WO2013078644A1

WO2013078644A1 - Route prefix storage method and device and route address searching method and device

Info

Publication number: WO2013078644A1
Application number: PCT/CN2011/083242
Authority: WO
Inventors: 胡睿; 郑远明; 翟素平; 王小忠; 龚钧; 陈洪飞
Original assignee: 华为技术有限公司
Priority date: 2011-11-30
Filing date: 2011-11-30
Publication date: 2013-06-06
Also published as: CN103404092A; CN103404092B

Abstract

Provided are a route prefix storage method and device and route address searching method and device, the storage method comprising: establishing a path compression tree according to a route prefix to be stored, and dividing the path compression tree into one or more sub-trees; setting position domain information for each node of each sub-tree, the position domain information carrying the path length and the path from the parent node of a node to the node, a routing identifier identifying whether the node has a next hop address, and a sub-node identifier identifying whether the node has a sub-node; according to the sequence of the divided sub-tree layers, sequentially storing in the sub-tree storage space of each sub-tree the position domain information of all nodes of each sub-tree as well as the first address pointer of the address storage space pointed to by each sub-tree and used to successively store the next hop address. The technical solution of the present invention increases the routing capacity of a sparse big tree.

Description

Route prefix storage method, device and routing address searching method and device

The present invention relates to a network communication technology, and in particular, to a route prefix storage method, a device, and a route address searching method and apparatus. Background technique

The Internet Engineering Task Force (IETF) introduced an address structure called Classless Inter-Domain Routing (CIDR) in 1993. Although CIDR is only a temporary solution to prevent the exhaustion of address space, it is this technology that forms the basis of the current actual route lookup table. In CIDR, an IP network is represented by a prefix, which is represented by a combination of an IP address and a mask identifying its valid bits. The CIDR allows the router to perform route aggregation. That is, the routing table entries of the same size, two adjacent subnets in the address space, and the same route are merged into one path, and only one entry is occupied in the routing table. The CIDR avoids the excessive exhaustion of the network address and the rapid expansion of the routing entries of the backbone routers, but at the same time, the length of the network address prefix can be any value, and the longest prefix match search must be performed when performing route lookup.

At present, all routing table lookup algorithms are weighed in the following three aspects: 1, the routing table query speed, which is mainly determined by the number of accesses to the memory; 2, the memory capacity required by the routing table; 3, insert or delete The difficulty of routing entries.

In view of the above problems, the most promising method in the prior art is to classify the data structure storing the route prefix, the vertices of the small tree (referred to as lifting nodes) are placed in the big tree, and the small tree adopts the path compression tree structure. In the path compression tree, all route prefixes are stored at its leaf nodes. Suppose there are N route prefixes with N leaf nodes and N-1 internal nodes. The path compression tree allows each internal node to contain a "bit position" field, which is used to indicate the bit position corresponding to the branch node below the node, that is, the number of consecutively skipped bits and the value of the skipped bit. The path compression tree compresses the redundant branch chain to a node. It does not need to do continuous bit matching when searching for routes, but can match multiple bits at a time to reach the leaf nodes quickly. The maximum height of the small tree is limited to a fixed value h, and the value of h is related to the specific hardware environment. In the process of adding an entry, if the height of the small tree exceeds h, the small tree is split, and the split small tree vertex is placed in the large tree. Delete In addition to the entry process, the small trees can be merged according to the merged height not greater than h. The specific implementation method of the big tree is not limited, for example: Range Match, B-tree, TCAM, etc., which method can be used depending on the specific hardware implementation. This method has certain advantages in query speed, storage capacity, and update of routing entries. Therefore, it is a promising route storage and lookup scheme.

However, for some sparse trees, the number of route prefixes per small tree in this scheme is generally small, and the number of small trees is limited. Therefore, the routing capacity of the entire tree will be affected. SUMMARY OF THE INVENTION The present invention provides a route prefix storage method, apparatus, and routing address search method and apparatus for improving the routing capacity of a sparse tree.

An aspect of the present invention provides a method for storing a route prefix, including:

Establishing a path compression tree according to the route prefix to be stored, and dividing the path compression tree into one or more small trees according to the size of the small tree storage space, where each small tree includes multiple nodes;

Locating location domain information for each node of each small tree, the location domain information including a path length and a path of a parent node of the node to the node, a route identifier identifying whether the node has a next hop address, and Identifying whether the node has a child node identifier of the child node;

According to the sequence order of the divided small trees, the location domain information of each node of each small tree and each small tree are sequentially pointed to the first address of the address storage space of all the next hop addresses corresponding to the routing prefix continuously. The pointer is stored in the small tree storage space corresponding to each small tree.

An aspect of the present invention provides a route prefix storage device, including:

a small tree partitioning module, configured to establish a path compression tree according to the route prefix to be stored, and divide the path compression tree into one or more small trees according to the size of the small tree storage space, where each small tree includes multiple nodes ;

An information setting module, configured to set location domain information for each node of each small tree, where the location domain information includes a path length and a path of a parent node of the node to the node, and whether the node has a next a route identifier of the hop address and a child node identifier that identifies whether the node has a child node;

a storage module, configured to sequentially follow the order of the number of layers of the small trees, and sequentially all the sections of each small tree The location domain information of the point and the pointer of each small tree to the first address of the address storage space of all the next hop addresses corresponding to the route prefix are stored in the small tree storage space corresponding to each small tree.

Another aspect of the present invention provides a routing address searching method, including:

According to the order of the number of layers of the small tree, starting from the first node of the first layer of the small tree, matching the searched route prefixes according to the location domain information of each node stored in the small tree storage space corresponding to each layer of the small tree; The location domain information includes a path length and a path of the parent node of the node to the node, a route identifier that identifies whether the node has a next hop address, and a child node identifier that identifies whether the node has a child node;

If the node matching the longest match is matched, the pointer to the first address of the address storage space contiguously storing the next hop address and the longest matching node matched to the node storing the next hop address in the small tree storage space of the matching longest matching node are stored. The location of the next hop address of the route prefix is obtained from the address storage space in which the next hop address is continuously stored.

Another aspect of the present invention provides a routing address searching apparatus, including:

a search module, configured to start, according to the layer sequence of the small tree, the first node of the first layer of the small tree, and the route to be searched according to the location domain information of each node stored in the small tree storage space corresponding to each layer of the small tree The prefix field performs a matching search; the location domain information includes a path length and a path of the parent node of the node to the node, a route identifier that identifies whether the node has a next hop address, and a flag indicating whether the node has a child node. Child node identifier;

An obtaining module, configured to match, to the longest prefix node, the pointer and the matching of the first address of the address storage space that continuously stores the next hop address in the small tree storage space of the longest prefix node that is matched to the storage The location of the longest prefix node to which the next hop address of the route prefix is obtained from the address storage space in which the next hop address is continuously stored.

A method and a device for storing a route prefix provided by an aspect of the present invention, by storing a route identifier that identifies whether a node has a next hop address, and not storing the next hop address of the node directly, the occupied storage space is significantly reduced, which is beneficial to Increase the number of nodes stored in the small tree storage space, increase the number of routing prefixes corresponding to the small trees, and thus improve the routing capacity of the entire large tree, especially for some sparse large trees, The routing capacity of the tree is more effective.

The routing address searching method and device provided by another aspect of the present invention cooperate with the routing prefix storage method and apparatus provided by the embodiment of the present invention, according to the layer sequence of the small tree, according to the small tree of each layer The location domain information of each node in the corresponding small tree storage space is searched for the route prefix to be searched, because the next hop address corresponding to the node is not stored in each small tree storage space, but the storage node has the next hop address. The route identifier increases the number of nodes stored in each small tree storage space, so that one search can find more bits, which improves the search speed and efficiency. BRIEF DESCRIPTION OF THE DRAWINGS In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, a brief description of the drawings used in the embodiments or the prior art description will be briefly described below. The drawings are some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without any creative work.

1A is a flowchart of a method for storing a route prefix according to an embodiment of the present invention;

FIG. 1B is a schematic structural diagram of a path compression tree established by a route prefix and a divided small tree according to an embodiment of the present invention;

2 is a flowchart of a method for storing a route prefix according to another embodiment of the present invention;

FIG. 3 is a flowchart of a routing address searching method according to an embodiment of the present invention;

4A is a schematic structural diagram of a route prefix storage device according to an embodiment of the present invention; FIG. 4B is a schematic structural diagram of a route prefix storage device according to another embodiment of the present invention; FIG. 5 is a schematic diagram of routing address search according to an embodiment of the present invention; Schematic diagram of the structure of the device. detailed description

The technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention. It is a partial embodiment of the invention, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

FIG. 1 is a flowchart of a method for storing a route prefix according to an embodiment of the present invention. As shown in FIG. 1A, the storage method of this embodiment includes:

Step 101: Establish a path compression tree according to the route prefix to be stored, and divide the path compression tree into one or more small trees according to the size of the small tree storage space, and each small tree includes multiple nodes.

In this embodiment, when a certain route prefix needs to be stored, the path is first established according to the route prefix. Path Compressed Trie, that is, according to whether each bit in the route prefix is 0 or 1, the path branches to form a path compression tree. The established path compression tree is a big tree. Then, according to the size of the fixed storage space on the hardware device (for example, 128 bits is a fixed storage space), the established path compression tree is divided into one or more small trees. Among them, the information about each small tree is stored in a fixed size storage space. In this embodiment, a storage space of a fixed size is referred to as a small tree storage space, which means that each small tree storage space corresponds to a small tree.

In this embodiment, some route prefixes are taken as an example, a path compression tree is established according to the route prefixes, and the established path compression tree is divided into three small trees, and the division result is shown in FIG. 1B. As shown in 1B, the three small trees are small tree 1, small tree 2 and small tree 3. Each small tree consists of multiple nodes. In addition, as shown in Fig. 1B, the top nodes of the small tree 2 and the small tree 3 are child nodes of a certain node in the small tree 1. According to the "parent-child relationship" of the nodes between the small trees, the divided small trees can be layered, and the parent nodes of the top nodes are from the small trees of the small trees in the same layer as one layer. Taking FIG. 1B as an example, the small tree 1 is the first layer, and the parent nodes of the top nodes of the small tree 2 and the small tree 3 are all from the small tree 1, so the small tree 2 and the small tree 3 are the second layer. The route prefix included in Figure 1B is shown in Table 1.

Table 1

Step 102: Set location domain information for each node of each small tree, where the location domain information includes a path length and a path of the parent node of the node to the node, and a route identifier that identifies whether the node has a next hop address. Identifies whether the node has a child node ID of the child node.

After dividing each small tree, set location domain information for each node in each small tree. The location domain information of each node includes: the path length and path, the identifier of the parent node of the node to the node Whether the node has a route identifier of the next hop address and a child node identifier that identifies whether the node has a child node.

Each node corresponds to a route prefix. The route prefix may have a next hop address or a next hop address. Therefore, in this embodiment, the route identifier is used to indicate whether the node has a next hop address. For example, the route identifier can be encoded by using 1 bit. If the route prefix corresponding to the node has a next hop address, the route identifier is represented by 1 (or the route identifier is 1); if the route prefix corresponding to the node If there is no next hop address, the route ID is represented by 0 (or the route ID is 0). For another example, the route identifier may be encoded by using 1 bit. If the route prefix corresponding to the node has a next hop address, the route identifier is represented by 0 (or the route identifier takes a value of 0); if the route corresponding to the node If the prefix does not have a next hop address, the route ID is represented by 1 (or the route ID is 1). In addition, in addition to encoding the route identifier using 1 bit, 2 bits, 3 bits, or the like can be used. For example, the route identifier is encoded by using 2 bits. If the route prefix corresponding to the node has a next hop address, the route identifier is represented by 01 (or the route identifier is 01); if the route prefix corresponding to the node is not One-hop address, the route identifier is represented by 00 (or the route identifier takes the value 00). The use of "01" and "00" for route IDs is just an example and can be other values. As shown in Fig. 1B, the black node represents the node with the next hop address, and the hollow node represents the node without the next hop address.

It is explained here that encoding the route identifier by using 1 bit is a preferred implementation manner, which occupies less storage space and has the advantage of saving storage space.

Compared with the prior art, this embodiment does not directly store the next hop address corresponding to each node, but stores a route identifier. The routing identifier of this embodiment is generally smaller than the next hop address, so the storage space occupied by the small hop is relatively small, which increases the number of small trees that can be stored in the small tree storage space, thereby improving the storage capacity of the entire large tree.

Among them, each node has a maximum of 2 child nodes, which are respectively recorded as the left child node and the right child node. In practical applications, a node may have only a left child node, or only a right child node, or any child node, or both a left child node and a right child node. In this embodiment, the child node identifier is used to identify the case where the node has child nodes. For example, the child node identification can be encoded using 2 bits. One way to encode the child node identifier using 2 bits is: If the node has no child nodes, the child node identifier is represented by 00; if the node has only one left child node, the child node identifier is represented by 10; if the node has only one right Child node, child node ID is 01; if node is There are left child nodes and right child nodes, and the child node identifier is represented by 11. Another way to encode the child node identifier using 2 bits is: If the node has no child nodes, the child node identifier is represented by 11; if the node has only one left child node, the child node identifier is represented by 10; if the node has only one node The right child node, the child node identifier uses 01; if the node has both the left child node and the right child node, the child node identifier is represented by 00.

In addition, in addition to encoding the child node identifier using 2-bit, it is also possible to use 3 bits, 4 bits, or the like. For example, one way to encode a child node identifier using 3-bit is: If the node has no child nodes, the child node identifier is represented by 000; if the node has only one left child node, the child node identifier is represented by 100; There is a right child node, the child node identifier is 001; if the node has both a left child node and a right child node, the child node identifier is represented by 111. But not limited to this type of coding.

This embodiment uses the child node identifier to identify the child node of a node, and does not use the pointer pointer to identify it as in the prior art. The storage child node identifier has the advantage of being simple and easy to implement compared with the pointer.

For a node, the path length and path of the node's parent node to that node can be directly represented by its actual value.

Step 103: sequentially, in order of the number of layers of the divided small trees, sequentially, the location domain information of each node of each small tree and each small tree point to the address storage space of all next hop addresses corresponding to the route prefix continuously. The pointer of the address is stored in the small tree storage space corresponding to each small tree.

After setting the location domain information for each node of each small tree, according to the order of the number of layers of the divided small trees, for example, according to the order of the lower layer and then the upper layer, the information about each tree is sequentially stored in each tree. The small tree corresponds to the small tree storage space. The information about each small tree mainly includes: location domain information of all the nodes in the small tree and the address storage space of the next hop address corresponding to the route prefix to be stored in the tree. Pointer to the address. That is, for a small tree, the location information of all the nodes in the small tree and the small tree point to the first address of the address storage space of all the next hop addresses corresponding to the route prefix to be stored continuously. The pointers are stored in the small tree storage space corresponding to the small tree.

The location domain information of each node is used to perform lookup matching with the route prefix when performing route prefix lookup. And the pointer to the first address of the address storage space is used to find the node with the longest prefix matching in the route prefix searching process, and obtain the next node of the node with the longest prefix matching. Jump address.

In this embodiment, by storing the route identifier that identifies whether the node has the next hop address, and not directly storing the next hop address of the node, the occupied storage space is significantly reduced, which is beneficial to improving storage of the small tree storage space. The number of nodes increases the number of route prefixes corresponding to the small tree, thereby increasing the routing capacity of the entire tree. In particular, for some sparse large trees, since the number of small trees is limited, this embodiment improves the routing capacity of the entire tree by increasing the number of routing prefixes corresponding to each small tree.

FIG. 2 is a flowchart of a method for storing a route prefix according to another embodiment of the present invention. As shown in FIG. 2, the storage method of this embodiment includes:

Step 201: Establish a path compression tree according to the route prefix to be stored, and divide the path compression tree into one or more small trees according to the size of the small tree storage space, and each small tree includes multiple nodes.

The execution body of this embodiment may be a route prefix storage device such as a router or a switch. To simplify the description, the route prefix storage will be omitted later.

This step 201 can be referred to the description of step 101.

Step 202: Determine whether the number of layers of the divided small tree is less than or equal to a preset layer threshold; if the determination result is yes, go to step 203; if the judgment result is no, go to step 206.

Generally, when the number of layers of the small tree divided by the path compression tree is greater than a certain value, it indicates that the path compression tree is dense; if the number of layers of the small tree divided by the path compression tree is less than or equal to the value, the path compression tree is indicated. More sparse. This embodiment defines this value as the layer number threshold. The size of the layer threshold depends on the storage capacity of the route prefix storage device. For example, for a route prefix storage device with a small tree storage space of 128 bits, the corresponding layer threshold is generally 3 layers.

This embodiment mainly solves the problem that the path compression tree is sparse, and solves the problem that the path compression tree cannot increase the overall capacity due to the limitation of the number of small trees in the sparse case.

Therefore, in this embodiment, after the small tree is divided, it is determined whether the path compressed tree established according to the route prefix to be stored is sparse by judging the number of layers of the divided small trees. As shown in FIG. 1B, the path compression tree divides three small trees into two layers. If the number of layers is 3, the path compression tree shown in Figure 1B is sparse.

Step 203: Set location domain information for each node of each small tree, where the location domain information includes a path length and a path of the parent node of the node to the node, and a route identifier that identifies whether the node has a next hop address. Identifies whether the node has a child node ID of the child node. When it is judged that the path compression tree is sparse, the location domain information is set for each node of each small tree. The location domain information of each node includes: a path length and a path of the parent node of the node to the node, a route identifier that identifies whether the node has a next hop address, and a child node identifier that identifies whether the node has a child node.

Each of the nodes corresponds to a route prefix. The route prefix may have a next hop address or a next hop address. Therefore, in this embodiment, the route identifier is used to indicate whether the node has a next if mega address.

Among them, each node has a maximum of 2 child nodes, which are respectively recorded as the left child node and the right child node. In practical applications, a node may have only a left child node, or only a right child node, or any child node, or both a left child node and a right child node. In this embodiment, the child node identification is used to identify the case where the node has child nodes.

For other descriptions of this step 203, refer to the description of step 102, and details are not described herein again. Step 204: sequentially, in order of the number of layers of the divided small trees, sequentially, the location domain information of all nodes of each small tree and each small tree point to the address storage space of all next hop addresses corresponding to the route prefix continuously. The pointer of the address is stored in the small tree storage space corresponding to each small tree.

After setting the location domain information for each node of each small tree, according to the order of the number of layers of the divided small trees, for example, according to the order of the lower layer and then the upper layer, the information about each tree is sequentially stored in each tree. The small tree corresponds to the small tree storage space.

In this embodiment, the related information of each small tree mainly includes: location domain information of all nodes in the small tree, and the small tree points to consecutively store addresses of all next hop addresses corresponding to the route prefix to be stored. A pointer to the first address of the storage space, and a pointer to the d, the first address of the tree storage space corresponding to the next layer of the small tree. That is, for a small tree, not only the location information of all the nodes in the small tree and the first address of the address storage space of all the next hop addresses corresponding to the route prefix to be stored are consecutively stored in the small tree. The pointer is stored in the small tree storage space corresponding to the small tree, and the current layer small tree needs to point to the pointer of the first address of the small tree storage space corresponding to the next small tree, and is stored in the small layer corresponding to the current layer small tree. Tree storage space.

In this embodiment, the related information of the small trees included in each layer is continuously stored. This storage mode can save storage space and facilitate routing address lookup. Since the size of the small tree storage space corresponding to each small tree is fixed, when the routing address is searched, the current layer small tree points to the pointer of the first address of the small tree storage space corresponding to the next small tree, and according to Small tree storage space The size of the address offset can find the d, tree storage space corresponding to each small tree in the next layer. In addition, the current layer small tree points to the pointer of the first address of the small tree storage space corresponding to the next small tree and the size of the small tree storage space, and the child node and the child node corresponding to the parent node in the next layer may also be found. Small tree storage space.

The location domain information of each node is used to perform lookup matching with the route prefix when performing route prefix lookup. The pointer to the first address of the address storage space is used to obtain the next hop address of the node matching the longest prefix when the node with the longest prefix matching is found in the route prefix lookup process.

Step 205: Store all next hop addresses corresponding to the route prefix into the address storage space, and end the storage operation.

In this embodiment, in addition to storing the location domain information of each node in the path compression tree established by the route prefix into the corresponding small tree storage space, all next hop addresses corresponding to the route prefix are continuously stored to the address. In storage space. This way of storing the next hop address continuously saves storage space.

Step 206: Store according to the storage manner of the existing path compression tree.

If the path compression tree established according to the route prefix to be stored is relatively dense, the storage method of the existing path compression tree may be stored.

The storage mode of the existing path compression tree is not described in detail in this embodiment.

In this embodiment, when the path compression tree is sparsely judged, when the path compression tree is sparse, the next hop address of the node is not directly stored by storing whether the node has the route identifier of the next hop address. The occupied storage space is significantly reduced, which is beneficial to increase the number of nodes stored in the small tree storage space, improve the compression ratio of the small tree, and increase the number of routing prefixes corresponding to the small tree, thereby improving the entire tree. The routing capacity, especially for some sparse trees, is more effective in improving the routing capacity of the entire tree. In addition, in this embodiment, all the next hop addresses corresponding to the address prefix are separately stored and continuously stored, which is beneficial to save storage space and improve storage space utilization.

FIG. 3 is a flowchart of a method for searching for a route address according to an embodiment of the present invention. As shown in FIG. 3, the searching method in this embodiment includes:

Step 301: According to the layer sequence of the small tree, starting from the first node of the first layer of the small tree, according to the location domain information of each node stored in the small tree storage space corresponding to each layer of the small tree, the method is to be searched. The route prefix performs a matching search; the location domain information includes: a path length and a path of the parent node of the node to the node, a route identifier that identifies whether the node has a next hop address, and a child that identifies whether the node has a child node Node ID.

The execution subject of this embodiment is a routing address searching device, such as a router or a switch. To simplify the description, the routing address lookup device will be omitted.

The routing address searching method in this embodiment is adapted to the routing prefix storage method provided in the foregoing embodiment. The routing address searching method in this embodiment is implemented on the basis of the routing prefix storage method provided in the foregoing embodiment.

Specifically, in the routing space, the number of layers of the small tree that has been divided according to the route prefix to be stored is pre-stored, and the location domain information of each small tree is stored in the corresponding small tree storage space. The small tree storage space is a storage space with a fixed size in the routing space.

When a route prefix is received and the next hop address corresponding to the route prefix needs to be queried, the first node of the first layer of the small tree (only one small tree) stored in the routing space starts, according to each layer 'J The tree corresponding to the 'j, the location domain information of each node stored in the tree storage space is matched and searched for the route prefix to be searched.

The location domain information of each node includes: a path length and a path of the parent node of the node to the node, a route identifier that identifies whether the node has a next hop address, and a child node identifier that identifies whether the node has a child node.

The process of performing matching matching on the route prefix to be searched according to the location domain information of each node in the small tree storage space corresponding to each small tree includes:

When the current node is queried, it is determined whether the path of the current node's parent node to the current node stored in the d, tree storage space of the current node is consistent with the current matching part of the route prefix. If the judgment result is inconsistent, indicating that an error occurs, the search for the route prefix is ended. If the judgment result is consistent, indicating that the matching is correct, it continues to determine whether the current node has a next hop address according to the routing identifier of the current node stored in the small tree storage space where the current node is located. For example, if the route ID of the current node is not 1, it indicates that the current node has a next hop address. If the route ID of the current node is 0, it indicates that the current node does not have a next hop address. If the current node has a next hop address, the location of the current node is recorded and the next hop address is identified. The location of the current node is the part of the route prefix that is currently matched.

In addition, in the case where the judgment result is consistent, it is also stored according to the small tree where the current node is located. The child node identifier of the current node stored in the space determines whether the current node has child nodes. For example, if the child node ID of the current node is 00, the current node has no child nodes; if the child node ID of the current node is 10, the current node has only the left child node; if the child node of the current node is queried The identifier is 01, indicating that the current node has only the right child node; if the child node identifier of the current node is 1 1 , it indicates that the current node has both the left child node and the right child node. If the current node has no children, the search for the route prefix is ended. If the current child has child nodes, continue to query the child nodes. Specifically, if the current node has only the left child node, the left child node is directly queried; if the current node has only the right child node, the right child node is directly queried; if the current child node has both the left child node and the right child node Then, the left child node may be queried first, and when the left child node fails to query, the right child node is queried; or the right child node may be queried first, and when the right child node fails to query, the left child node is queried.

This embodiment performs matching according to the longest prefix matching principle.

Step 302: Determine whether the route prefix matches the longest prefix node. If the judgment result is yes, go to step 303. If the judgment result is no, go to step 304.

When the match is over, determine whether the route prefix matches the longest prefix node. The longest prefix node is a node with a next hop address, and the matching length of the longest prefix node is relative.

If the node with the longest prefix and the next hop address is matched, step 303 is performed; if the node with the next hop address is not matched, indicating that the matching fails, step 304 is performed, that is, the operation ends.

Step 303: According to the location of the first address of the address storage space that points to the consecutive storage of the next hop address and the location of the matched longest prefix node in the small tree storage space of the longest prefix node that is matched, from the continuous storage to the next The next hop address of the route prefix is obtained in the address storage space of the hop address, and step 304 is performed.

When the node with the longest prefix and the next hop address is matched, the continuous address is found according to the pointer to the first address of the address storage space of the longest prefix node that stores the matching last storage address of the next hop address. The first address of the address storage space where the next hop address is stored. Then, the relative position of the next hop address corresponding to the longest prefix matching node in the address storage space is determined according to the location of the longest prefix matching node, thereby obtaining the next hop address.

In this embodiment, all next hop addresses are continuously stored in the address storage space. Place The address storage space described is independent of each small tree storage space.

Step 304, ending the operation.

In this embodiment, based on the route prefix storage method provided in the foregoing embodiment, the route prefix to be searched according to the location domain information of each node in the small tree storage space corresponding to each layer of the small tree is performed according to the layer sequence of the small tree. Find. Since the next hop address corresponding to the node is not stored in each small tree storage space, but the storage node has the route identifier of the next hop address, the node information stored in each small tree storage space is increased, so that once Finding can find more bits, improving the speed and efficiency of the search.

FIG. 4 is a schematic structural diagram of a route prefix storage apparatus according to an embodiment of the present invention. As shown in FIG. 4A, the apparatus of this embodiment includes: a small tree dividing module 41, an information setting module 42, and a storage module 43.

The small tree division module 41 is configured to establish a path compression tree according to the route prefix to be stored, and divide the path compression tree into one or more small trees according to the size of the d and the tree storage space, where each tree is j Includes multiple nodes. The information setting module 42 is connected to the small tree dividing module 41, and is configured to set location domain information for each node of each small tree divided by the small tree dividing module 41, where the location domain information includes the parent node of the node to the node The path length and path of the node, the route identifier that identifies whether the node has a next hop address, and the child node identifier that identifies whether the node has a child node. The storage module 43 is connected to the information setting module 42 for sequentially, in order of the number of layers of the divided small trees, sequentially, the location domain information of all the nodes of each small tree and each small tree point to all the corresponding storage prefixes. A pointer to the first address of the address storage space of the one-hop address is stored in the small tree storage space corresponding to each small tree.

The function modules of the route prefix storage device in this embodiment can be used to execute the flowchart of the route prefix storage method shown in FIG. 1A. The specific working principle is not described here. For details, refer to the description of the method embodiment.

The route prefix storage device of the present embodiment stores the route identifier of the node with the next hop address, and does not directly store the next hop address of the node, and the occupied storage space is significantly reduced, which is beneficial to improving the small tree storage. The number of nodes stored in the space increases the number of route prefixes corresponding to the small tree, thereby increasing the routing capacity of the entire tree. Especially for some sparse trees, because the number of small trees is limited, this embodiment improves the routing capacity of the entire tree by increasing the number of routing prefixes corresponding to each small tree.

FIG. 4B is a schematic structural diagram of a route prefix storage apparatus according to another embodiment of the present invention. Real The embodiment is implemented based on the embodiment shown in FIG. 4A. As shown in FIG. 4B, the information setting module 42 of the present embodiment includes: a first setting unit 421, a second setting unit 422, and a third setting unit 423.

The first setting unit 421 is connected to the small tree dividing module 41 and the storage module 43 for encoding, for each node, the child node identifier by using 2 bits, if the node has no child nodes, the child The node identifier is represented by 00. If the node has only one left child node, the child node identifier is represented by 10. If the node has only one right child node, the child node identifier is represented by 01, if the node There are both a left child node and a right child node, and the child node identifier is represented by 11.

The second setting unit 422 is connected to the small tree dividing module 41 and the storage module 43 for encoding, for each node, the routing identifier by using 1 bit. If the node has a next hop address, the routing identifier Indicated by 1, if the node does not have a next hop address, the routing node is represented by 0.

The third setting unit 423 is connected to the small tree dividing module 41 and the storage module 43 for setting a path length and a path of the parent node of the node to the node.

Further, the storage module 43 is further configured to continuously store all the next hop addresses corresponding to the routing prefix into the address storage space.

Further, the storage module 43 is further configured to point the current layer small tree to the pointer of the first address of the small tree storage space corresponding to the next layer of the small tree, and store the pointer to the small tree storage space corresponding to the current layer small tree.

The route prefix storage device of this embodiment further includes: a determining module 44.

The determining module 44 is connected to the small tree dividing module 41 and the information setting module 42 for determining whether the number of layers of the divided small tree is determined before the information setting module 42 sets the location domain information for each node of each small tree. If the result of the determination is yes, the trigger information setting module 42 sets the location domain information for each node of each small tree.

The foregoing functional units or modules may be used to perform the corresponding processes in the method for storing the route prefix shown in FIG. 1A or FIG. 2, and the specific working principles are not described herein again. For details, refer to the description of the method embodiments.

The routing prefix storage device in this embodiment performs the densification judgment on the path compression tree. When the path compression tree is sparse, the storage node identifies whether there is a route identifier of the next hop address, and does not directly store the next node of the node. The hop address, the occupied storage space is significantly reduced, which is beneficial to increase the number of nodes stored in the small tree storage space, improve the compression rate of the small tree, and increase the number of routing prefixes corresponding to the small tree, thereby improving the number of routing prefixes. The routing capacity of the entire tree, especially for some sparse For the big tree, the improvement of the routing capacity of the whole tree is more obvious. In addition, the route prefix storage device of the embodiment saves the storage space and improves the utilization of the storage space by separately storing and continuously storing all the next hop addresses corresponding to the address prefix.

FIG. 5 is a schematic structural diagram of a routing address searching apparatus according to an embodiment of the present invention. As shown in FIG. 5, the routing address searching apparatus of this embodiment includes: a searching module 51 and an obtaining module 52.

The searching module 51 is configured to, according to the layer sequence of the small tree, start from the first node of the first layer of the small tree, and treat the location domain information of each node stored in the small tree storage space corresponding to each layer of the small tree. The searched route prefix performs a matching search; the location domain information includes a path length and a path of the parent node of the node to the node, a route identifier that identifies whether the node has a next hop address, and a flag indicating whether the node has a child node. Child node ID.

The obtaining module 52 is connected to the searching module 51, and is configured to match the longest prefix node in the searching module 51, and according to the address storage space of the small tree storage space storing the matched longest prefix node to the consecutive storage of the next hop address The pointer of the first address and the location of the longest prefix node that is matched are obtained, and the next hop address of the route prefix is obtained from the address storage space in which the next hop address is continuously stored.

The searching module 51 performs a matching search process on the routing prefix to be searched according to the location domain information of each node stored in the small tree storage space. The searching module 51 determines that the parent node of the current node stored in the small tree storage space is current. Whether the path of the node is consistent with the current matching part of the routing prefix; if they are consistent, the searching module 51 determines whether the current node has a next hop address according to the routing identifier of the current node in the small tree storage space, if the current node has a next The hop address records the location of the current node and identifies the next hop address, and determines whether the current node has a child node according to the child node identifier in the small tree storage space. If the current node has a child node, continue to query the current node's child. Node; If the current node does not have a child node, the search for the route prefix ends. If not, the lookup module 51 ends the lookup of the route prefix.

The function modules of the routing address lookup module in this embodiment can be used to perform the process of the routing address searching method shown in FIG. 3. The specific working principle is not described here. For details, refer to the description of the method embodiment.

The route address locating device of the embodiment is matched with the route prefix storage device provided in the foregoing embodiment, and according to the layer sequence of the small tree, according to the location domain information of each node in the small tree storage space corresponding to each layer of the small tree The discovered route prefix is searched, because each small tree storage space no longer stores the next hop address corresponding to the node but the storage node has the route identifier of the next hop address, and the node stored in each small tree storage space Increased information, so that a search can find more Multi-bit, improved search speed and efficiency.

A person skilled in the art can understand that all or part of the steps of implementing the above method embodiments may be completed by using hardware related to program instructions, and the foregoing program may be stored in a computer readable storage medium, and the program is executed when executed. The foregoing steps include the steps of the foregoing method embodiments; and the foregoing storage medium includes: a medium that can store program codes, such as a ROM, a RAM, a magnetic disk, or an optical disk.

It should be noted that the above embodiments are only for explaining the technical solutions of the present invention, and are not intended to be limiting; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those skilled in the art that: The technical solutions described in the foregoing embodiments are modified, or some of the technical features are equivalently replaced. The modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

Claim

A method for storing a route prefix, comprising:

2. The route prefix storage method according to claim 1, wherein the setting the location domain information for each node of each small tree comprises:

For each node, the child node identifier is encoded with 2 bits. If the node has no child nodes, the child node identifier is represented by 00, and if the node has only one left child node, the child node identifier Indicated by 10, if the node has only one right child node, the child node identifier is represented by 01, and if the node has both a left child node and a right child node, the child node identifier is represented by 11;

For each node, the route identifier is encoded by 1 bit. If the node has a next hop address, the route identifier is represented by 1. If the node does not have a next hop address, the routing node uses 0. Express

Set the path length and path of the parent node of the node to the node.

The method for storing a route prefix according to claim 1 or 2, further comprising: continuously storing all next hop addresses corresponding to the route prefix into the address storage space.

The method for storing a route prefix according to claim 1 or 2, further comprising: pointing the current layer small tree to a pointer of a first address of the small tree storage space corresponding to the next layer of the small tree, and storing the pointer to the current layer The small tree corresponds to the small tree storage space.

The method for storing a route prefix according to claim 1 or 2, wherein before the location domain information is set for each node of each small tree, the method includes:

Determining whether the number of layers of the divided small tree is less than or equal to a preset layer threshold; As a result, an operation of setting location domain information for each node of each small tree is performed.

A routing address searching method, comprising:

If the longest prefix node is matched, the pointer to the first address of the address storage space that continuously stores the next hop address and the location of the longest prefix node that is matched are stored according to the storage space of the longest prefix node that matches the longest prefix node. The next hop address of the route prefix is obtained from an address storage space in which the next hop address is continuously stored.

The routing address searching method according to claim 6, wherein the matching of the route prefix to be searched according to the location domain information of each node stored in the small tree storage space includes:

Determining whether the path of the parent node of the current node in the small tree storage space to the current node is consistent with the current matching part of the route prefix;

If they are consistent, determine whether the current node has a next hop address according to the route identifier of the current node in the small tree storage space. If the current node has a next hop address, record the current node location and identify the next hop address. And determining, according to the child node identifier in the small tree storage space, whether the current node has a child node; if the current node has a child node, continuing to query the child node; if the current node does not have a child node, ending the routing Lookup of the prefix;

If not, the search for the route prefix is ended.

8. A route prefix storage device, comprising:

An information setting module, configured to set location domain information for each node of each small tree, where the location domain information includes a path length and a path of a parent node of the node to the node, and whether the node has a next a route identifier of the hop address and a child node identifier that identifies whether the node has a child node; a storage module, configured to sequentially store location domain information of all nodes of each small tree and each small tree to address consecutively storing addresses of all next hop addresses corresponding to the routing prefix according to the hierarchical order of the divided small trees. A pointer to the first address of the space is stored in the small tree storage space corresponding to each small tree.

The routing prefix storage device according to claim 8, wherein the information setting module comprises:

a first setting unit, configured to encode the child node identifier by 2 bits for each node, if the node has no child nodes, the child node identifier is represented by 00, if the node has only one left child a node, the child node identifier is represented by 10, if the node has only one right child node, the child node identifier is represented by 01, and if the node has both a left child node and a right child node, the child node identifier Expressed by 1 1;

a second setting unit, configured to encode the route identifier by using 1 bit for each node, if the node has a next hop address, the route identifier is represented by 1, if the node does not have a next hop address The routing node is represented by 0;

And a third setting unit, configured to set a path length and a path of the parent node of the node to the node.

The routing prefix storage device according to claim 8 or 9, wherein the storage module is further configured to continuously store all next hop addresses corresponding to the routing prefix into the address storage space.

The routing prefix storage device according to claim 8 or 9, wherein the storage module is further configured to point the current layer small tree to a pointer of a first address of a small tree storage space corresponding to the next layer of the small tree. , stored in the small tree storage space corresponding to the current layer small tree.

The routing prefix storage device according to claim 8 or 9, further comprising:

a judging module, configured to determine, before the information setting module sets location domain information for each node of each small tree, whether the number of layers of the divided small tree is less than or equal to a preset layer threshold, and if the judgment result is yes The information setting module is triggered to set location domain information for each node of each small tree.

13. A routing address searching device, comprising:

a search module, configured to start from the first node of the first layer of the small tree according to the layer sequence of the small tree, and to find the location domain information of each node stored in the small tree storage space corresponding to each layer of the small tree The route prefix performs a matching search; the location domain information includes a path length and a path of the parent node of the node to the node, a route identifier that identifies whether the node has a next hop address, and a flag indicating whether the node exists. The child node identifier of the node;

The routing address locating device according to claim 13, wherein the searching module is specifically configured to determine whether a path of a parent node of the current node in the small tree storage space to a current node is current with the route prefix. The matched parts are consistent; if they are consistent, determining whether the current node has a next hop address according to the routing identifier of the current node in the small tree storage space, and if the current node has a next hop address, recording the current node location And identifying the next hop address, and determining whether the current node has a child node according to the child node identifier in the small tree storage space; if the current node has a child node, continuing to query the child node; if the current node does not exist The node ends the lookup of the route prefix; if not, ends the lookup of the route prefix.