is deleted from the MAC address learning table Td.

  Similarly, when the unknown unicast packet UP2 is received from the port 2 in the MAC address learning table Td, the MAC address of the terminal Ca2 that is the transmission source address of the unknown unicast packet UP2 is used as the MAC address corresponding to the port 2. Write to the MAC address learning table Td. Then, the MAC address of the terminal Ca2 corresponding to the port 1 is deleted from the MAC address learning table Td.

  Thus, although the unknown unicast packets UP1 and UP2 are transferred to the switches Sb to Sd, since the destination is an unused MAC address, the terminals Ca1, Ca2 and Cd do not match and cannot be received.

  As described above, the switches Sb to Sd in the target network are notified to the switch Sd that needs to change the address in the same manner as multicast, and the MAC address learning table Td is updated as usual in the switch Sd. On the other hand, the unknown unicast packets UP1 and UP2 are not received by the terminals Ca1, Ca2 and Cd, so that the reception load can be reduced.

(MAC address change notification example 2)
8 to 11 are explanatory diagrams illustrating MAC address change notification example 2. FIG. Specific example 2 of the MAC address change notification shows the MAC address change notification when a plurality of VLANs (two in FIG. 8 to FIG. 11) are set. 8 to 11, Sa to Se are switches, and Ca1, Ca2, Cd, and Ce are terminals. Lxy (x and y are arbitrary alphabets) represents a link between the switches Sx to Sy. For example, the link Lab is a link between the switches Sa to Sb.

  8 to 11, the numbers described around the figures of the switches Sa and Sd are port numbers. Further, Ta represents the MAC address learning table of the switch Sa, and Td represents the MAC address learning table of the switch Sd. The MAC address learning table Ta is a table in which port numbers are associated with MAC addresses. For example, the first record of the MAC address learning table Ta indicates that the port 1 corresponds to the MAC address of the terminal Cd.

  VLa is a VLAN table held by the switch Sa. 8 to 11, the terminals Ca1 and Cd, the ports 1 to 3 of the switch Sa, and the switches Sb to Sd belong to the VLAN 1, and the terminals Ca2, Ce and the ports 4, 5, and the switch Se of the switch Sa are assigned to the VLAN 2. Assume that you belong.

  In the VLAN 1, the paths of the switches Sa, Sb, and Sd (links Lab and Lbd) are used as active paths, and the paths of the switches Sa, Sc, and Sd (links Lac and Lcd) are used as standby paths. Therefore, normally, packets are communicated using the active route, but when a failure occurs on the active route, the packet is switched to the standby route. For example, when a failure occurs in the link Lab, the standby path is linked up so that communication is possible.

  In FIG. 8, the packet from the terminal Ca1 destined for the terminal Cd is received by the port 3 of the switch Sa. Then, in the switch Sa, by referring to the MAC address learning table Ta, transfer is performed from the port 1 corresponding to the MAC address of the destination terminal Cd. The transferred packet is received by the port 1 of the switch Sd via the link Lab, the switch Sb, and the link Lbd. In the switch Sd, by referring to the MAC address learning table Td, the transfer is performed from the port 3 corresponding to the MAC address of the destination terminal Cd. Thereby, the packet of the terminal Ca1 reaches the terminal Cd.

  In FIG. 9, when a failure occurs in the link Lab, the detection unit 302 of the switch Sa detects the failure occurrence. As a result, the setting unit 303 links the port 2 of the switch Sa so that the switches Sa to Sc can communicate with each other. The link Lcd between the switches Sc to Sd may be always in the link up state, and the setting is changed from the link down state to the link up state when the switch Sa to Sc is in the link up state. It is good as well.

  Further, when the switch Sa detects the occurrence of a failure in the link Lab, the switch Sa deletes the MAC address (the MAC address of the terminal Cd) corresponding to the connection source port 1 connected to the link Lab from the MAC address learning table Ta. . This prevents erroneous transfer to the path that was the active system.

  Next, in FIG. 10, the switch Sa uses the setting unit 303 to generate an unknown unicast packet UP1. The unknown unicast packet UP1 has a MAC address corresponding to the port 3 that is the same VLAN (VLAN1) as the port 1 among the ports 2 to 5 other than the port 1 that is the connection source port (in FIG. 10, MAC address of terminal Ca1). The destination is assumed to be an unused MAC address (indicated as “unknown” in FIG. 10) stored in the storage unit 300 (memory 202).

  In FIG. 11, the switch Sa transmits an unknown unicast packet UP1 from the port 2. Since port 5 is a different VLAN 2, it is not transmitted from port 5. The transmitted unknown unicast packet UP1 is transferred to the switches Sc and Sd via the standby path. In the switch Sd, the data is also transferred to the switch Sb via the link Lbd in the link-up state.

  In the switch Sd, when the unknown unicast packet UP1 is received from the port 2 in the MAC address learning table Td, the MAC address of the terminal Ca1 that is the transmission source address of the unknown unicast packet UP1 is used as the MAC address corresponding to the port 2. Is written in the MAC address learning table Td. Then, the MAC address of the terminal Ca1 corresponding to the port 1 is deleted from the MAC address learning table Td.

  Thus, although the unknown unicast packet UP1 is transferred to the switches Sb to Sd, since the destination is an unused MAC address, the terminals Ca1, Ca2, and Cd do not match the MAC addresses and cannot be received.

  In this manner, the switches Sb to Sd in the target VLAN 1 are distributed in the same manner as multicast, and the MAC address learning table Td is updated in the switch Sd as usual. On the other hand, since the unknown unicast packet UP1 is not received by the terminals Ca1, Ca2, and Cd, the reception load can be reduced.

  In addition, since an unknown unicast packet is not generated for a port belonging to VLAN 2 that is different from port 1 that is a connection source port, the number of unknown unicast packets can be reduced.

(Address change notification processing procedure)
FIG. 12 is a flowchart showing the address change notification processing procedure. The flowchart shown in FIG. 12 is executed by the switch Sa in the examples of FIGS.

  First, the switch S waits for detection of the occurrence of a failure in the active system path by the detection unit 302 (step S1201: No). When the occurrence of a failure is detected (step S1201: Yes), the switch S causes the setting unit 303 to switch the standby port (the port connected to the standby link. In the MAC address change notification examples 1 and 2, the port 2 ) Is set to an operable state (step S1202).

  Then, the switch S deletes the MAC address corresponding to the active port from the MAC address learning table T (step S1203). In MAC address change notification examples 1 and 2, the MAC address of the terminal Cd corresponding to port 1 of the MAC address learning table Ta is deleted from the MAC address learning table Ta.

  Then, the switch S determines whether or not there is another VLAN (in the MAC address change notification example 2, VLAN 2 different from VLAN 1 to which the port 1 that is the connection source port belongs) (step S1204). When there is no other VLAN (step S1204: No), the switch S extracts a MAC address of a port other than the connection source port from the MAC address learning table T (step S1205), and proceeds to step S1207.

  On the other hand, when there is another VLAN (step S1204: Yes), the switch S extracts from the MAC address learning table T the MAC address of the port other than the connection source port and in the same VLAN as the connection source port (step S1204). S1206), the process proceeds to step S1207.

  In step S1207, the switch S uses the setting unit 303 to generate an unknown unicast packet having the extracted MAC address in step S1205 or S1206 as the transmission source and the unused MAC address as the destination (step S1207). Then, the switch S causes the transmission unit 304 to transmit the generated unknown unicast packet from a port other than the connection source port (step S1208). Thereby, a series of processes of the MAC address change notification process is completed.

(MAC address change processing)
FIG. 13 is a flowchart showing a procedure for changing the MAC address. The flowchart of FIG. 13 is a procedure executed by a switch that has received an unknown unicast packet.

  First, the switch S waits for reception of an unknown unicast packet (step S1301: No). When receiving the unknown unicast packet (step S1301: Yes), the switch S uses the MAC address learning table T as the MAC address corresponding to the receiving port of the unknown unicast packet, with the source MAC address of the unknown unicast packet. Registration is performed (step S1302).

  Then, the switch S deletes the transmission source MAC address from the port in which the transmission source MAC address is registered in the MAC address learning table T (step S1302). Thereafter, the switch S transfers the unknown unicast packet from a port other than the receiving port of the unknown unicast packet (step S1304).

  Thus, according to the address change notification described above, the destination MAC address of the unknown unicast packet is a MAC address that is not used by any terminal. Therefore, the switch S that has received the unknown unicast packet determines that it is an unlearned MAC address and transfers it from all ports other than the reception port of the unknown unicast packet. Further, it is possible to learn by registering the transmission source MAC address of the unknown unicast packet as the MAC address corresponding to the reception port.

  On the other hand, since it is determined that none of the terminals is a packet addressed to the own terminal, reception processing such as a multicast packet is not performed at the terminal. As a result, the processing load on the terminal that receives and processes unnecessary multicast packets can be reduced, and adverse effects such as the slow operation of applications in the terminal can be prevented.

(MAC address change notification example 3)
14 and 15 are explanatory diagrams showing MAC address change notification example 3. FIG. In the MAC address change notification example 1 shown in FIG. 4 to FIG. 7, the unknown unicast packet UP1 with the MAC addresses of the terminals Ca1 and Ca2 under the switch Sa as the source MAC address and the unused MAC address as the destination MAC address. , UP2 was sent. On the other hand, the MAC address change notification example 3 is an example in which an unknown unicast packet having the MAC address corresponding to the designated port or the designated MAC address as the transmission source MAC address is transmitted.

  In MAC address change notification example 1, unknown unicast packets for the number of terminals under the switch Sa are generated and transmitted. However, in MAC address change notification example 3, the number of unknown unicast packets generated is reduced. Become.

  Thus, for example, when the designated MAC address is the MAC address of the terminal Ca1, the following two cases are assumed as usage scenes limited to a specific MAC address. First, since communication between the terminal Ca2 and the terminal Cd always starts from the terminal Ca2, there may be a case where learning using the unknown unicast packet is unnecessary for the terminal Ca2. The other case is considered that there is no need to rush in time for communication between the terminal Ca2 and the terminal Cd, and there is no problem even with recovery after aging out.

  Since MAC address change notification example 3 has the same contents as MAC address change notification example 1 up to FIGS. 4 and 5, the subsequent steps will be described with reference to FIGS. 14 and 15.

  In FIG. 14, the switch Sa generates an unknown unicast packet UP1. As in the MAC address change notification example 1, the unknown unicast packet UP2 is not generated. Specifically, by setting the designated port as port 3, only the unknown unicast packet UP1 with the MAC address of the terminal Ca1 corresponding to the designated port 3 among the ports 3 and 4 as the source MAC address is generated. Is done.

  Further, by setting a designated MAC address (in this case, the MAC address of the terminal Ca1) instead of a port designation, an unknown unicast packet UP1 with the MAC address of the terminal Ca1 as the designated MAC address as the transmission source MAC address. Only is generated.

  In FIG. 15, the switch Sa transmits an unknown unicast packet UP1. The transmitted unknown unicast packet UP1 is transferred to the switches Sc and Sd via the standby path. In the switch Sd, the data is also transferred to the switch Sb via the link Lbd in the link-up state.

  In the switch Sd, when the unknown unicast packet UP1 is received from the port 2 in the MAC address learning table Td, the MAC address of the terminal Ca1 that is the transmission source address of the unknown unicast packet UP1 is used as the MAC address corresponding to the port 2. Is written in the MAC address learning table Td. Then, the MAC address of the terminal Ca1 corresponding to the port 1 is deleted from the MAC address learning table Td. The MAC address of the terminal Ca2 is not erased.

  In MAC address change notification example 3, the unknown unicast packet UP1 is transferred to the switches Sb to Sd, but since the destination is an unused MAC address, the MAC addresses do not match at the terminals Ca1, Ca2, and Cd. Can not.

  As described above, the switches Sb to Sd in the target network are notified to the switch Sd that needs to change the address in the same manner as multicast, and the MAC address learning table Td is updated as usual in the switch Sd. On the other hand, since the unknown unicast packet UP1 is not received by the terminals Ca1, Ca2, and Cd, the reception load can be reduced.

  In the stage of FIG. 15, the MAC address of the terminal Ca2 remains in the port 1 in the MAC address learning table Td of the switch Sd. However, when a packet destined for the MAC address of the terminal Cd is transmitted from the terminal Ca1 thereafter, the packet is received from the port 2 of the switch Sd. 2 has no problem because the MAC address of the terminal Ca2 is learned.

  In addition, since the MAC address of the terminal Ca2 corresponding to the port 1 is deleted from the MAC address learning table Td by being aged out, there is no problem. Age-out is a mechanism for erasing the MAC address of a device without communication from the MAC address learning table. Specifically, a MAC address holding time is set for each port in the MAC address learning table T, and an erasing operation is executed for a port for which a packet from the MAC address has not been received within the holding time.

  In the case of FIG. 15, due to the failure of the link Lab, a packet whose source MAC address is the MAC address of Ca2 is not received from the port 1 of the switch Sd. Therefore, the MAC address of the terminal Ca1 corresponding to the port 1 is deleted from the MAC address learning table Td of the switch Sd.

  When the MAC address of the terminal Ca1 corresponding to the port 1 is deleted from the MAC address learning table Td, the MAC address of the terminal Ca2 is in an unknown state, so that a packet addressed to the terminal Ca2 is received from the terminal Cd by the switch Sd. In such a case, flooding is performed on all the ports of the switch Sd. By this flooding, the packet transmitted from the port 2 of the switch Sd reaches the terminal Ca2, and the response packet from the terminal Ca2 passes through the port 2 of the switch Sd, so that the MAC address of the terminal Ca2 becomes the correct port (port 2). Will be learned.

  FIGS. 16 and 17 are flowcharts showing the MAC address change notification processing procedure in the address change notification example 3. FIG. 16 shows the MAC address change notification process in which the designated port is preset, and FIG. 17 shows the MAC address change notice process in which the designated MAC address is preset. 16 and 17, the same steps as those in FIG. 12 are denoted by the same step numbers, and the description thereof is omitted.

  In FIG. 16, when there is no other VLAN in step S1204 (step S1204: No), the switch S extracts the MAC address of the designated port other than the connection source port from the MAC address learning table T (step S1605), and step S1207. Migrate to

  On the other hand, when there is another VLAN (step S1204: Yes), the switch S extracts the MAC address of the designated port other than the connection source port and in the same VLAN as the connection source port from the MAC address learning table T ( Step S1606) and the process proceeds to Step S1207.

  In FIG. 17, when there is no other VLAN in step S1204 (step S1204: No), the switch S extracts a designated MAC address other than the connection source port from the MAC address learning table (step S1705), and the process proceeds to step S1207. Transition.

  On the other hand, when there is another VLAN (step S1204: Yes), the switch S extracts a designated MAC address other than the connection source port and in the same VLAN as the connection source port from the MAC address learning table (step S1706). The process proceeds to step S1207.

  From the above, according to the present embodiment, the destination MAC address of the unknown unicast packet is a MAC address that is not used by any terminal. Therefore, the switch S that has received the unknown unicast packet determines that it is an unlearned MAC address and transfers it from all ports other than the reception port of the unknown unicast packet. Further, it is possible to learn by registering the transmission source MAC address of the unknown unicast packet as the MAC address corresponding to the reception port.

  On the other hand, since it is determined that none of the terminals is a packet addressed to the own terminal, reception processing such as a multicast packet is not performed at the terminal. As a result, the processing load on the terminal that receives and processes unnecessary multicast packets can be reduced, and adverse effects such as the slow operation of applications in the terminal can be prevented.

  In addition, when the VLAN is set, the unknown unicast packet is not transmitted to the other VLAN, so that the reception load of the switch in the other VLAN is reduced. Further, in other VLANs, learning of the MAC address learning table using an unknown unicast packet is unnecessary, so that useless learning can be prevented.

  Furthermore, by specifying a port and MAC address, it is not necessary to generate and transmit an unknown unicast packet for a MAC address that does not require early learning. Accordingly, since the number of unknown unicast packets generated is reduced, it is possible to notify the MAC address change at an early stage.

T MAC address learning table VL VLAN table S switch 300 storage unit 301 reception unit 302 detection unit 303 setting unit 304 transmission unit

Claims (7)

Detection means for detecting a port connected to the failure occurrence path;
Referring to the MAC address learning table, information indicating that the MAC address of the information processing apparatus corresponding to another port other than the port detected by the detection unit is a transmission source and is a unicast address is set. Setting means for setting a unicast packet destined for the MAC address in use;
Transmitting means for transmitting a unicast packet set by the setting means;
A switch comprising: The setting means includes
A unicast packet having a MAC address of an information processing apparatus corresponding to a port in the same VLAN as the detected port among the other ports as a source and an unused MAC address as a destination is set. The switch according to claim 1. The setting means includes
The switch according to claim 1 or 2, wherein a unicast packet having a MAC address of an information processing apparatus corresponding to a designated port among the other ports as a transmission source and a non-use MAC address as a destination is set. . The setting means includes
The unicast packet having a designated MAC address as a transmission source and a non-use MAC address as a destination among the MAC addresses of the information processing devices corresponding to the other ports is set. switch. The setting means includes
The switch according to claim 1, wherein a MAC address corresponding to the detected port is deleted from the MAC address learning table. A detection step of detecting a port connected to the failure occurrence path;
Referring to the MAC address learning table, information indicating that the MAC address of the information processing device corresponding to another port other than the port detected by the detection step is a transmission source and is a unicast address is set. A setting step for setting a unicast packet destined for the used MAC address;
A transmission step of transmitting the unicast packet set by the setting step;
A notification program for causing a computer to execute A detection step of detecting a port connected to the failure occurrence path;
Referring to the MAC address learning table, information indicating that the MAC address of the information processing device corresponding to another port other than the port detected by the detection step is a transmission source and is a unicast address is set. A setting step for setting a unicast packet destined for the used MAC address;
A transmission step of transmitting the unicast packet set by the setting step;
The notification method characterized by including.

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