Efficient management method, device, equipment and storage medium for routing table items

Abstract

The present invention discloses an efficient management method, device, equipment and storage medium for routing table items, the method comprising: obtaining the network planning requirements of the user; modifying the Trie Tree Bitmap Group planning according to the network planning requirements, and implementing the corresponding routing table items in a one-layer tree structure; wherein, in the one-layer tree structure, all Bitmap fields are used to store routes with a prefix length; and implementing routing operations and IP forwarding based on the modified routing table items. The present invention opens the Trie Tree Bitmap Group planning and customizes it according to the user's network planning requirements, and implements the required large-scale routing patterns in a one-layer tree manner, giving full play to the advantages of the Trie Tree and providing the routing specifications with the largest prefix length required by the user. In addition, after the routing table items are implemented in a one-layer tree manner, the number of forwarding chip table items that need to be operated for each routing operation is greatly reduced, and the best routing operation performance can also be provided.

Description

Technical Field

[0001] The present invention relates to the network field, and in particular to an efficient management method, device and equipment for routing table items. Background Art

[0002] Network devices can be divided into two planes - the control plane and the forwarding plane. The tasks performed in the control plane determine how packets should be processed and forwarded. The control plane performs these control tasks and fills the forwarding table in the data plane. The data plane receives network traffic packets from the ports of the forwarding chip, parses the L2 / L3 / L4 protocol headers in the packets, and takes further forwarding. The forwarding chip is used to parse the packet header and check the forwarding table based on the parsing results to determine the next step. If a legal physical interface can be obtained after looking up the forwarding table, the queue and schedule it to go out from that interface; if the packet violates the traffic rules or fails the security check, the packet is discarded.

[0003] The FIB (Forwarding Information Base) is stored in on-chip or off-chip memory (SRAM, HBM / DRAM or TCAM). It contains just enough information to forward packets to their next destination or next hop. These forwarding tables are updated by the control plane software in the background without interrupting data plane traffic. For IP forwarding, the FIB corresponds to the routing table - including the host routing table and the longest prefix match routing table (Longest Prefix Match). The host routing table is mainly used to store the host IP addresses within the directly connected subnet, and contains the routing table entries of the directly connected hosts; the host table entries are filled by exchanging ARP request and reply messages; the host routing table is searched using the full routing match method, IPv4 is a 32-bit address, and IPv6 is a 128-bit address. The Longest Prefix Match (LPM) routing table is mainly used to store the routing table entries of remote subnets; network devices run routing protocols and obtain routing information of remote subnets by exchanging routing information with neighboring network devices.

[0004] A routing table typically contains an IP address, a subnet mask (or IP prefix), and a next hop. Depending on the hardware implementation, the next hop can directly indicate the physical interface to which the packet should be forwarded along its path to the final destination. Or it can point to an entry in another table that contains a set of instructions on how to calculate the outgoing interface for the packet. During the route lookup process, if DIP hits the host routing table, the query result of the host routing table is used to forward the message directly to the target host; if DIP does not hit the host routing table, the query result of the longest prefix match routing table is used to forward the message to the target subnet. LPM routes are IP addresses that contain the length of the subnet prefix. If several subnet prefixes are hit at the same time, the one with the longest mask matches successfully and is further forwarded.

[0005] Table 1 shows a conceptual routing table for an IPv4 address, using a simplified format for a routing table entry that contains the IPv4 address, subnet mask, and outgoing interface. The actual routing table structure is complex, shared between IPv4 and IPv6 addresses, contains several additional fields that are used with the destination address for lookups, and contains more information to specify various operations on the packet. IPv6 entries are similar to IPv4 addresses, except that their addresses (128 bits) are much wider than IPv4 (32 bits).

[0006]

[0007] If the routing table were to contain every IP address used on the planet, it would require billions of entries, and it would be impossible to store them in hardware. For example, a 32-bit IPv4 address would require about 4 billion entries. Network devices often aggregate routes that are not directly connected, referred to as subnets. The aggregated valid routing addresses are indicated using a subnet mask, and the table lookup only looks at the bits in the destination address of the incoming packet where the mask is set to 1. For example, for an entry with a network destination of 192.168.0.0 and a mask of 255.255.0.0, the mask, when expanded to binary format, has the upper 16 bits set, and this number 16 is called the prefix length, and the routing table entry is called 192.168.0.0 / 16 (or 192.168.*). Storing the subnet mask as a prefix length reduces the width of the entries in the routing table.

[0008] During IP forwarding, when the forwarding chip receives an IP packet, it uses the destination IP address to search the routing table to find all matching entries. When searching, it uses the prefix length to mask out irrelevant address bits to determine whether the routing entry matches.

[0009] Taking the route table lookup process with a DIP of 192.168.1.108 as an example, entries 1, 2, 3, and 6 in Table 1 are matched. Among all the matching entries, the one with the longest prefix is ​​entry 6, which represents the most precise way to reach the next hop, and the forwarding chip should select this entry for further forwarding. The most precise entry among all the matching entries, that is, the entry with the longest prefix length, is called the Longest Prefix Match (LPM). Prefix overlap is very common in the forwarding table and can provide the best path for the data packet as it passes through multiple network devices to reach the destination.

[0010] The routing table database in a typical high-end network device has millions of entries. With the widespread adoption of IPv6 forwarding, the number of routing entries stored in forwarding chips continues to grow. In addition, network chip vendors are supporting more and more bandwidth in each forwarding chip, which puts a great burden on the packet processing engine. The forwarding chip needs to support LPM table lookups at a very high rate.

[0011] A common solution for implementing LPM tables is to use a 0-1 prefix tree (Trie Tree) to store routes. Figure 1 As shown in the figure, a routing table entry can represent multiple routing prefixes. This solution can save the on-chip storage space of the forwarding chip, and at the same time have a better table lookup processing rate, as well as fast table entry insertion and deletion efficiency. The address of the routing table entry corresponds to the root node of the Trie Tree; the Trie Tree Bitmap corresponds to the specific route stored in the leaf node, and the width of the Bitmap corresponds to the number of routing entries that can be stored in a routing table entry.

[0012] Figure 1 In the figure, the Trie Tree Bitmap in the table entry has 31 bits, corresponding to a Trie Tree with 31 nodes from 192.168.0.0 / 16 to 192.168.x.0 / 20, that is, a routing table entry can represent up to 31 routes. In the figure, the 1st and 4th bits in the Bitmap are set to 1, indicating that the routing table summarizes the two routes 192.168.0.0 / 17 and 192.168.64.0 / 18.

[0013] In order to provide the largest routing table entry specifications for the global forwarding chip, the TrieTree Bitmap Group is usually pre-divided in the implementation. As shown in Table 2, the Trie Tree Bitmap Group planning for IPv4 is given, which is divided into the rootprefix length and the prefix length corresponding to the bitmap.

[0014]

[0015] From the application perspective, it is necessary to consider the routing specifications, which correspond to the carrying capacity of the network device. A simple way to increase the routing specifications is to increase the size of the routing table memory on the forwarding chip. When the memory size is determined, how to give users the maximum routing specifications is a great test of the availability of the network device.

[0016] Using Trie Tree to implement the storage of routing tables can expand the storage capacity of routing table items by supporting routes with various masks. When planning network services, network customers usually use specific pattern routes, using certain fixed prefixes and masks. If the routes with certain prefixes happen to be at the root node of the Trie Tree Bitmap, storing the routes with the prefixes will waste routing storage space.

[0017] For example, according to the Trie Tree Bitmap Group planning in Table 2, if there is an application requirement for large-scale routing table entries for routes with a prefix length of 16, because the routing table entries with a prefix length of 16 are all planned to the root node, each entry can only store one route, and the advantage of Trie Tree in efficiently storing routing table entries cannot be brought into play, which wastes the storage space of routing table entries.

[0018] In addition, from the application perspective, the performance of routing operations also needs to be considered. The performance of routing operations is mainly positively correlated with the number of times the forwarding chip is operated. How to reduce the number of times the forwarding chip is operated is a problem that needs to be solved. Summary of the invention

[0019] In view of the above problems, an object of the embodiments of the present invention is to provide a method, apparatus, device and storage medium for efficiently managing routing table entries, so as to improve the above problems.

[0020] An embodiment of the present invention provides an efficient management method for routing table entries, which includes:

[0021] Obtain users' network planning requirements;

[0022] According to the network planning requirements, the Trie Tree Bitmap Group planning is modified to implement the corresponding routing table items in a one-layer tree structure; wherein, in the one-layer tree structure, all Bitmap fields are used to store routes with a prefix length;

[0023] Routing operations and IP forwarding are implemented based on the modified routing table entries.

[0024] Preferably, a user-defined prefix plan is superimposed on the global default prefix plan, and the user-defined prefix plan is used to record the network planning requirements input by the user;

[0025] During loading, if it is determined that a user-defined prefix plan exists, the user-defined prefix plan is used by default; otherwise, the global default prefix plan is used.

[0026] Preferably, the network planning requirement of the user is a route with a predetermined mask length customized by the user.

[0027] Preferably, the user's network planning requirement is the routing space utilization rate; wherein, after the routing space utilization rate reaches a set threshold, the routing compression mechanism is started to store a large number of routes with low storage efficiency for specific prefixes using a one-layer tree structure.

[0028] Preferably, in the Trie Tree Bitmap Group planning, a single-layer tree structure or a multi-layer tree structure is determined by setting a specific field; when the specific field is set, a single-layer tree structure is adopted, and when the specific field is left blank, a multi-layer tree structure is adopted.

[0029] Preferably, in a multi-layer tree structure, the number of bits in the Bitmap field is 2 n -1 bit, n is the number of levels in the multi-layer tree structure; in a tree structure with one layer, the number of bits in the Bitmap field is 2 n Bit.

[0030] Preferably, it also includes:

[0031] This is accomplished by placing the routing of specific field settings in separate storage units.

[0032] The embodiment of the present invention further provides an efficient management device for routing table entries, which includes:

[0033] A demand acquisition unit, used to acquire the user's network planning requirements;

[0034] A modification unit, used to modify the Trie Tree Bitmap Group plan according to the network planning requirements, and implement the corresponding routing table items in a one-layer tree structure; wherein, in the one-layer tree structure, all Bitmap fields are used to store routes with a prefix length;

[0035] The forwarding unit is used to implement routing operations and IP forwarding based on the modified routing table entries.

[0036] An embodiment of the present invention further provides an efficient management device for routing table entries, which includes a memory and a processor, wherein the memory stores a computer program, and the computer program can be executed by the processor to implement the efficient management method for routing table entries as described above.

[0037] An embodiment of the present invention further provides a computer-readable storage medium storing a computer program, wherein the computer program can be executed by a processor of a device where the computer-readable storage medium is located to implement the efficient management method of routing table items as described above.

[0038] The present invention opens the Trie Tree Bitmap Group planning and customizes it according to the user's network planning requirements. The required large-scale routing patterns are all implemented in a one-layer tree manner, giving full play to the advantages of the Trie Tree and providing the routing specifications with the largest prefix length required by the user. In addition, after the routing table items are implemented in a one-layer tree manner, the forwarding chip table items that need to be operated for each routing operation are greatly reduced, and the best routing operation performance can also be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solution of the present invention, the drawings required for use in the implementation mode will be briefly introduced below. Obviously, the drawings described below are only some implementation modes of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0040] Figure 1 This is an example diagram of an existing routing prefix tree.

[0041] Figure 2 It is a flowchart of an efficient management method for routing table items provided by the first embodiment of the present invention.

[0042] Figure 3 This is a schematic diagram of the implementation method of a routing table entry with the expand bit set to 1.

[0043] Figure 4 This is a schematic diagram of the implementation method of a routing table entry with the expand bit set to 0.

[0044] Figure 5 It is a schematic diagram of the structure of an efficient management device for routing table entries provided by the second embodiment of the present invention. DETAILED DESCRIPTION

[0045] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0046] See also Figure 2 and Figure 3 The first embodiment of the present invention provides an efficient management method for routing table entries, which can be executed by an efficient management device for routing table entries (hereinafter referred to as a management device), and in particular, executed by one or more processors in the management device to implement the following method:

[0047] S101, obtaining the user's network planning requirements.

[0048] In this embodiment, the network planning requirement may be a large-scale routing prefix length sequence that the user is concerned about, or may be a routing space usage rate set by the user, which is not specifically limited in the present invention.

[0049] S102, modifying the Trie Tree Bitmap Group plan according to the network planning requirements, and implementing the corresponding routing table entries in a one-layer tree structure; wherein, in the one-layer tree structure, all Bitmap fields are used to store routes with a prefix length.

[0050] In this embodiment, an additional specific field can be added to the Trie Tree Bitmap Group plan to determine whether to use a single-layer tree structure or a multi-layer tree structure; when the specific field is set, a single-layer tree structure is used, and when the specific field is left blank, a multi-layer tree structure is used.

[0051] like Figure 3 As shown, the specific field is expand. When the specific field is empty, Trie Tree adopts a multi-layer tree structure. When expand is set, Trie Tree is implemented as a one-layer tree structure, and all Bitmap fields are used to store routes with a prefix length, so that the routing specification requirements of the user's specific mask length are fully met. At this time, the advantages of Trie Tree can be brought into play to provide the routing specification with the largest prefix length required by the user. Moreover, after the routing table items are implemented in a one-layer tree manner, the forwarding chip table items that need to be operated for each routing operation are greatly reduced, and the best routing operation performance can also be provided.

[0052] In this embodiment, the Bitmap field of the traditional Trie Tree only needs 2 n-1 bit is enough, n is the number of levels of Trie Tree. Figure 4 As shown in the figure, when expand is 0, the Trie Tree used has 5 layers, so the Bitmap field requires 31 bits of space. Figure 3 As shown, when expand is 1, for ease of implementation, Bitmap is as large as possible to a power of 2, i.e. 2 n Bit can add a bit space to the Bitmap to store 32 routes.

[0053] In addition, after the route with a specific prefix length is moved from the original multi-layer tree structure, the original Trie Tree can remain unchanged. If the route with a specific prefix was previously a leaf node, the nodes of other layers are sequentially migrated to the leaves, which can utilize the existing space and improve the storage efficiency of the Trie Tree.

[0054] For further convenience of implementation, the following solution may be adopted: placing the route with expand set on a separate storage unit for implementation.

[0055] S103, implementing routing operations and IP forwarding based on the modified routing table entry.

[0056] To facilitate understanding of the present invention, some specific embodiments are used below to illustrate the application of the present invention.

[0057] In one implementation, the network planning requirement of the user may be a large-scale routing prefix length sequence that the user is concerned about. At this time, the prefix lengths that the user is concerned about may be set to a layer of tree structure through a configuration file to provide a maximum routing specification that meets the user's needs. The configuration file may be in the form of an agreed private definition, or in the form of a standard json file, xml file, or the like.

[0058] For example, if there is a global default prefix plan in the system, a user-defined prefix plan can be superimposed. When there are two prefix plans at the same time, the user-defined prefix is ​​used first; otherwise, the default prefix plan is used to support the ability to store routing table entries of various other mask lengths. In this way, by expanding the TrieTree Bitmap Group plan of IPv4, on the basis of supporting the storage of routes with full mask lengths, all user-planned service routes are implemented as a one-layer tree structure, providing the maximum routing specifications for users' actual services.

[0059] If the network user mainly uses 24, 26, 28, and 32 mask lengths for IPv4 routing, and hopes to provide the maximum routing specification requirements based on the mask length sequence, the actual user IPv4 routing specification definition in Table 3 can be obtained by parsing the user specification requirements based on the Trie Tree BitmapGroup planning of the global IPv4 routing in Table 2.

[0060]

[0061] In another implementation, if the user's routing pattern cannot be known in advance, the routing compression mechanism can be started based on the statistical analysis of the routing. After the routing space utilization reaches a certain set threshold, for example, when the routing table entry space utilization reaches 80%, a large number of routes with specific prefixes with low storage efficiency can be stored using a one-layer Trie Tree solution.

[0062] In summary, based on the one-layer tree structure adopted in this embodiment, since all routing table items are placed in leaf nodes, each time a routing operation is performed, the number of forwarding chip table items added or deleted for each routing table item is effectively reduced, thereby improving the efficiency of routing operations.

[0063] Furthermore, if a batch operation interface is supported, for multiple entries belonging to the same Trie Tree Bitmap Group, only one member needs to be operated, which can further improve the operation efficiency of the routing entries.

[0064] Taking the operation of a single Trie Tree table entry as an example, the route with a mask length of 16 is placed from the root node to the leaf node. At most, 16 operations of writing the forwarding chip table can be compressed into 1 table writing operation, which can theoretically improve the operation performance by 16 times.

[0065] It should be noted that, although the above description is made by taking the management of IPv4 as an example, the solution of the present invention is also applicable to the management of IPv6 routing, which will not be elaborated herein.

[0066] See also Figure 5 The second embodiment of the present invention further provides an efficient management device for routing table entries, which includes:

[0067] The demand acquisition unit 210 is used to acquire the network planning demand of the user;

[0068] The modification unit 220 is used to modify the Trie Tree Bitmap Group plan according to the network planning requirements, and implement the corresponding routing table items in a one-layer tree structure; wherein, in the one-layer tree structure, all Bitmap fields are used to store routes with a prefix length;

[0069] The forwarding unit 230 is used to implement routing operations and IP forwarding based on the modified routing table entries.

[0070] The third embodiment of the present invention further provides an efficient management device for routing table entries, which includes a memory and a processor. The memory stores a computer program, and the computer program can be executed by the processor to implement the efficient management method for routing table entries as described above.

[0071] The fourth embodiment of the present invention further provides a computer-readable storage medium storing a computer program, wherein the computer program can be executed by a processor of a device where the computer-readable storage medium is located to implement the efficient management method of routing table items as described above.

[0072] In several embodiments provided in the embodiments of the present invention, it should be understood that the disclosed apparatus and method can also be implemented in other ways. The apparatus and method embodiments described above are merely schematic. For example, the flowcharts and block diagrams in the accompanying drawings show the possible architecture, functions and operations of the apparatus, method and computer program product according to multiple embodiments of the present invention. In this regard, each box in the flowchart or block diagram can represent a module, a program segment or a part of a code, and the module, program segment or a part of the code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flowchart, and the combination of boxes in the block diagram and / or flowchart can be implemented with a dedicated hardware-based system that performs a specified function or action, or can be implemented with a combination of dedicated hardware and computer instructions.

[0073] In addition, the functional modules in the various embodiments of the present invention may be integrated together to form an independent part, or each module may exist independently, or two or more modules may be integrated to form an independent part.

[0074] If the function is implemented in the form of a software function module and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art or the part of the technical solution can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions to enable a computer device (which can be a personal computer, an electronic device, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program code. It should be noted that in this article, the term "include", "include" or any other variant thereof is intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements includes not only those elements, but also includes other elements that are not explicitly listed, or also includes elements inherent to such process, method, article or device. Without more constraints, an element defined by the phrase "comprising a..." does not exclude the existence of other identical elements in the process, method, article or apparatus comprising the element.

[0075] The terms used in the embodiments of the present invention are only for the purpose of describing specific embodiments, and are not intended to limit the present invention. The singular forms "a", "said" and "the" used in the embodiments of the present invention and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

[0076] It should be understood that the term "and / or" used in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0077] The word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining" or "in response to detecting", depending on the context. Similarly, the phrases "if it is determined" or "if (stated condition or event) is detected" may be interpreted as "when it is determined" or "in response to determining" or "when detecting (stated condition or event)" or "in response to detecting (stated condition or event)", depending on the context.

[0078] The "first\second" mentioned in the embodiments is only to distinguish similar objects, and does not represent a specific order for the objects. It is understandable that the "first\second" can be interchanged with the specific order or sequence where permitted. It should be understood that the objects distinguished by "first\second" can be interchanged where appropriate, so that the embodiments described herein can be implemented in an order other than those illustrated or described herein.

[0079] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An efficient management method for routing table entries, characterized in that: include: Obtain users' network planning requirements; According to the network planning requirements, the Trie Tree Bitmap Group planning is modified, and the corresponding routing table items are implemented in a one-layer tree structure; wherein, in the one-layer tree structure, all Bitmap fields are used to store routes with a prefix length; in the Trie Tree Bitmap Group planning, a one-layer tree structure or a multi-layer tree structure is determined by setting a specific field; when the specific field is set, a one-layer tree structure is adopted, and when the specific field is left blank, a multi-layer tree structure is adopted; the routes with the specific fields set are implemented on a separate storage unit; in the multi-layer tree structure, the number of bits of the Bitmap field is 2 n -1 bit, n is the number of levels in the multi-layer tree structure; in a tree structure with one layer, the number of bits in the Bitmap field is 2 n Bit; Routing operations and IP forwarding are implemented based on the modified routing table entries.

2. The efficient management method for routing table entries according to claim 1, characterized in that: By superimposing a user-defined prefix plan on the global default prefix plan, the user-defined prefix plan is used to record the network planning requirements input by the user; During loading, if it is determined that a user-defined prefix plan exists, the user-defined prefix plan is used by default; otherwise, the global default prefix plan is used.

3. The efficient management method for routing table entries according to claim 2, characterized in that: The user's network planning requirement is a route with a predetermined mask length that is customized by the user.

4. The efficient management method for routing table entries according to claim 2, characterized in that: The network planning requirement of the user is the routing space utilization rate; wherein, after the routing space utilization rate reaches a set threshold, the routing compression mechanism is started to store a large number of routes with low storage efficiency and specific prefixes using a one-layer tree structure.

5. An efficient management device for routing table entries, characterized in that: include: A demand acquisition unit, used to acquire the user's network planning requirements; A modification unit is used to modify the Trie Tree Bitmap Group plan according to the network planning requirements, and implement the corresponding routing table items in a one-layer tree structure; wherein, in the one-layer tree structure, all Bitmap fields are used to store routes with a prefix length; in the Trie Tree Bitmap Group plan, a one-layer tree structure or a multi-layer tree structure is determined by setting a specific field; when the specific field is set, a one-layer tree structure is adopted, and when the specific field is left blank, a multi-layer tree structure is adopted; the route with the specific field set is implemented on a separate storage unit; in the multi-layer tree structure, the number of bits of the Bitmap field is 2 n -1 bit, n is the number of levels in the multi-layer tree structure; in a tree structure with one layer, the number of bits in the Bitmap field is 2 n Bit; The forwarding unit is used to implement routing operations and IP forwarding based on the modified routing table entries.

6. An efficient management device for routing table entries, characterized in that: It comprises a memory and a processor, wherein the memory stores a computer program, and the computer program can be executed by the processor to implement the efficient management method of routing table items as claimed in any one of claims 1 to 4.

7. A computer-readable storage medium, characterized in that: A computer program is stored, and the computer program can be executed by a processor of the device where the computer-readable storage medium is located to implement the efficient management method of routing table items as described in any one of claims 1 to 4.

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