Controlling transfer of configuration information

Abstract

The invention relates to a method (100a, 100b, 100c) for operating an Ethernet network (10). According to the method (100a, 100b, 100c), the transfer (102) of configuration information relating to an operation of network bridges (12, 14, 16) of the Ethernet network (10), in particular the transfer of bridge protocol data units (BPDU) of a spanning tree protocol is controlled (104, 106, 114, 116).

Description

[0001]202222301 1 Description Controlling a forwarding of configuration information The invention relates to a method for operating an Ethernet network, an Ethernet network as well as a computer program and a computer-readable medium. Computer networks are often set up as Ethernet networks for the purpose of exchanging data. In this way, both the physical layer of the OSI layer model (level 1) and the data link layer of the OSI layer model (level 2) are defined. Such computer networks have a large number of network bridges which provide a large number of possible paths for the purpose of transmitting data packets. In order to ensure that a clear communication connection can be provided between two communication participants in the computer network, a key task is to keep a network topology free of multiple paths and loops.For this purpose, the spanning tree protocol (STP) or further developments based on it, such as RSTP (rapid spanning tree protocol) or MSTP (multiple spanning tree protocol), are already known. A network topology in which multiple paths exist is converted into a tree topology using the aforementioned protocols. In this way, multiple paths are avoided. A key aspect of the spanning tree protocol is the selection of a so-called root network bridge from the aforementioned network bridges, through which all data packets are transmitted. According to the spanning tree protocol, the selection is made such that the network bridge assigned the highest priority is selected as the root network bridge.If two network bridges of the same priority are competing for selection as the root network bridge, the network bridge with the smallest MAC address is selected as the root network bridge. If a root network bridge selected in this way fails, a new root network bridge is selected from the remaining network bridges according to the aforementioned criteria. However, the process for selecting a new root network bridge is time-consuming depending on the network topology. While a search for a new root network bridge is underway, no communication can take place via the Ethernet network. The failure of a root network bridge therefore results in a data transmission failure. This represents a significant risk with regard to availability, particularly for time-critical applications.To reduce this risk, it is already known to quickly locate a new root network bridge using predetermined network topologies, such as a ring topology. However, for mixed network topologies, such as an H-topology or a ladder topology, there has so far been no method by which a sufficiently fast location of a new root network bridge can be realized. In particular, mixed network topologies in the aforementioned RSTP lead to a considerable delay in finding a new root network bridge. The invention is based on the object of improving the availability and reliability of a computer network. This object is achieved by a method according to the features of claim 1. Furthermore, the object of the invention is to provide an Ethernet network by means of which the inventive method can be carried out.This object is achieved by an Ethernet network according to the features of the independent device claim. 202222301 3 Furthermore, the invention is based on the objects of providing a computer program and a computer-readable medium. These objects are achieved by a computer program according to the features of the independent computer program claim and with a computer-readable medium according to the features of independent claim 15. Advantageous developments of the invention are each the subject of dependent subclaims. The method according to the invention relates to the operation of an Ethernet network. The method according to the invention controls the forwarding of configuration information relating to the operation of network bridges in the Ethernet network. The configuration information is in particular so-called "bridge protocol data units" of a spanning tree protocol.These "bridge protocol data units" are usually abbreviated using the acronym "BPDU." In this context, network bridges are understood to be network connection elements through which data is transmitted on the second level of the OSI standard model. In particular, network bridges are designed as so-called MAC bridges. Network bridges typically include a microcontroller, a processor, or other programmable hardware component configured to read, write, transmit, and / or manage data. The spanning tree protocol is a network protocol known among experts as the "spanning tree protocol."In the present context, the spanning tree protocol refers to both the "spanning tree protocol" and developments based on it, such as the "rapid spanning tree protocol (RSTP)" or the "multiple spanning tree protocol (MSTP)." The purpose of the spanning tree protocol is to achieve loop-free performance in any network topology. A network topology, in this context, is understood to be a signal topology of an Ethernet network based on the first level of the OSI standard model. Examples of network topologies are ring, star, or H-topologies, as well as combinations thereof. The method according to the invention makes it possible to improve network communication in a cost-effective manner based on an addition to or modification of a spanning tree protocol.In the case of mixed network topologies, downtimes can be significantly reduced by simply making a minor modification to the spanning tree protocol. Furthermore, the creation of alternative protocols and the associated conversion of existing networks can be dispensed with. This enables high compatibility with existing networks. An advantageous further development provides for the forwarding of configuration information to be controlled based on information concerning the priority of the sender of the configuration information. Typically, a network bridge assigned a high reference value has a lower priority than a network bridge assigned a comparatively lower reference value.Information regarding a sender's priority, which is already included as standard in a piece of configuration information, can be easily used to control forwarding. This prevents increased data volumes and thus increased network loads with additional data volumes. A further advantageous development provides for the forwarding of configuration information to be controlled based on a predefined priority threshold. Configuration information whose senders have a priority lower than the priority threshold can thus be easily excluded from forwarding. The amount of configuration information to be forwarded can thus be reduced in a cost-effective and needs-based manner.Furthermore, an advantageous development provides that the forwarding of configuration information is controlled based on information concerning a change in the network topology. A change in the network topology can be caused by the addition or removal of network participants from the Ethernet network. Furthermore, a change in the network topology can occur, for example, as soon as a network participant fails unexpectedly. A particularly extensive change in the network topology occurs when a root network bridge fails. A method deviating from the standard method according to the spanning tree protocol can thus be limited to cases in which changes in the network topology have occurred. In this way, the efficiency of the method for controlling forwarding can be increased at low cost.In an advantageous embodiment, the forwarding of configuration information is controlled based on information concerning a failure of a root network bridge. This makes it possible to deviate from the standard procedure according to the spanning tree protocol only if there is a fundamental and significant change in the network topology. Furthermore, it is possible to easily prevent the forwarding of configuration information originating from the failed root network bridge after its failure. In the event of a failure of the root network bridge, a new root network bridge can be selected particularly quickly. Furthermore, misinterpretations regarding configuration information originating from the failed 202222301 6 root network bridge can be easily prevented.Furthermore, a further advantageous development provides that, in the event of a root network bridge failure, information regarding the root network bridge failure is forwarded via additional network bridges in the Ethernet network. A network bridge that receives the information regarding the root network bridge failure is placed in a separate operating state. Based on the separate operating state, filters can be easily implemented to accelerate the discovery of a new root network bridge. This makes it easy to reduce downtimes in the communication network.In an advantageous embodiment, it is provided that, by means of a network bridge in the separate operating state, only those configuration information are forwarded whose sender is assigned a priority that is higher than the priorities of senders of configuration information already received by the network bridge during the separate operating state. The network bridge expediently stores the priorities of the senders of configuration information already received in the separate operating state. This allows the amount of configuration information to be processed by subsequent network bridges to be easily and effectively reduced. This shortens processing time and can thus accelerate the discovery of a new root network bridge.A further advantageous embodiment provides that, using a network bridge in the separate operating state, only configuration information is forwarded whose sender is assigned a priority that is lower than the priority assigned to the failed root network bridge. Configuration information originating from the failed root network bridge, which continues to be forwarded within the Ethernet network after a failure of this root network bridge, can thus be easily ignored. Incorrect configuration of individual network bridges due to the intended high priority of the root network bridge can thus be easily prevented.Furthermore, an advantageous embodiment relates to the case in which configuration information is received whose sender is assigned the same priority as a sender of configuration information that has already been received and forwarded. In this case, it is proposed that forwarding be carried out on the basis of information concerning associated path costs. The configuration information to be forwarded is preferably only forwarded if it is assigned lower path costs than those assigned to the configuration information already forwarded. The efficiency of the method can thus be further increased. Another advantageous embodiment provides that a network bridge is placed in a separate operating state for a predetermined period of time from the time the information concerning the failure of the root network bridge is received.Intervention in the program code of already implemented protocols can thus be kept to a minimum. Furthermore, a particularly rapid and time-efficient method for resuming communication via the Ethernet network can be implemented. In an advantageous embodiment, the network bridge is placed in the separate operating state for a period of at most 10 seconds, preferably at most 8 seconds, and particularly preferably at most 4 seconds, from the time of receipt of the information concerning the failure of the root network bridge. 202222301 8 Furthermore, an advantageous development provides that the forwarding of configuration information is controlled based on information concerning a position of a failed root network bridge in the Ethernet network.Provided a knowledge of a network topology is available, configuration information originating from the root network bridge can be easily filtered out in the event of a failure of the said root network bridge. Forwarding of configuration information originating from the failed root network bridge can thus be easily and efficiently prevented. For example, runtimes or path costs can be used to control the forwarding of configuration information. A further advantageous development provides for the forwarding of configuration information to be controlled based on information regarding the direction of origin of the configuration information.Knowledge of the structure of an existing network topology can be used to disregard configuration information originating from a failed root network bridge and still forwarded after a failure within the Ethernet network. Configuration information forwarded by network bridges after a root network bridge failure can thus be easily identified based on a direction of origin. The process of finding a new root network bridge can therefore be significantly accelerated. Furthermore, this can effectively prevent configuration information from the failed root network bridge from being mistakenly taken into account by individual network bridges. Furthermore, the method according to the invention is preferably a computer-implemented method for the purpose of operating an Ethernet network.The inventive method can be carried out by means of the Ethernet network according to the invention. 202222301 9 The inventive Ethernet network has a plurality of network bridges which are configured to carry out the inventive method. In this way, a network for the purpose of operating time-critical applications can be implemented at low cost. Network downtimes can be significantly reduced in this way. Furthermore, existing networks can be easily supplemented and improved. Furthermore, the invention provides a computer program which, when executed, causes the inventive Ethernet network to carry out the inventive method. In addition, the present invention provides a computer-readable medium. This has instructions which cause the inventive Ethernet network to carry out the inventive method.The computer-readable medium can be, for example, a CD-ROM, a DVD, a USB or flash memory, or a non-physical medium such as a data stream and / or a data carrier signal. The properties, features, and advantages of the invention described above, as well as the manner in which they are achieved, are explained in more detail in conjunction with the figures in the following description of the embodiments of the invention. Where appropriate, the same reference numerals are used in the figures for the same or corresponding elements of the invention. The following exemplary embodiment, as well as described variations thereof, serve to explain the invention and do not limit the invention to the combinations of features specified therein, including with regard to functional features.In addition, all 10 features specified in the exemplary embodiment can be considered in isolation and combined as appropriate with the features of any claim. FIG. 1 illustrates a first example of the method according to the invention in a schematic representation; FIG. 2 illustrates a second example of the method according to the invention in a schematic representation; FIG. 3 illustrates a third example of the method according to the invention in a schematic representation; FIG. 4 shows an exemplary embodiment of the Ethernet network according to the invention, which is configured to carry out the method according to the invention. FIG. 1 illustrates a first example of a method 100a for operating an Ethernet network 10.Using the example of method 100a, the already known spanning tree protocol is modified such that a forwarding 102 of configuration information relating to the operation of network bridges 12, 14, 16 of the Ethernet network 10 is controlled 104. For example, the configuration information is so-called "Bridge Protocol Data Units" of a spanning tree protocol. For the sake of clarity, the corresponding acronym "BPDU" is used below instead of the English term "Bridge Protocol Data Units." The first example of method 100a provides that a priority threshold is specified for each of the network bridges 14, 16 of the Ethernet network 10.In addition to a procedure specified by 202222301 11 of the spanning tree protocol, the received 112 BPDUs are checked based on the specified priority threshold to determine whether a priority of a sender of the BPDU exceeds the priority threshold 104. If the specified priority threshold is exceeded, the received BPDU is forwarded 102 according to the specifications of the spanning tree protocol. If, however, the priority threshold is not exceeded, a check is carried out to determine whether information regarding a change in the network topology is present 106. In the first example of the method 100a described here, it is provided that a change in the network topology occurs at least as soon as a root network bridge 12 fails.In the event that the root network bridge 12 fails, the first example of the method 100a provides that information regarding the failure of the root network bridge 12 is forwarded 108 within the Ethernet network 10. If the said information regarding the failure of the root network bridge 12 is received 112 by a network bridge 14, 16, the network bridge stores the said information. For example, the said information is stored using a status indicator. If a network bridge 14, 16 has the information that the root network bridge 12 has failed, BPDUs whose sender is assigned a priority that falls below the predefined priority threshold are also forwarded 102.If, however, a network bridge 14, 16 has no information regarding an existing failure of the root network bridge 12, BPDUs originating from a sender assigned a priority that falls below the specified priority threshold are not forwarded 102, contrary to the standard specifications of the spanning tree protocol. According to the first example of the method 100a, a forwarding 102 of BPDUs is therefore controlled 104, 106 based on a priority of a sender 12 and on a change in a network topology. FIG. 2 illustrates a second example of a method 100b for operating an Ethernet network 10. The second example of the method 100b illustrated in connection with FIG. 2 represents a further development of the first example of the method 100a described in connection with FIG. 1.In contrast to the first example of the method 100a, no priority threshold is specified for the network bridges 14, 16. Instead, a network bridge 14, 16 is placed 110 in a separate operating state upon receipt 112 of information concerning a failure of the root network bridge 12. For example, an affected network bridge 14, 16 is placed 110 in the separate operating state for a limited period of 10 seconds. In the second example of the method 100b, it is provided that, by means of the network bridges 14, 16 in the separate operating state 110, only those BPDUs are forwarded 102 whose sender is assigned a priority that is higher than the priorities of senders of 112 BPDUs already received by the network bridge 14, 16 during the separate operating state 110. In this way, a fixed priority threshold can be dispensed with.Instead of the predefined priority threshold, the forwarding 102 of BPDUs is therefore controlled 104 based on a sliding priority threshold. This sliding priority threshold depends on the priorities of the senders of 112 BPDUs already received. Furthermore, the second example of the method 100b provides that, by means of network bridges 14, 16 in the separate operating state 110, only those BPDUs are forwarded 102 whose sender is assigned a priority that is lower than the priority assigned to the failed root network bridge 12. In the special case that during the separate operating state 110, BPDUs are received 112 by a network bridge 14, 16, in which the senders have the same priority value, the affected BPDU is forwarded 102 based on information concerning associated path costs.For example, if BPDUs have already been received 112 whose sender is assigned the same priority as a currently received 112 BPDU, the path costs of the already forwarded 102 BPDUs and the path costs of the currently received 112 BPDUs are compared. If the currently received 112 BPDUs have lower path costs than the already forwarded 102 BPDUs, the currently received 112 BPDUs are forwarded 102. If, on the other hand, the currently received 112 BPDUs have higher path costs than an already forwarded 102 BPDU, the currently received 112 BPDUs are not forwarded 102. FIG. 3 illustrates a third example of a method 100c for operating an Ethernet network 10.The third example of the method 100c illustrated in connection with FIG. 3 can be used alternatively or in addition to the first example of the method 100a described above in connection with FIG. 1 and / or to the second example of the method 100b described above in connection with FIG. 2. The third example of the method 100c is based on knowledge of a network topology of the Ethernet network 10. Based on this knowledge, a position of the root network bridge 12 and a position of the remaining network bridges 14, 16 are known. Based on the knowledge of the relative position of the network bridges 12, 14, 16 to one another, a forwarding 102 of BPDUs is controlled 114 in the third example of the method 100c described here.For example, knowledge regarding the position of the network bridges 12, 14, 16 in the Ethernet network 10 is utilized by controlling 116 the forwarding of the BPDU 102 based on information regarding a direction of origin of the BPDU. For this purpose, the network topology 14 of the Ethernet network 10 is preferably configured such that a root network bridge 12 and, immediately adjacent to it, a further network bridge 14 are arranged on a predetermined side of the network topology. The further network bridge 14 is a network bridge to which a priority is assigned, on the basis of which this further network bridge 14 is selected as the new root network bridge 14 in the event of a failure of the root network bridge 12. Basically, according to the spanning tree protocol, the BPDU originating from the root network bridge 12 is forwarded 102 by the remaining network bridges 14, 16 of the Ethernet network 10.In this way, a duplication of individual BPDUs takes place in meshed networks. Therefore, BPDUs from the same sender and with the same content can be received 112 from different directions by a network bridge 12, 14, 16. With the help of knowledge of the positions of the network bridges 12, 14, 16 relative to one another, it is possible in the present case to control 116 the forwarding of BPDUs based on a direction of origin of the BPDU. For the purpose of further illustrating the third example of the method 100c, an embodiment of an Ethernet network 10 is shown schematically in FIG. 4. By way of example, the Ethernet network 10 has a plurality of network bridges 12, 14, 16. The network bridges 12, 14, 16 are arranged in the form of an H-topology. On the left side of the schematic representation, the root network bridge 12 and the aforementioned further network bridge 14 are positioned as an example.According to the third example of the method 100c described in connection with FIG. 3, a forwarding 102 of BPDUs of the root network bridge 12 is prevented 116 as soon as they are received 112 by a network bridge 14, 16 from a direction from a right side of the schematic representation in FIG. 4. In contrast, those BPDUs which are received 112 from a direction other than the right side of the representation in FIG. 4 are forwarded 102 according to the standard specifications of the family tree protocol. In this way, the forwarding 102 of BPDUs in the Ethernet network 10 shown by way of example in FIG. 4 is controlled 114, 116 based on a position of the network bridges 12, 14, 16 and based on a direction of origin of a BPDU. It is conceivable that the aforementioned control 114, 116 is limited only to cases in which the root network bridge 12 has failed.Preferably, a controller 114, 116 of the forwarding 102 is implemented based on a position of the network bridges 12, 14, 16 and on the basis of a direction of origin, but independently of a failure of the root network bridge 12. The Ethernet network 10 shown schematically in FIG. 4 is further configured to carry out, by way of example, the first example of the method 100a described in connection with FIG. 1 and the second example of the method 100b described in connection with FIG. 2. Combinations of the first example of the method 100a or the second example of the method 100b with the third example of the method 100c are also conceivable. Depending on the configuration, the Ethernet network 10 is configured, by way of example, to carry out the described methods 100a, 100b, 100c alone or in combination.Therefore, the network bridges 12, 14, 16 shown are in particular the network bridges 12, 14, 16 described in connection with FIG. 1, FIG. 2 and / or FIG. 3. Although the invention has been illustrated and described in more detail by the preferred embodiments, the invention is not limited by the disclosed examples, and other variations can be derived therefrom by a person skilled in the art without departing from the scope of the invention. 202222301 16 Regardless of the grammatical gender of a particular term, persons with male, female, or other gender identities are also included.

Claims

202222301 17 claims 1. A method (100a, 100b, 100c) for operating an Ethernet network (10), in which a forwarding (102) of configuration information relating to the operation of network bridges (12, 14, 16) of the Ethernet network (10), in particular a forwarding (102) of bridge protocol data units of a spanning tree protocol, is controlled (104, 106, 114, 116).

2. The method (100a, 100b, 100c) according to claim 1, in which a forwarding (102) of configuration information is controlled (104) based on information relating to a priority of the sender of the configuration information.

3. The method (100a, 100b) according to claim 2, wherein forwarding (102) of configuration information is controlled (104) based on a predetermined priority threshold.Method (100a, 100b, 100c) according to one of the preceding claims, in which a forwarding of configuration information is controlled (106) on the basis of information relating to a change in the network topology.

5. Method (100a, 100b, 100c) according to claim 4, in which a forwarding (102) of configuration information is controlled (106) on the basis of information relating to a failure of a root network bridge (12).

6. Method (100b, 100c) according to one of the preceding claims, in which - in the event of a failure of a root network bridge (12), information relating to the failure of the root network bridge (12) is forwarded (108) by means of further network bridges (14, 16) of the Ethernet network (10). 202222301 18 - a network bridge (14, 16), which has received (112) the information concerning the failure of the root network bridge (12), is placed into a separate operating state (110).

7. The method (100b, 100c) according to claim 6, wherein, by means of a network bridge (14, 16), in the separate operating state (110), only those configuration information items are forwarded (102) whose sender is assigned a priority that is higher than the priorities of senders of configuration information already received (112) by the network bridge (14, 16) during the separate operating state (110).Method (100b, 100c) according to one of claims 6 to 7, in which, by means of a network bridge (14, 16) in the separate operating state (110), only such configuration information is forwarded (102) whose sender is assigned a priority that is lower than a priority assigned to the failed root network bridge (12).

9. Method (100b, 100c) according to one of claims 6 to 8, in which, in the event that configuration information is received (112) by a network bridge (14, 16) whose sender is assigned the same priority, forwarding takes place (102) based on information concerning associated path costs.

10. The method (100b, 100c) according to one of claims 6 to 9, wherein a network bridge (14, 16) is placed into the separate operating state (110) for a predetermined period of time from the time of receipt (112) of the information concerning the failure of the root network bridge (12).Method (100c) according to one of the preceding claims, in which a forwarding (102) of configuration information is based on information relating to a position. 202222301 19 a failed root network bridge (12) is controlled (114).

12. Method (100c) according to one of the preceding claims, in which a forwarding (102) of configuration information is controlled (116) on the basis of information relating to a direction of origin of the configuration information.

13. Ethernet network (10) comprising a plurality of network bridges (12, 14, 16) which are configured to carry out the method (100a, 100b, 100c) according to one of the preceding claims.

14. Computer program which, when executed, causes the Ethernet network (10) according to claim 13 to carry out the method (100a, 100b, 100c) according to one of claims 1 to 12.

15. A computer-readable medium comprising instructions that cause the Ethernet network (10) of claim 13 to perform the method (100a, 100b, 100c) of any one of claims 1 to 12.

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