Backup method for network device connected to network and network device designed therefor

Abstract

The present invention relates to: a backup method for a network device connected to a network; and a network device designed for this purpose. In the method, network devices (1, 2, 3) connected to a network (10) are designed to use a neighbor detection protocol and can send their own device information to neighboring network devices connected to the network and designed to use the neighbor detection protocol according to a network topology for the network, and may receive device information from neighboring network devices connected to the network and designed to use the neighbor detection protocol according to a network topology. After two adjacent network devices (1, 2, 3) designed to use the neighbor detection protocol are turned on, at least a first network device of the two network devices (1) having its own first device information sends the first device information to a second network device of the two network devices (2), and storing the information in a second network device in a manner associated with the transmitting network device, in which if the first network device is replaced with a replacement network device, the replacement network device is switched on after the replacement network device is switched on, and the information is stored in the second network device in a manner associated with the transmitting network device. The replacement network device requests transmission of the stored first device information from the second network device.

Description

Technical Field

[0001] The present invention relates to a backup method for a network device connected to a network and a network device provided therefor. Background Art

[0002] As is known, in a network topology, in particular a bus topology, a corresponding network device connected to the network in a manner adjacent to a network device connected to the network as a subscriber can be clearly identified as another subscriber, which is also called neighbor discovery. This requires that only one other network device (point-to-point) is connected to the port (physical connection point) of the network device.

[0003] In Ethernet-based networks for industrial communication, for example, LLDP (Link Layer Discovery Protocol) is used for neighbor discovery. Using this topology discovery, configurations stored in control units (also called "controller devices" in English) can be redistributed after a device replacement, for example (see e.g. ProfiNet). In addition to the controller unit, this system also requires a unique identification such as an ID, order code or similar, so that the corresponding device type or the corresponding class of network devices can be clearly identified. Summary of the invention

[0004] In a network topology in which respective network devices connected to the network in a manner adjacent to the network devices can be uniquely identified, the object of the present invention is to demonstrate an alternative method for retaining device information, in particular type and / or configuration data, assigned to the network devices and making this information available again, in particular when the network devices are replaced.

[0005] According to the invention, the object is achieved in particular by a method and a network device having the features according to the independent claims, wherein the respective dependent claims each include preferred further embodiments. The invention is further achieved by a computer program comprising program code means for performing the method and a computer-readable medium comprising instructions which, when executed on at least one computer, cause at least one computer to perform the steps of the method.

[0006] Specifically, a network device is proposed, which uses a neighbor discovery protocol and is configured to send its own device information to a network device connected to the network in an adjacent manner according to the network topology for the network after being connected to the network, and is configured to use the neighbor discovery protocol and receive device information from a network device connected to the network in an adjacent manner and configured to use the neighbor discovery protocol according to the network topology. According to the solution of the present invention, it is further provided that the network device is now further configured to, after being connected to the network and after receiving device information from a network device connected to the network in an adjacent manner, store the information assigned to the network device, and request its own device information from another network device connected to the network in an adjacent manner.

[0007] Specifically, a backup method for network devices connected to a network and configured to use a neighbor discovery protocol is further proposed, wherein each of these network devices connected to the network and configured to use the protocol is configured to use the protocol to send its own device information to a network device connected to the network in an adjacent manner and configured to use the neighbor discovery protocol according to a network topology for the network, and receive device information from a network device connected to the network in an adjacent manner and configured to use the neighbor discovery protocol according to the network topology, wherein after two network devices connected to each other in an adjacent manner and configured to use the neighbor discovery protocol have been turned on, at least a first network device of the two network devices having its own first device information sends the first device information to a second network device of the two network devices, and the first device information is stored in a second network device assigned to the sending network device, wherein in a case where the first network device is replaced by a replacement network device and after the replacement network device has been turned on, the replacement network device requests that the stored first device information be sent from the second network device.

[0008] Therefore, a significant advantage of the solution according to the present invention is that a network device is designated as a "controller" or "monitor" of at least one network device connected to the network in an adjacent manner, so that after the network device is replaced, the device information previously assigned to the replaced network device, in particular information related to a specific configuration, can also be restored for the replacement device in the simplest manner, in particular in a decentralized manner.

[0009] The process according to the present invention can be implemented with pure software or pure hardware, or can also be implemented by a combination of suitable hardware and software. Additionally or alternatively, a separate functional unit can be set in the network device for the process according to the present invention. Therefore, the facilities according to the present invention of the network device suitable for this purpose can also be implemented with pure software or pure hardware, or can also be provided by a combination of suitable hardware and software, and additionally or alternatively, a separate functional unit can be set in the network device for the facilities according to the present invention of the network device suitable for this purpose. For example, the separate functional unit can also be run as software on hardware already existing in the network device, and the existing hardware is, for example, an existing processor. However, hardware can also be provided specifically for the separate functional unit.

[0010] Furthermore, the present invention therefore also particularly relates to a computer program comprising program code means for executing the steps of the method according to the invention. Finally, the present invention therefore also particularly relates to a computer-readable medium comprising instructions which, when executed on at least one computer, cause the at least one computer to execute the steps of the method according to the invention. Such a medium may also be, for example, a CD-ROM or a DVD or a USB or a flash memory. It should also be noted that a computer-readable medium is not to be understood only as a physical medium, but may also be present, for example, in the form of a data stream and / or a signal representing a data stream.

[0011] The object of the present invention is therefore particularly applicable to network topologies based on daisy-chain (point-to-point, P2P) wiring, in which each network device has at least one unique neighbor. From the perspective of the network device, the direct neighbor is therefore able to record the device information of this network device, in particular including its configuration data set, as an "unknown" data set, thereby storing it in a decentralized manner. Therefore, such a direct neighbor can act as a "controller" or "monitor" designated for this network device. In addition, in the case of device replacement, in particular during the initialization phase, the replacement network device can ask its neighbor for such device information stored in the neighbor, said device information in particular including the configuration contained therein. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Further advantages and features of the invention, particular or preferred embodiments and further embodiments reproduced in the dependent claims are described in more detail in the following description with reference to the accompanying drawings. In the drawings:

[0013] Figure 1 a highly simplified diagram showing a preferred connection of network devices corresponding to a network topology for a network within the scope of the present invention, and

[0014] Figure 2 Shown as Figure 1A very simplified illustration of the connection of network devices is shown, but one of the network devices has been replaced. DETAILED DESCRIPTION

[0015] Preferred embodiments within the scope of the present invention will be described in detail below with reference to the accompanying drawings.

[0016] Figure 1 A highly simplified preferred connection of three network devices 1, 2 and 3 is shown, which are connected to a network 10 (not shown further) according to a network topology for this network within the scope of the invention. For the communication connection 40 between the individual network devices 1, 2 and 3, a bus, in particular a 2-wire bus, but also a bus comprising more than 2 wires or cores can be used.

[0017] Figure 1 Only a possible basic structure is shown. In the example shown, each network device 1, 2 and 3, i.e., in particular each bus subscriber, has two connection ports, each of which can be connected to another network device. For the first network device 1, the first connection port and the second connection port are marked as 11 and 12, respectively. Correspondingly, the first connection port and the second connection port on the second network device 2 are marked as 21 and 22, respectively, and the first connection port and the second connection port on the third network device 3 are marked as 31 and 32, respectively. However, alternatively, one or more network devices can have more than two connection ports. Therefore, the network device 2 is arranged between the network devices 1 and 3 and is therefore connected to the two in an adjacent manner, or the network device 1 and the network device 3 are each connected to the network device 2 in an adjacent manner.

[0018] In case of a bus as communication connection 40, any protocol that allows at least two or more network devices as subscribers is suitable. Examples are RS485, RS422, LIN or similar protocols.

[0019] In addition, in the example shown, each of these network devices 1, 2 and 3 is preferably configured to use a neighbor discovery protocol, and after being connected to the network 10, as shown by the dotted arrow, its own device information GI-1, GI-2 or GI-3 is sent to the network device connected to the network in an adjacent manner according to the network topology for the network, and is also configured to use the neighbor discovery protocol. Therefore, each of these network devices 1, 2 and 3 can also preferably receive device information GI-2, GI-1 and GI-3 or GI-2 from the network device connected to the network in an adjacent manner according to the network topology for the network, and is configured to use the neighbor discovery protocol. As described at the beginning, such neighbor discovery protocols are generally known in the prior art. Therefore, these neighbor discovery protocols can be manufacturer-independent, i.e., any layer 2 protocol, such as the link layer discovery protocol, or LLDP for short.

[0020] Furthermore, within the scope of the present invention, each of these network devices 1, 2 and 3 is also preferably configured, on the one hand, after being respectively connected to the network and after receiving device information from a network device connected to the network in an adjacent manner, to also store the received device information assigned to the network device, and on the other hand, to request its own device information from another network device connected to the network in an adjacent manner.

[0021] according to Figure 1 , therefore, the network device 2 is appropriately configured to store the device information GI-1 from the network device 1 and the device information GI-3 also from the network device 3, or the network devices 1 and 3 can therefore each store the device information GI-2 from the network device 2 in a corresponding manner. On the other hand, if Figure 1 As shown by the dashed arrows in , in principle, network device 2 can also request its own device information again from network device 1 and / or network device 3 at any time, or network devices 1 and 3 can each request their own device information again from network device 2 in a corresponding manner. This therefore also leads to an overall reduction of risks in the entire network, because in particular in the event that information in one of the network devices is lost for some reason, the "lost" device information can be easily requested again from the corresponding neighboring network device. For this request, application-specific settings can be made, for example so that it starts automatically or only after a separate initialization.

[0022] In particular, for reasons of a secure assignment between network devices and device information, in particular in the event of a device replacement, each of these device information items contains a data record which specifies the respective network device from which such device information originates or has been sent, in particular a data record associated with the network device type. Based on this, each of these network devices 1, 2, 3 can then be appropriately configured or the data record specified by this network device of the requested device information can be associated with the data record specifying the requesting network device (i.e. in particular the data set TYPID which is already stored in this data set and is associated with the network device type (see Figure 2 )) is compared to confirm the identity, whereby TYPID contains a unique identification, such as an ID, an order code or a similar identification, so that the device type can be uniquely identified and thus the network device can be specified. Specifically, depending on the application of the network device or the corresponding settings, it is stipulated that such identity comparison is performed by the network device from which the device information is requested or the network device requesting the device information. If the comparison network device is not the requesting network device, the requested device information can be sent to the requesting network device if the compared data sets are the same. If the comparison network device is the requesting network device and has therefore received the requested device information for comparison, the requested device information can be stored again at the requesting network device if the compared data sets are the same.

[0023] Therefore, in particular for the above appropriately configured network devices 1 , 2 , 3 , a backup procedure can be performed, and therefore in particular a decentralized backup procedure of the device information according to the present invention.

[0024] If, for example, network devices 1, 2 and 3 configured to use a neighbor discovery protocol are connected to the network 10, as described above with reference to Figure 1As described in the example of the embodiment, each device can, on the one hand, send its own device information GI-1, GI-2 or GI-3 to a network device connected to the network in an adjacent manner according to the network topology for the network, and is also set to use the neighbor discovery protocol and, on the other hand, also receive device information from other network devices connected to the network in an adjacent manner according to the network topology. Therefore, according to the backup method according to the present invention, after two adjacent network devices (such as network device 1 and network device 2 that are set to use the neighbor discovery protocol) have been turned on, at least the first of the two network devices has its own first device information (for example, network device 1 having its own first device information GI-1) sends the first device information to the second of the two network devices, that is, according to the underlying example, to, for example, network device 2, and stores it in a location assigned to the sending network device, that is, according to the underlying example, in network device 2 assigned to the sending network device 1, according to the underlying example, then, if the first network device, that is, network device 1 according to the underlying example, is replaced by network device 1' (see Figure 2 ) is replaced, and after the replacement network device 1' is turned on, it can request to send the stored first device information from the second network device, that is, the device information GI-1 at the network device 2 according to the underlying example.

[0025] Specifically, an identifier of a connection port by which the device information has been received may also be included for allocation between the network device that sent the device information and precisely the sent device information when it is stored in the receiving network device. Figure 1 As shown, the network device 1 is connected to or via the first connection port 21 of the second network device 2, and the network device 2 therefore only receives device information from the network device 1 via this connection port 21. If the network device 1 is now replaced by the network device 1' (see Figure 2 ) is replaced, the replacement network device 1' is therefore connected again to the first connection port 21 of the second network device 2 or connected via it. If the replacement network device 1' now requests the storage device information to be sent from the second network device 2, see Figure 2 The dot-dash arrow marked GI-1? in FIG. 1 also sends the request via the same connection port as the device information GI-1 previously received from the replaced network device 1. Therefore, the connection port can also be used to make an unambiguous allocation between the network device sending the device information and, more precisely, the sent device information (when it is stored in the receiving network device), and even in the case of requesting the stored device information via the same connection port, it is clear that the requested device information is the device information previously received via the connection port without explicitly including this information in the request.

[0026] As described above, requesting the first device information from the second network device may also be initiated automatically, or only after being separately initialized by the replacement network device, depending on the existing or specified application.

[0027] If, as has been described above with respect to a preferred embodiment of the network device, each of these device information items also contains a data record for the designated network device, in particular a data record relating to the type of the network device, then after the first device information item has been requested by the replacement network device from the second network device, this data record is preferably first compared for identity with the data record for the designated replacement network device (in particular a data record relating to the type of network device, in particular the data record TYPID stored therein), and if they are identical the first device information item is only stored in the replacement network device. In particular, if the data set for the designated replacement network device is also sent as part of the request, the comparison can therefore also be performed by a network device that is not the requesting network device.

[0028] If there is no identity, the own device information of the replacement network device is appropriately updated, for example according to the prior art described at the beginning, with the help of information stored in the (central) control unit, in particular information related to the specific configuration, and then the updated device information (in Figure 2 GI-1' in the figure) is sent to an adjacent network device, and thus in particular also to a second network device, for example according to Figure 1 and Figure 2 network device 2 and stored there.

[0029] However, in particular, in the case of updating own device information, it is intended that the corresponding network device sends it to at least one network device connected to it in an adjacent manner, in particular to each network device connected to it in an adjacent manner, and stores it there, assigned to the corresponding sending network device. It is convenient to delete the previously stored device information assigned to the previously replaced adjacent network device. Figure 2 , therefore, the device information GI-1' will be newly stored in the network device 2, and the device information GI-1 assigned to the previously replaced adjacent network device 1 will be conveniently deleted, i.e. the device information GI-1 will be replaced by the device information GI-1', conveniently in the storage area provided for this purpose.

[0030] Therefore, in particular within the scope of the present invention, when updating the own device information, data records (in particular configuration data records) assigned to the corresponding network device in an application-specific manner can be stored in the device information for the first time, or such data records (i.e. in particular configuration data records) assigned to the corresponding network device in an application-specific manner and stored in the device information can be updated.

[0031] exist Figure 1 and Figure 2 In the context of the backup method according to the invention, of course additionally or alternatively, Figure 1 The network device designated as network device 2 in FIG. 1 can also serve as the first network device, and Figure 1 The network device designated as network device 1 in FIG. 1 may also serve as a second network device, additionally or alternatively, Figure 1 The network device designated as network device 2 in FIG. 1 can also serve as the first network device and Figure 1 The network device designated as network device 3 in FIG. 1 may also serve as a second network device, additionally or alternatively, Figure 1 The network device designated as network device 2 in FIG. 1 can also serve as the first network device and Figure 1 The network device designated as network device 3 in FIG. 1 may also serve as a second network device, additionally or alternatively, Figure 1 The network device designated as network device 3 in FIG. 1 can also serve as the first network device and Figure 1 The network device designated as network device 2 in FIG. 1 can also serve as a second network device.

[0032] Return to the Figure 1 In the example of , the network 10 thus consists of, for example, a "chain" of three network devices 1, 2 and 3. At time t, these devices can each have their own device information and a separate data set, such as a separate configuration. After one or more network devices 1, 2, 3 have been set up accordingly (i.e. the corresponding own device information GI-1, GI-2, GI-3, i.e. in particular the corresponding separate data set, has been updated), this corresponding device information is also sent to at least one of the network devices connected thereto in a neighboring manner and stored there, appropriately in a storage area reserved for this purpose.

[0033] For example, immediately after the device information GI-2 is set for the network device 2, this device information GI-2 is sent to the network device 1 and / or 3 and stored there, ie conveniently in a memory area reserved for this purpose.

[0034] therefore, Figure 1 The network 10 shown in FIG. 1 can be arranged in the form of a daisy chain (point-to-point) wiring, so that each network device 1, 2 and 3 has at least one unique neighboring network device. Therefore, from the perspective of the network device, the directly neighboring network device can receive the configuration as an "unknown" data set.

[0035] In the case of a device replacement, the replacement network device can therefore ask at least one adjacent network device for device information previously stored there relating to the replaced network device, in particular including the configuration contained therein, or request this device information from an adjacent network device in particular during an initialization phase. In particular for security reasons, e.g. in order to avoid configuration conflicts, the device information should also be unique for the replacement network device. Therefore, the device information should also contain data records specifying the network device, in particular TYPID data records relating to the type of network device, i.e. a unique identification of the respective device type, such as an ID, order code or similar information. This means that adjacent network devices can save or decentrally store device information that they are not aware of but is assigned to directly adjacent network devices.

[0036] For example, refer to Figure 1 , the following combination of decentralized device information can produce a running, configured network:

[0037]

[0038]

[0039] If in a possible application scenario, such as a network device failure, for example, a network device 2 failure, the failed network device 2 is now replaced by a "new" replacement network device of the same type TYPID, then the "new" replacement network device of the same type can now query its neighboring network devices (such as network devices 1 and 3) for corresponding device information during the startup phase. If the device information is also valid for the "new" replacement network device, the device information can be transmitted to the "new" replacement network device as needed so that the "new" replacement network device can make any necessary settings. This is beneficial for configuration data, for example.

[0040] However, if in a possible application scenario, such as a failure of network device 2, the failed network device 2 is now replaced by a "new" replacement network device of a different or other TYPID type, and the "new" replacement network device now inquires its neighboring network devices for corresponding device information during the startup phase, it will be possible to determine that the decentralized stored device information is invalid for the "new" replacement network device. Therefore, the device information GI-2 previously stored for network device 2 in the neighboring network device can be deleted. However, specifically, after setting (i.e., updating) the device information of the "new" replacement network device, the device information can be stored in each neighboring network device in turn.

[0041] Of course, other and / or another data record type contained in the corresponding device information is also possible within the scope of the invention.

[0042] If another network device is connected to a free connection of a network device (such as the connection port 32 of the network device 3), corresponding device information can also be sent between the network devices connected adjacent to each other during operation.

[0043] Therefore, it is usually extremely important that, in particular at the beginning of the initialization phase, each network device (in particular a bus subscriber) can determine its function and position in the network, for example along a "chain", in particular according to the network topology used. Based on the possible startup sequence of the network devices 2, this can be achieved, for example, as follows.

[0044] After network device 2 is turned on, it waits for incoming device information from network devices 1 and / or 3 .

[0045] If network device 1 and / or network device 3 sends device information GI-1 or G-3 to network device 2, this "neighboring" device information is stored in network device 2 and is therefore saved there. If no device information is received via the connection port, no neighboring network device is connected there.

[0046] Therefore, the network device 2 sends its own device information GI-2 to all adjacently connected network devices 1, 3, or if necessary, can also restore the own device information GI-2, so that, in particular in the case where the network device 2 is a replacement network device, for example, the configuration assigned to the previously replaced network device can be provided to the network device 2 again by the adjacent network device 1 and / or the adjacent network device 3. Therefore, each network device knows its function and position.

[0047] As can be seen from the above description, in particular, the method according to the present invention can be implemented in pure software or pure hardware, or can also be provided by a combination of suitable hardware and software. A separate functional unit in a network device can also be provided for the method according to the present invention. Therefore, the facilities of the present invention according to a network device suitable for this purpose can also be implemented in pure software or pure hardware, or can also be provided by a combination of suitable hardware and software, and additionally or alternatively, a separate functional unit can be set in the network device for the facilities of the present invention according to a network device suitable for this purpose. For example, a separate functional unit can also be run as software on hardware (such as an existing processor) already present in the network device. However, hardware can also be provided specifically for a separate functional unit. A computer program can also be provided for the process according to the present invention, the separate functional unit and / or the installation, and the computer program includes a program code tool for executing the steps of the method according to the present invention. Similarly, a computer-readable medium (such as a CD-ROM or DVD or USB or flash memory) can also be used for this purpose, and the computer-readable medium includes instructions that, when executed on at least one computer, cause at least one computer to perform the steps of the method according to the present invention. However, such a computer-readable medium does not have to be just a physical medium, but can also be in the form of a data stream and / or a signal representing a data stream.

[0048] Reference numerals list

[0049] 1 First Network Equipment

[0050] 1' Replacement Network Equipment

[0051] 2 Second network device

[0052] 3 Third network device

[0053] 10 Network

[0054] 11 The first connection port of the first network device

[0055] 12 The second connection port of the first network device

[0056] 21 The first connection port of the second network device

[0057] 22 Second connection port of the second network device

[0058] 31 The first connection port of the third network device

[0059] 32 The second connection port of the third network device

[0060] 40 Communication links, in particular bus systems

[0061] GI-1, GI-2, GI-3, GI-1' Equipment information of the first, second, third network equipment or replacement network equipment

[0062] GI-1?, GI-2?, GI-3? Request device information of the first, second or third network device

[0063] TYPID network device specific data set.

Claims

1. A backup method for network devices (1, 2, 3) connected to a network (10) and designed to use a neighbor discovery protocol, wherein each of the network devices connected to the network and designed to use the protocol is designed to use the protocol to send its own device information to a neighboring network device connected to the network and configured to use the neighbor discovery protocol according to a network topology for the network, and to receive device information from a neighboring network device connected to the network and configured to use the neighbor discovery protocol according to the network topology, in: - After turning on two adjacent network devices (1, 2, 3) designed to use the neighbor discovery protocol, at least the first network device (1) of the two adjacent network devices having its own first device information sends the first device information to the second network device (2) of the two adjacent network devices, and the first device information is stored in the second network device in a manner associated with the sending network device, wherein if the first network device is replaced by a replacement network device, the stored first device information is requested to be sent from the second network device after the replacement network device has been turned on.

2. The backup method according to claim 1, wherein a manufacturer-independent Layer 2 protocol is used as the neighbor discovery protocol so as to exchange information related to the corresponding devices between devices connected to the network in a neighboring manner and configured to use the neighbor discovery protocol, in particular including device names and / or IP addresses for device identification.

3. The backup method according to claim 1 or 2, wherein the request for the first device information at the second network device is initiated by the replacement network device automatically or only after a separate initialization.

4. The backup method according to any one of claims 1 to 3, wherein each device information in the device information includes a data set specifying a network device, and after the replacement network device requests the first device information at the second network device, the data set is compared with a data set specifying the replacement network device, in particular, a data set stored in the replacement network device, and when the identity is confirmed, the first device information is stored in the replacement network device.

5. The backup method according to claim 4, wherein if the identity does not exist, the replacement network device's own device information is updated, and the updated device information is sent to the second network device (2) and stored in the second network device.

6. The backup method according to any one of the preceding claims 1 to 5, - wherein, in the case of updating own device information, this information is sent by the corresponding network device to at least one network device connected thereto in an adjacent manner, in particular to each network device connected thereto in an adjacent manner, and is stored in a network device assigned to the corresponding sending network device, and / or -in, When updating the own device information, data sets, in particular configuration data sets, which are assigned to the respective network device in an application-specific manner are stored in the device information for the first time or the data sets stored in the device information and assigned to the respective network device in an application-specific manner are updated.

7. A network device, the network device being configured to use a neighbor discovery protocol after being connected to a network to send its own device information to a network device connected to the network in a neighboring manner according to a network topology for the network, and being configured to use the neighbor discovery protocol and to receive device information from a network device connected to the network in a neighboring manner and configured to use the neighbor discovery protocol according to the network topology for the network, And furthermore the network device is arranged to, after being connected to the network and after receiving device information from a network device connected to the network in an adjacent manner, store the information assigned to the network device and request its own device information from another network device connected to the network in an adjacent manner.

8. The network device according to claim 7, wherein each device information of the device information contains a data set specifying the network device, and the network device is also designed to compare the data set of the requested device information with the data set specifying the requested network device, in particular the data set stored in the requested network device, and when the identity is confirmed, if the network device is not the requested network device, send the requested device information to the requested network device, or if the network device is the requested network device, store the requested device information.

9. A computer program comprising program code means for carrying out the method according to any one of claims 1 to 7.

10. A computer-readable medium comprising instructions which, when executed on at least one computer, cause the at least one computer to perform the steps of the method according to any one of claims 1 to 8.

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