CN110493129B

CN110493129B - Updating method of backup label path, message forwarding method and device

Info

Publication number: CN110493129B
Application number: CN201910676855.9A
Authority: CN
Inventors: 郭威; 黄李伟; 王伟
Original assignee: New H3C Big Data Technologies Co Ltd
Current assignee: New H3C Big Data Technologies Co Ltd
Priority date: 2019-07-25
Filing date: 2019-07-25
Publication date: 2021-11-09
Anticipated expiration: 2039-07-25
Also published as: CN110493129A

Abstract

The present disclosure relates to the field of network communication technologies, and in particular, to an update method, a packet forwarding method, and an apparatus for a backup label path. The updating method of the backup label path comprises the following steps: acquiring an initial backup label path, wherein the initial backup label path comprises a label value distributed by a PQ node; when a network path corresponding to a locally connected node changes, transmitting address information of a next hop node of the PQ node to the PQ node; receiving a label value of a next hop node fed back by the PQ node; and pushing the received label value into the next layer of the label value distributed by the PQ node for the PQ node, and updating the initial backup label path. When sensing that a network path corresponding to a node connected with the local node changes, requesting the PQ node to send a label value allocated to a next hop node, so that two layers of labels exist in the updated backup label path corresponding to the PQ node, the availability of the backup path can be ensured, and a large amount of flow break during message forwarding is prevented.

Description

Updating method of backup label path, message forwarding method and device

Technical Field

The present disclosure relates to the field of network communication technologies, and in particular, to an update method, a packet forwarding method, and an apparatus for a backup label path.

Background

When the network device forwards the message, the network device includes a backup path in addition to the main path and the standby path. The backup path can be calculated according to a shortest path optimization algorithm, and when a network node fails, the backup path is quickly switched to without waiting for convergence of network equipment. For example, referring to fig. 1, assuming that the traffic path is PE1 → P1 → P2 → PE2, in order to avoid traffic loss due to link failure between P1 and P2, the rlfa (remote lfa) algorithm calculates a PQ node (PQ node is a node in both the extended P space and the Q space, and the PQ node will be the destination of the protection Tunnel), and establishes a label distribution protocol Tunnel (LDP Tunnel) between P1 and the PQ node (P4). When detecting a link failure between the P1 and the P2, the P1 encapsulates the packet into a Multi Protocol Label Switching (MPLS) packet and forwards the packet to the P4, and after receiving the packet, the P4 removes the MPLS Label, re-searches the IP routing table, forwards the packet to the next hop, and finally reaches the destination PE2, thereby implementing fast protection and avoiding traffic loss.

However, when the network path of the backup path fluctuates, the backup path may be unavailable due to the scenario that some combinations affect each other, thereby causing a large amount of current interruption. For example, when IGP synchronization and RLFA coexist, there is a conflicting impact. In particular, since LDP is based on an Interior Gateway Protocol (IGP) optimal route setup Label Switched Path (LSP), traffic forwarding termination may result from the LDP and IGP being out of synchronization. After the LDP IGP synchronization function is started, the IGP can inform a normal overhead value for a link only if the LDP converges on the link, otherwise, the IGP informs the maximum value of the link overhead, so that the link can be seen in the IGP topology. However, in the case that other links are available, IGP will not select the link as the optimal route, so as to ensure that when the device receives the packet, the packet will not be discarded because the LDP LSP on the optimal route is not established.

However, when IGP synchronization and RLFA coexist, it is easy for the protection path to fail to protect. Specifically, the network structure shown in fig. 2 is taken as an example. All links are default overhead, each node enables RLFA, and LDP IGP synchronization is enabled. According to the protocol principle of RLFA, with device No. 4 as an observation point, if it is necessary to form a master/slave to device No. 3, 3.3.3/32, a master path L4 is generated, and a backup path L RLFA generates an LDP TUNNEL that reaches device 1.1.1.1. In addition, in order to prevent packet loss during the back-cut of the service in the network, an LDP IGP synchronization technology is adopted. Subsequently, if the link fluctuation of L2 occurs, that is, the link is UP immediately after DOWN, or some other transmission reasons cause that the

IP layers

1 and 3 cannot reach a moment, the LDP direct-connection neighbor between them vibrates, and at this time, IGP synchronization is triggered, so that packet loss due to switching back of data packets sent from other nodes to 1 after UP of the link is avoided, and after IGP synchronization is triggered, the link overhead of L2 becomes the maximum. When the overhead becomes maximum, the RLFA needs to recalculate the PQ node due to the overhead change in the whole network (i.e. the network topology changes). At this time, the route from 4 to 3.3.3.3/32 can not form FRR any more because the loop-free formula of the route can not be satisfied any more, so that the traffic from 4 to 3.3.3.3/32 can not be protected during the delay period of IGP synchronization, and if L2 is UP again and during the IGP synchronization recovery period, the unexpected fault of L4 occurs again, and the traffic from 4 to 3.3.3.3/32 is not protected, so that the traffic is cut off greatly.

Disclosure of Invention

In view of this, the embodiments of the present disclosure provide an updating method, a message forwarding method, and an apparatus for a backup label path, so as to solve the problem that a backup path is unavailable due to network path fluctuation.

According to a first aspect, an embodiment of the present disclosure provides an update method for a backup label path, including:

acquiring an initial backup label path, wherein the initial backup label path comprises a label value distributed by a PQ node;

when a network path corresponding to a locally connected node changes, transmitting address information of a next hop node of the PQ node to the PQ node;

receiving a tag value of the next hop node fed back by the PQ node; wherein the label value of the next hop node is generated by the PQ node based on address information of the next hop node;

and pushing the received label value into the next layer of the label value distributed by the PQ node for the PQ node, and updating the initial backup label path.

According to the method for updating the backup label path provided by the embodiment of the disclosure, when a network path corresponding to a node connected locally is sensed to be changed, a PQ node is requested to send a label value allocated to a next hop node, so that two layers of labels exist in the updated backup label path corresponding to the PQ node, the first layer of label is the label value allocated to the PQ node, the second layer of label value allocated to the PQ node is the label value allocated to the next hop node, and when the network path is changed through setting of the two layers of label values, the availability of the backup path can be ensured, and a large amount of flow break during message forwarding is prevented.

With reference to the first aspect, in a first implementation manner of the first aspect, the initial backup label path is stored by using a label stack; wherein the pushing the received tag value into a layer below a tag value allocated by the PQ node for the PQ node, includes:

determining the position of a label value distributed by the PQ node for the PQ node in the label stack;

inserting the received tag value into a layer next to the determined position.

With reference to the first aspect, in a second implementation manner of the first aspect, before the step of receiving the tag value of the next hop node fed back by the PQ node, the method further includes:

a step of transmitting an identification bit to the PQ node; and the identification bit corresponds to the address information of the next hop node.

According to the updating method of the backup label path provided by the embodiment of the disclosure, the identification bit is sent to the PQ node, so that the PQ node can distinguish the purpose of locally sending the address information of the next hop node to the PQ node based on the identification bit, the accuracy of the label value fed back by the PQ node is improved, and the reliability of the backup path is further ensured.

With reference to the first aspect, in a third implementation manner of the first aspect, the obtaining a backup label path includes:

acquiring a network path corresponding to a node connected locally;

determining the PQ node based on the network path;

and sending a label request message to the PQ node to obtain the backup label path.

According to the updating method of the backup label path, the backup label path is obtained so as to facilitate subsequent updating of the backup path based on the backup label path, and the problem that the backup path is unavailable due to the fact that the backup label path cannot be obtained under the condition of certain scene conflicts can be avoided.

With reference to the first aspect or any one of the first to third embodiments of the first aspect, in a fourth embodiment of the first aspect, the network path change corresponding to the locally connected node is to trigger IGP synchronization and the LDP session is not timed out.

According to a second aspect, an embodiment of the present disclosure further provides an updating method of a backup label path, including:

receiving address information sent by a source node; wherein the address information is address information of a local next hop node, and the local is a PQ node corresponding to the source node and the next hop node; the address information comprises an identification bit, and the identification bit is used for requesting local allocation of a label value for the next hop node;

allocating a label value to the next hop node based on the address information of the next hop node;

transmitting the label value to the source node.

The method for updating a backup label path provided by the embodiment of the present disclosure includes locally receiving address information of a local next hop node sent by a source node, where the address information carries an identification bit, and locally determining that a label value needs to be allocated to the next hop node at this time by using the identification bit, and then receiving, by a corresponding ground source node, a label value locally allocated to the next hop node, so that two layers of labels may exist in the updated backup label path corresponding to a PQ node, where the first layer of labels is a label value allocated to the PQ node by itself, and the second layer of labels is a label value allocated to the PQ node by itself.

With reference to the second aspect, in a first implementation manner of the second aspect, before the step of receiving address information of a next hop node sent by the source node, the method further includes:

receiving a label request message sent by the source node; wherein, the tag request message carries local address information;

assigning a tag value locally based on the tag request message;

and sending the locally assigned tag value to the source node.

According to the updating method of the backup label path, before the network path fluctuates, the label value is requested to be locally allocated to form the backup label path, so that the backup label path can be updated based on the backup label path in the following process, and the problem that the backup label path is unavailable due to the fact that the backup label path cannot be acquired under the condition of certain scene conflicts can be solved.

According to a third aspect, an embodiment of the present disclosure further provides a packet forwarding method, including:

acquiring a message to be forwarded and a backup label path; the backup label path is formed according to the first aspect of the present disclosure, or the update method of the backup label path described in any embodiment of the first aspect;

packaging the message to be forwarded based on the backup label path to obtain a multi-protocol label switching message;

and forwarding the multi-protocol label switching message to a PQ node.

In the packet forwarding method provided by the embodiment of the present disclosure, two layers of labels may exist in a backup label path corresponding to a PQ node, where the first layer of label is a label value allocated by the PQ node to itself, and the second layer of label value allocated by the PQ node to a next hop node, and when the network path changes (that is, an IP routing table does not exist) due to the two layers of label values, the packet can be forwarded from the PQ node to the next hop node by label forwarding, thereby preventing a large amount of flow break.

According to a fourth aspect, an embodiment of the present disclosure further provides a packet forwarding method, including:

receiving a multi-protocol label switching message; wherein, the multi-protocol label switching message carries a backup label path, and the backup label path is formed according to the second aspect of the present disclosure or the update method of the backup label path in any embodiment of the second aspect;

analyzing the multi-protocol label switching message to obtain the backup label path;

and forwarding the multi-protocol label switching message based on the backup label path.

In the packet forwarding method provided by the embodiment of the present disclosure, because the backup path has two layers of labels corresponding to the PQ node, the backup label path is obtained when the multi-protocol label switching packet is analyzed, and when the packet is forwarded and the IP routing table does not exist, the packet can be forwarded from the PQ node to the next hop node through label forwarding at the PQ node, thereby preventing a large amount of flow break.

According to a fifth aspect, an embodiment of the present disclosure further provides an apparatus for updating a backup label path, including:

the system comprises a first acquisition module, a second acquisition module and a third acquisition module, wherein the first acquisition module is used for acquiring an initial backup label path, and the initial backup label path comprises a label value distributed by a PQ node;

a first sending module, configured to send, to the PQ node, address information of a next hop node of the PQ node when a network path corresponding to a locally connected node changes;

a first receiving module, configured to receive a tag value of the next hop node fed back by the PQ node; wherein the label value of the next hop node is generated by the PQ node based on address information of the next hop node;

and the updating module is used for pressing the received label value into the next layer of the label value distributed by the PQ node for the updating module to update the initial backup label path.

According to a sixth aspect, an embodiment of the present disclosure further provides an apparatus for updating a backup path, including:

a second receiving module, configured to receive address information sent by the source node; the address information is address information of a local next hop node, and the local node is a PQ node corresponding to the source node and the next hop node; the address information also comprises an identification bit, and the identification bit is used for requesting local allocation of a label value for the next hop node;

a label value allocation module, configured to allocate a label value to the next hop node based on the address information of the next hop node;

a second sending module, configured to send the tag value to the source node.

According to a seventh aspect, an embodiment of the present disclosure further provides a packet forwarding apparatus, including:

the second acquisition module is used for acquiring the message to be forwarded and the backup label path; the backup label path is formed according to the first aspect of the present disclosure, or the update method of the backup label path of any one of the first aspect;

the encapsulation module is used for encapsulating the message to be forwarded based on the backup label path so as to obtain a multi-protocol label switching message;

and the first forwarding module is used for forwarding the multi-protocol label switching message to the PQ node.

According to an eighth aspect, an embodiment of the present disclosure further provides a packet forwarding apparatus, including:

a third receiving module, configured to obtain a multi-protocol label switching packet; wherein, the multi-protocol label switching message carries a backup label path, and the backup label path is formed according to the second aspect of the disclosure or the updating method of the backup label path in any one of the second aspects;

the analysis module is used for analyzing the multi-protocol label switching message to obtain the backup label path;

and the second forwarding module is used for forwarding the multi-protocol label switching message based on the backup label path.

According to a ninth aspect, an embodiment of the present disclosure further provides a network device, including:

a memory and a processor, the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the computer instructions to perform the method for updating a backup path according to the first aspect, or any one of the first aspect, or the second aspect, or any one of the second aspect of the present disclosure, or to perform the method for forwarding a packet according to the third aspect or the fourth aspect.

According to a tenth aspect, the embodiments of the present disclosure further provide a computer-readable storage medium, where the computer-readable storage medium stores computer instructions for causing the computer to execute the method for updating a backup path according to the first aspect, or any one of the first aspect, or the second aspect, or any one of the second aspect of the present disclosure, or execute the method for forwarding a packet according to the third aspect or the fourth aspect.

Drawings

In order to more clearly illustrate the embodiments of the present disclosure or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present disclosure, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 is a schematic diagram of a network topology;

FIG. 2 is a schematic diagram of a network topology according to an embodiment of the present disclosure;

FIG. 3 is a flow chart of an update method of a backup label path according to an embodiment of the present disclosure;

FIG. 4 is a flow chart of an update method of a backup label path according to an embodiment of the present disclosure;

FIG. 5 is a flow chart of an update method of a backup label path according to an embodiment of the present disclosure;

FIG. 6 is a flow chart of an update method of a backup label path according to an embodiment of the present disclosure;

FIG. 7 is a flow chart of an update method of a backup label path according to an embodiment of the present disclosure;

FIG. 8 is a flow chart of an update method of a backup label path according to an embodiment of the present disclosure;

fig. 9 is a flow chart of a message forwarding method according to an embodiment of the present disclosure;

fig. 10 is a flow chart of a message forwarding method according to an embodiment of the present disclosure;

fig. 11 is a flow chart of a message forwarding method according to an embodiment of the present disclosure;

fig. 12 is a block diagram of an updating apparatus for a backup label path according to an embodiment of the present disclosure;

fig. 13 is a block diagram of an updating apparatus for a backup label path according to an embodiment of the present disclosure;

fig. 14 is a block diagram of an updating apparatus of a backup tag path according to an embodiment of the present disclosure;

fig. 15 is a block diagram of an updating apparatus of a backup label path according to an embodiment of the present disclosure;

fig. 16 is a block diagram of a structure of a message forwarding apparatus according to an embodiment of the present disclosure;

fig. 17 is a block diagram of a structure of a message forwarding apparatus according to an embodiment of the present disclosure;

fig. 18 is a schematic hardware structure diagram of a network device according to an embodiment of the present disclosure.

Detailed Description

To make the objects, technical solutions and advantages of the embodiments of the present disclosure more clear, the technical solutions of the embodiments of the present disclosure will be described clearly and completely with reference to the drawings in the embodiments of the present disclosure, and it is obvious that the described embodiments are some, but not all embodiments of the present disclosure. All other embodiments, which can be derived by a person skilled in the art from the embodiments disclosed herein without making any creative effort, shall fall within the protection scope of the present disclosure.

Fig. 2 shows a schematic diagram of an application scenario of packet forwarding. In fig. 2, the source node is 4, the destination node is 3, the PQ node is 1, the packet needs to be forwarded from 4 to 3, and when the primary path fails, the packet is forwarded from the backup path, for example, from node 4 to node 1, and node 1 forwards the packet to node 3 by looking up the IP routing table. If L2 fluctuates at this time, node 4 deletes the backup path, resulting in the unavailability of the existing backup path. After deleting the backup path, the node 4 recalculates the path, and the path calculation fails due to the change of the network path, thereby causing the failure of message forwarding and further causing a large amount of flow interruption.

Based on this, the update method of the backup path provided by the embodiment of the disclosure is used for solving the problem that the backup path is unavailable when the network path fluctuates, and the unavailability of the backup path will cause a large amount of flow break. The network path fluctuation is that the temporary change of the network path can be recovered later, and is not the network path change caused by the network modification of the user.

The method for updating the backup path provided by the embodiment of the disclosure can be applied to the situation that the backup path is unavailable due to network path fluctuation in network setting, and does not limit the number of network nodes in the network path. Each network node is able to sense fluctuations in the network path, e.g., sensing whether to fluctuate may be done with whether to trigger IGP synchronization, etc.

In accordance with an embodiment of the present disclosure, there is provided an embodiment of an update method for a backup label path, it should be noted that the steps illustrated in the flowchart of the drawings may be performed in a computer system such as a set of computer executable instructions, and that while a logical order is illustrated in the flowchart, in some cases the steps illustrated or described may be performed in an order different than that herein.

In this embodiment, an updating method of a backup label path is provided, which can be used in the above-mentioned network device, such as a router, a switch, and the like, and fig. 3 is a flowchart of an updating method of a backup label path according to an embodiment of the present disclosure, and as shown in fig. 3, the flowchart includes the following steps:

s11, an initial backup label path is obtained.

The initial backup label path comprises a label value allocated by the PQ node for the initial backup label path.

The initial backup path may be acquired before packet transmission, for example, a RLFA algorithm may be used to calculate a PQ node according to a network path, and a tunnel is established between a source node and the PQ node to form backup next hop protection. When the protection link fails, the flow is automatically switched to a backup path, that is, the source node forwards the packet to the PQ node based on the label value allocated to the source node by the PQ node. This step will be described in detail hereinafter.

S12, it is determined whether or not the network path corresponding to the locally connected node has changed.

When the network path changes, corresponding actions, such as IGP synchronization and the like, may be triggered, so that the source node can monitor in real time whether the network path corresponding to the locally connected node changes. When the network path corresponding to the locally connected node changes, S13 is performed; otherwise, S12 is executed.

For example, referring to fig. 2, node 4 is a source node, and when link L2 fluctuates, node 4 triggers IGP synchronization, so that it can be determined that the network path changes at this time.

S13, the address information of the next hop node of the PQ node is transmitted to the PQ node.

When the source node determines that the network path changes, it sends address information of a next hop node of the PQ node to the PQ node, and the sending of the address information of the next hop node may be based on a request message, that is, the request message carries the address information of the next hop node of the PQ node. For example, the request message may be, but is not limited to, using a label request message.

And S14, receiving the label value of the next hop node fed back by the PQ node.

Wherein the label value of the next hop node is generated by the PQ node based on address information of the next hop node.

Specifically, the PQ node may feed back the label value allocated to the next-hop node to the source node in a reply message, and the label reply may be, but is not limited to, using a label mapping message.

And S15, pushing the received label value into the next layer of the label value allocated by the PQ node to update the initial backup label path.

The initial backup label path obtained by the source node may be a sequence of a plurality of label values, in which the label value assigned by the PQ node for itself is included, and the label value obtained by the source node in S14 is assigned by the PQ node for its next hop node. Therefore, the source node needs to push the tag value obtained in S14 to the layer below the tag value assigned by the PQ node for itself, so as to update the initial backup tag path.

In the method for updating a backup label path provided in this embodiment, when it is sensed that a network path corresponding to a node connected locally changes, a PQ node is requested to send a label value allocated to a next hop node, so that two layers of labels may exist in the updated backup label path corresponding to the PQ node, where the first layer of label is a label value allocated by the PQ node to itself, and the second layer of label value is a label value allocated by the PQ node to its next hop node.

In this embodiment, an updating method of a backup label path is provided, which can be used in the above-mentioned network device, such as a router, a switch, and the like, and fig. 4 is a flowchart of the updating method of the backup label path according to the embodiment of the present disclosure, and as shown in fig. 4, the flowchart includes the following steps:

s21, an initial backup label path is obtained.

The source node obtains the label value allocated by the PQ node to the source node by sending a label request message to the PQ node, thereby forming an initial backup label path. Specifically, the method comprises the following steps:

s211, acquiring a network path corresponding to the locally connected node.

The source node is able to perceive the network path corresponding to the node to which it is connected, i.e. the source node is able to perceive the links between its nearby neighboring nodes.

S212, determine a PQ node based on the network path.

The source node may determine a PQ node based on the perceived network path to establish the backup tunnel.

Taking fig. 1 as an example, the process of determining the PQ node is as follows:

(1) respectively calculating SPF trees taking all neighbors (excluding neighbors passing through protection links) of P1 as roots, wherein a node which is reachable from a root node without passing through a P1 → P2 link in each SPF tree is a P space, and the P spaces of all the neighbors are collected to obtain an expanded P space { PE1, P3, P4 };

(2) calculating a reverse SPF tree with P2 as a root node to obtain a Q space { P2, PE2, P4 };

(3) a node in both the extension P space and the Q space, i.e., a PQ node (P4).

S213, sending a label request message to the PQ node to obtain an initial backup label path.

After determining the PQ node, the source node sends a label request message to the PQ node, and the purpose of the label request message is to obtain a label allocated by the PQ node for the source node so as to obtain an initial backup label path. The initial backup label path is stored in a stack form, that is, the backup label path is attached to the message in a label stack form during the subsequent encapsulation of the message.

S22, it is determined whether or not the network path corresponding to the locally connected node has changed.

Wherein the network path change corresponding to the locally connected node is to trigger IGP synchronization and an LDP session is not timed out.

Taking fig. 2 as an example, when L2 fluctuates, that is, the link is UP immediately after DOWN, or some other transmission reasons make

IP layers

1 and 3 unreachable for a while, and the LDP direct-connection neighbors between them oscillate, an IGP synchronization is triggered at this time. When the IGP synchronization is triggered, the RLFA calculation fails, and the LDP session has not timed out, S23 is executed; otherwise, S22 is executed.

S23, the address information of the next hop node of the PQ node is transmitted to the PQ node.

When topology changes so that PQ node calculation changes and FRR does not exist, at this time, an LDP session established with a PQ node has not timed out, and when there is a remote session which has not timed out due to failure of RLFA calculation but will be timed out later, a source node initiates a label request message of LDP to the PQ node, where the request message indicates a PQ node topology change but needs to maintain a backup route, and an equivalence class (FEC) included in the request message is a set of addresses which cannot be calculated by the backup route due to the RLFA topology change, such as 3.3.3.3/32 for 4 to 1 in fig. 2, and such request message (the request message may be, but not limited to, a label request message).

For the rest, please refer to S13 in the embodiment shown in fig. 3, which is not described herein again.

And S24, sending the identification bit to the PQ node.

And the identification bit corresponds to the address information of the next hop node.

The source node may send the identification bit together with the address information or separately, and only needs to ensure that the identification bit can correspond to the address information of the next hop node.

For example, a reserved bit of the LDP message may be added with an identification bit, and the source node transmits the identification bit together with the address information of the next hop node to the PQ node.

Specifically, the flag functions as: when the network is normal, the source node also sends a label request message to the PQ node to obtain a label value allocated by the PQ node to the PQ node (S21), and for the PQ node, the PQ node receives the label request message, so that each label request message needs to be distinguished by an identification bit, and the correct label value can be fed back to the source node. If the label request message received by the PQ node does not carry the identification bit or the carried identification bit is not a preset value, the PQ node feeds back the label value distributed to the PQ node to the source node; and if the label request message received by the PQ node carries an identification bit or the carried identification bit is a preset value, the PQ node feeds back the label value allocated to the next hop node to the source node.

And S25, receiving the label value of the next hop node fed back by the PQ node.

Please refer to S15 in fig. 3 for details, which are not described herein.

And S26, pushing the received label value into the next layer of the label value allocated by the PQ node to update the initial backup label path.

As described in S21, the backup label path is stored in the form of a stack, and thus, pushing the received label value to the label stack by the source node may include the following steps:

and S261, determining the position of the label value allocated to the PQ node in the label stack.

The source node may traverse the entire label stack to determine the location of the label value that the PQ node assigns to itself.

S262, insert the received tag value into the layer next to the determined position.

After the position is determined, the source node sequentially shifts down all the tag values after the determined position by one storage interval so as to insert the received tag values.

In the update method for the backup label path provided in this embodiment, the identification bit is sent to the PQ node, so that the PQ node can distinguish the purpose that the local node (source node) sends the address information of the next hop node to the PQ node (source node) based on the identification bit, the accuracy of the label value fed back by the PQ node is improved, and the reliability of the backup path is further ensured.

In this embodiment, an updating method of a backup label path is provided, which can be used in the above-mentioned network device, such as a router, a switch, and the like, and fig. 5 is a flowchart of the updating method of the backup label path according to the embodiment of the present disclosure, and as shown in fig. 5, the flowchart includes the following steps:

and S31, receiving the address information sent by the source node.

Wherein the address information is address information of a local next hop node, and the local is a PQ node corresponding to the source node and the next hop node; the address information also carries an identification bit, and the identification bit is used for requesting local allocation of a label value for the next hop node.

The address information received by the PQ node carries an identification bit, and the PQ node can determine the purpose of the received address information based on the identification bit, that is, the PQ node can allocate a label value to the local next hop node, which corresponds to step S13 in the embodiment shown in fig. 3.

S32, assigning a label value to the next hop node based on the address information of the next hop node.

And after receiving the address information of the next hop node, the PQ node allocates a label value for the next hop node.

S33, sending the label value to the source node.

This step corresponds to S14 in the embodiment shown in fig. 3.

In the method for updating a backup label path provided in this embodiment, a local node receives address information of a local next hop node sent by a source node, and the address information carries an identification bit, and the local node confirms that a label value needs to be allocated to the next hop node at this time by using the identification bit, and then a corresponding ground source node receives the label value locally allocated to its next hop node, so that two layers of labels exist in the updated backup label path corresponding to a PQ node, the first layer of labels is the label value allocated to the PQ node itself, and the second layer of labels is the label value allocated to the PQ node to its next hop node.

In this embodiment, an updating method of a backup label path is provided, which can be used in the above-mentioned network device, such as a router, a switch, and the like, fig. 6 is a flowchart of the updating method of the backup label path according to the embodiment of the present disclosure, and as shown in fig. 6, the flowchart includes the following steps:

and S41, receiving the label request message sent by the source node.

Wherein, the tag request message carries local address information. Corresponding to the initial backup path construction of the source node, the source node needs to determine the PQ node and send a label request message to the PQ node, that is, the PQ node receives the label request message sent by the source node, and the message carries the address of the PQ node.

S42, assigning a tag value to the local based on the tag request message.

After receiving a label request message carrying an address of the PQ node, the PQ node allocates a label value to the PQ node; i.e. locally assigned a tag value.

And S43, sending the local assigned label value to the source node.

The PQ node replies the locally allocated label value to the source node, and the source node requests to allocate the label value to the PQ node to form a backup label path before message forwarding, so that the backup path can be updated based on the backup label path in the following process, and the problem that the backup path is unavailable due to the fact that the backup label path cannot be acquired under the condition of certain scene conflicts can be avoided.

And S44, receiving the address information sent by the source node.

Please refer to S31 in fig. 5, which is not repeated herein.

S45, assigning a label value to the next hop node based on the address information of the next hop node.

The PQ node receives the address information of the next hop node and also receives an identification bit corresponding to the address of the next hop node. After obtaining the identification bit, the PQ node judges whether to allocate a label value to the next hop node or not by using the identification bit.

S46, sending the label value to the source node.

Corresponding to S25 in the embodiment shown in fig. 4.

In the update method for the backup label path provided in this embodiment, the local node (PQ node) receives the identification bit, and can distinguish the purpose of the address information received by the local node based on the identification bit, so as to improve the accuracy of the label value fed back by the local node, and further ensure the reliability of the backup path.

The embodiment of the present disclosure further provides an update method of a backup path, which may be applied between network devices, as shown in fig. 7, where the method includes:

s51, the source node obtains an initial backup label path.

Please refer to S11 in fig. 3 for details, which are not described herein.

S52, the source node determines whether the network path corresponding to the locally connected node has changed.

When the network path corresponding to the locally connected node changes, S53 is performed; otherwise, S52 is executed.

Please refer to S12 in fig. 3 for details, which are not described herein.

S53, the source node transmits address information of a next hop node of the PQ node to the PQ node.

Please refer to S13 in fig. 3 for details, which are not described herein.

S54, the PQ node assigns a label value to the next hop node based on the address of the next hop node.

Please refer to S32 in the embodiment shown in fig. 5, which is not described herein again.

S55, the PQ node sends a label value to the source node.

Please refer to S33 in fig. 5, which is not repeated herein.

And S56, the source node pushes the received label value into the next layer of the label value allocated by the PQ node for the source node, and updates the initial backup label path.

Please refer to S15 in fig. 3 for details, which are not described herein.

The present embodiment further provides an update method of a backup path, as shown in fig. 8, including:

s601, the source node acquires a network path corresponding to the locally connected node.

Please refer to S211 in fig. 4 for details, which are not described herein.

S602, the source node determines a PQ node based on the network path.

Please refer to S212 of the embodiment shown in fig. 4 for details, which are not described herein again.

S603, the PQ node receives the label request message sent by the source node.

Please refer to S41 in fig. 6 for details, which are not described herein.

S604, the PQ node assigns a tag value to the local based on the tag request message.

Please refer to S42 in fig. 6 for details, which are not described herein.

S605, the PQ node sends the locally assigned tag value to the source node.

Please refer to S43 in fig. 6 for details, which are not described herein.

S606, the source node judges whether the network path corresponding to the node connected with the local node changes.

When the network path corresponding to the locally connected node changes, S607 is performed; otherwise, S606 is performed.

Please refer to S22 in fig. 4 for details, which are not described herein.

S607, the source node transmits address information of a next hop node of the PQ node to the PQ node.

Please refer to S23 in fig. 4 for details, which are not described herein.

S608, the PQ node assigns a label value to the next hop node based on the address of the next hop node.

Please refer to S45 in fig. 6 for details, which are not described herein.

S609, the PQ node sends the tag value to the source node.

Please refer to S46 in fig. 6 for details, which are not described herein.

S610, the source node pushes the received label value into the next layer of the label value distributed by the PQ node for the source node, and updates the initial backup label path.

Please refer to S26 in fig. 4 for details, which are not described herein.

As a specific application example of the present embodiment, please refer to fig. 2, and the method for updating the backup label path of the present embodiment is described in detail as follows:

when the topology changes so that the PQ calculation changes and the FRR does not exist, the LDP session established with the PQ does not time out, and when there is a remote session that does not time out but will time out later due to the RLFA calculation becoming a failure, a label request message of LDP is locally initiated to the PQ node, which indicates a change in the topology of the PQ node but a request message that requires maintenance of a backup route. The FEC included in the request message is a set of addresses whose backup routes cannot be calculated due to the RLFA topology change, for example, the FEC sent to 1 by 4 in the figure is 3.3.3.3/32, and in this request message (the request message may but is not limited to use a label request message), at the same time, an identification bit may be added to the reserved bit of the LDP message, after receiving this message, the peer device 1 will reply to 4 with a locally 3.3.3.3/32 and an assigned label value (the label reply may but is not limited to use a label mapping message), after receiving 4, store this received label, and push the label value to the next layer of the LDP TUNNEL when the previous RLFA topology change is formed.

When IGP synchronization triggering, RLFA calculation failure and LDP conversation are not timed out, the device No. 4 does not delete the previously formed initial backup label path of RLFA, and pushes the received label value to the next layer of LDP TUNNEL of the initial backup label path to update the initial backup label path.

If the original backup label path of the newly generated RLFA exists, the L4 link fails, and the backup label path obtained in the above embodiment is used, so that the backup label path has two labels at the position corresponding to the PQ node, where the first label is the LDP TUNNEL of the original RLFA, that is, the label value allocated by the PQ node to itself, and the second label is the label value allocated by the PQ node to the next node. The two layers of labels can ensure that the backup label path is available when the network path fluctuates.

In accordance with an embodiment of the present disclosure, there is provided a message forwarding method embodiment, it should be noted that the steps shown in the flowchart of the drawings may be executed in a computer system such as a set of computer executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in an order different from that here.

In this embodiment, a message forwarding method is provided, which may be used in the above-mentioned network device, such as a router, a switch, and the like, fig. 9 is a flowchart of an updating method of a backup label path according to an embodiment of the present disclosure, and as shown in fig. 9, the flowchart includes the following steps:

and S71, acquiring the message to be forwarded and the backup label path.

The backup label path is formed according to the update method of the backup label path described in any one of the embodiments of fig. 3 to 4.

And S72, packaging the message to be forwarded based on the backup label path to obtain the multi-protocol label switching message.

After obtaining the message to be forwarded and the backup label path, the source node attaches the backup label path to the message header of the message to be forwarded to form a multi-protocol label switching message.

And S73, forwarding the multi-protocol label switching message to the PQ node.

The source node can forward the packet to be forwarded to the PQ node based on the label value distributed by the PQ node in the backup label path.

In the packet forwarding method provided in this embodiment, two layers of labels may exist in the backup label path corresponding to the PQ node, where the first layer of label is a label value allocated by the PQ node to the PQ node, and the second layer of label value allocated by the PQ node to the next hop node, and when the network path changes (that is, an IP routing table does not exist) due to the two layers of label values, the packet can be forwarded from the PQ node to the next hop node by label forwarding, so that a large amount of flow break is prevented.

The embodiment of the present disclosure further provides a message forwarding method, which may be used in the foregoing network device, such as a router, a switch, and the like, fig. 10 is a flowchart of an updating method of a backup label path according to the embodiment of the present disclosure, and as shown in fig. 10, the flowchart includes the following steps:

and S81, receiving the multi-protocol label switching message.

The multi-protocol label switching message carries a backup label path, and the backup label path is formed according to the update method of the backup label path described in any one of the embodiments of fig. 5 or fig. 6.

And the PQ node receives a multi-protocol label switching message sent by the source node.

S82, the multi-protocol label switching message is analyzed to obtain a backup label path.

The PQ node analyzes the received multi-protocol label switching message, and can obtain a backup label path attached to the message header of the message to be forwarded.

And S83, forwarding the multi-protocol label switching message based on the backup label path.

And the PQ node forwards the multi-protocol exchange message based on the obtained backup label path.

This embodiment also provides a message forwarding method, which can be used in the above network devices, such as a router and a switch, and fig. 11 is a flowchart of an updating method of a backup label path according to an embodiment of the present disclosure, and as shown in fig. 11, the flow includes the following steps:

s91, the source node obtains the message to be forwarded and the backup label path; the backup label path is formed according to the update method of the backup label path described in any one of the embodiments of fig. 3 to 4. Please refer to S71 in fig. 9 for details, which are not described herein.

And S92, packaging the message to be forwarded based on the backup label path to obtain the multi-protocol label switching message. Please refer to S72 in fig. 9 for details, which are not described herein.

And S93, forwarding the multi-protocol label switching message to the PQ node. Please refer to S73 in fig. 9 for details, which are not described herein.

S94, the multi-protocol label switching message is analyzed to obtain a backup label path. Please refer to S82 in fig. 10, which is not described herein.

And S95, forwarding the multi-protocol label switching message based on the backup label path. Please refer to S83 in fig. 10, which is not described herein.

As a specific implementation manner of this embodiment, please refer to fig. 2, the process of forwarding a packet is described in detail as follows:

the packet to be forwarded carries two labels, the first label is the LDP TUNNEL of the original RLFA (i.e. PQ is the label value allocated to PQ itself), and the packet is sent to the PQ node, i.e. the device No. 1 in the above figure; after popping up the label, the device No. 1 finds that a layer of label is also arranged, the label is locally distributed to the device No. 3, and then the label is still moved for forwarding, and the message is forwarded to the device No. 3. This successfully protects the address from device number 4 to device number 3.

In addition, the protection can be selected to exist for a long time, and the PQ is recalculated successfully only after the IGP synchronization is finished, so that the previous main/standby state can be recovered; it can also be timed, such as the arrival of LDP remote session timeout, and the backup label path is automatically deleted.

In this embodiment, a device for updating a backup path is further provided, where the device is used to implement the foregoing embodiments and preferred embodiments, and details are not repeated for what has been described. As used below, the term "module" may be a combination of software and/or hardware that implements a predetermined function. Although the means described in the embodiments below are preferably implemented in software, an implementation in hardware, or a combination of software and hardware is also possible and contemplated.

The present embodiment provides an update apparatus for a backup path, as shown in fig. 12, including:

a first obtaining module 101, configured to obtain an initial backup label path, where the initial backup label path includes a label value allocated by a PQ node;

a first sending module 102, configured to send, to the PQ node, address information of a next hop node of the PQ node when a network path corresponding to a locally connected node changes;

a first receiving module 103, configured to receive a tag value of the next hop node fed back by the PQ node; wherein the label value of the next hop node is generated by the PQ node based on address information of the next hop node;

an updating module 104, configured to push the received tag value into a layer below a tag value allocated by the PQ node for the PQ node, and update the initial backup tag path.

The update apparatus for a backup path according to this embodiment requests a PQ node to send a label value allocated to a next hop node when sensing that a network path corresponding to a node connected locally changes, so that two layers of labels may exist in the updated backup label path corresponding to the PQ node, where the first layer of label is a label value allocated by the PQ node to itself, and the second layer of label value is a label value allocated by the PQ node to its next hop node.

In some optional implementations of this embodiment, the network path change corresponding to the locally connected node is to trigger IGP synchronization and the LDP session is not timed out.

As an optional implementation manner of this embodiment, the initial backup label path is stored by using a label stack; as shown in fig. 13, the update module 104 includes:

a position determining unit 1041, configured to determine, in the label stack, a position of a label value that is allocated to the PQ node by the PQ node;

an inserting unit 1042 configured to insert the received tag value into a layer next to the determined position.

Further optionally, as shown in fig. 13, the updating apparatus for the backup path further includes:

an identification bit sending module 105, configured to send an identification bit to the PQ node; and the identification bit corresponds to the address information of the next hop node.

Optionally, as shown in fig. 13, the first obtaining module 101 includes:

an obtaining unit 1011 is configured to obtain a network path corresponding to a locally connected node.

A network path determining unit 1012, configured to determine the PQ node based on the network path.

A label requesting unit 1013, configured to send a label request message to the PQ node to obtain the backup label path.

The present embodiment further provides an updating apparatus for a backup path, as shown in fig. 14, including:

a second receiving module 121, configured to receive address information sent by the source node; the address information is address information of a local next hop node, and the local node is a PQ node corresponding to the source node and the next hop node; the address information also comprises an identification bit, and the identification bit is used for requesting local allocation of a label value for the next hop node; .

A tag value allocating module 122, configured to allocate a tag value to the next-hop node based on the address information of the next-hop node.

A second sending module 123, configured to send the tag value to the source node.

The update apparatus for a backup path provided in this embodiment locally receives address information of a local next hop node sent by a source node, and carries an identification bit in the address information, and locally determines that a label value needs to be allocated to the next hop node at this time by using the identification bit, so that a corresponding ground source node receives the label value locally allocated to its next hop node, so that two layers of labels may exist in the updated backup label path corresponding to a PQ node, where the first layer of labels is the label value allocated by the PQ node for itself, and the second layer of labels is the label value allocated by the PQ node for its next hop node.

As an optional implementation manner of this embodiment, as shown in fig. 15, the backup label path updating apparatus further includes:

a third receiving module 124, configured to receive the tag request message sent by the source node.

A local tag value assignment module 125, configured to assign a tag value to a local based on the tag request message.

A third sending module 126, configured to send the locally assigned tag value to the source node.

In this embodiment, a message forwarding apparatus is further provided, and the apparatus is used to implement the foregoing embodiments and preferred embodiments, and details of which have been already described are omitted. As used below, the term "module" may be a combination of software and/or hardware that implements a predetermined function. Although the means described in the embodiments below are preferably implemented in software, an implementation in hardware, or a combination of software and hardware is also possible and contemplated.

This embodiment provides a packet forwarding apparatus, as shown in fig. 16, including:

a second obtaining module 141, configured to obtain a packet to be forwarded and a backup label path; the backup label path is formed according to the first aspect of the present disclosure, or the update method of the backup label path of any one of the first aspect;

an encapsulating module 142, configured to encapsulate the packet to be forwarded based on the backup label path to obtain a multi-protocol label switching packet;

a first forwarding module 143, configured to forward the multi-protocol label switching packet to the PQ node.

This embodiment provides a packet forwarding apparatus, as shown in fig. 17, including:

a third receiving module 151, configured to obtain a multi-protocol label switching packet; wherein, the multi-protocol label switching message carries a backup label path, and the backup label path is formed according to the second aspect of the disclosure or the updating method of the backup label path in any one of the second aspects;

an analyzing module 152, configured to analyze the multi-protocol label switching packet to obtain the backup label path;

a second forwarding module 153, configured to forward the multi-protocol label switching packet based on the backup label path.

The backup path updating apparatus or the message forwarding apparatus in this embodiment is represented in the form of a functional unit, where the unit refers to an ASIC circuit, a processor and a memory executing one or more software or fixed programs, and/or other devices capable of providing the above functions.

Further functional descriptions of the modules are the same as those of the corresponding embodiments, and are not repeated herein.

The embodiment of the present disclosure further provides a network device, which has an updating apparatus of the backup label path shown in fig. 12 to 13, or has a message forwarding apparatus shown in fig. 16; the embodiment of the present disclosure further provides a network device, which has the updating apparatus for the backup label path shown in fig. 14 to 15, or has the message forwarding apparatus shown in fig. 17. The network devices have similar structures, and a detailed description will be given below by taking, as an example, a network device having an updating apparatus of the backup label path shown in fig. 12 to 13 or a packet forwarding apparatus shown in fig. 16.

Referring to fig. 18, fig. 18 is a schematic structural diagram of a network device according to an alternative embodiment of the present disclosure, and as shown in fig. 18, the network device may include: at least one processor 1601, such as a CPU (Central Processing Unit), at least one communication interface 1603, memory 1604, at least one communication bus 1602. Wherein a communication bus 1602 is used to enable connective communication between these components. The communication interface 1603 may include a Display (Display) and a Keyboard (Keyboard), and the optional communication interface 1603 may further include a standard wired interface and a standard wireless interface. The Memory 1604 may be a high-speed RAM (Random Access Memory) or a non-volatile Memory (non-volatile Memory), such as at least one disk Memory. The memory 1604 may optionally also be at least one storage device located remotely from the processor 1601 as previously described. Wherein the processor 1601 may be in connection with the apparatus described in fig. 12-13, or fig. 16, an application program is stored in the memory 1604, and the processor 1601 calls program code stored in the memory 1604 for performing any of the method steps described above.

The communication bus 1602 may be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus. The communication bus 1602 may be divided into an address bus, a data bus, a control bus, and the like. For ease of illustration, only one thick line is shown in FIG. 18, but this does not mean only one bus or one type of bus.

The memory 1604 may include a volatile memory (RAM), such as a random-access memory (RAM); the memory may also include a non-volatile memory (english: non-volatile memory), such as a flash memory (english: flash memory), a hard disk (english: hard disk drive, abbreviated: HDD) or a solid-state drive (english: SSD); the memory 1604 may also comprise a combination of the above-described types of memory.

The processor 1601 may be a Central Processing Unit (CPU), a Network Processor (NP), or a combination of a CPU and an NP.

The processor 1601 may further include a hardware chip. The hardware chip may be an application-specific integrated circuit (ASIC), a Programmable Logic Device (PLD), or a combination thereof. The PLD may be a Complex Programmable Logic Device (CPLD), a field-programmable gate array (FPGA), a General Array Logic (GAL), or any combination thereof.

Optionally, the memory 1604 is also used to store program instructions. The processor 1601 may call a program instruction to implement an update method of a backup label path as shown in the embodiments of fig. 3 to 4 of the present application, or a message forwarding method as shown in the embodiment of fig. 9.

The embodiment of the present disclosure further provides a non-transitory computer storage medium, where the computer storage medium stores computer-executable instructions, and the computer-executable instructions may execute the update method of the backup label path or the message forwarding method in any of the above method embodiments. The storage medium may be a magnetic Disk, an optical Disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a Flash Memory (Flash Memory), a Hard Disk (Hard Disk Drive, abbreviated as HDD), a Solid State Drive (SSD), or the like; the storage medium may also comprise a combination of memories of the kind described above.

Although the embodiments of the present disclosure have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present disclosure, and such modifications and variations fall within the scope defined by the appended claims.

Claims

1. A method for updating a backup label path is applied to a source node, and the method comprises the following steps:

when IGP synchronization is triggered locally, RLFA calculation fails and an LDP session established with the PQ node is not timed out, initiating a label request message of LDP to the PQ node, and sending address information of a next hop node of the PQ node to the PQ node, wherein the label request message represents a request message that the topology of the PQ node changes but a backup route needs to be maintained, and the address information further comprises an identification bit for requesting the PQ node to allocate a label value to the next hop node;

2. The method of claim 1, wherein the initial backup label path is stored using a label stack; wherein the pushing the received tag value into a layer below a tag value allocated by the PQ node for the PQ node, includes:

inserting the received tag value into a layer next to the determined position.

3. The method of claim 1, wherein obtaining the initial backup label path comprises:

acquiring a network path corresponding to a node connected locally;

determining the PQ node based on the network path;

and sending a label request message to the PQ node to obtain the initial backup label path.

4. A method for updating a backup label path, which is applied to a PQ node, and comprises the following steps:

receiving a label request message and address information of LDP (Low Density parity check) sent by a source node; the label request message and the address message are sent by the source node when IGP synchronization is triggered, RLFA calculation fails, and an LDP session established with the PQ node has not been timed out, the label request message indicates that the PQ node topology changes but a backup route needs to be maintained, the address information is address information of a local next hop node, and the address information further includes an identification bit for requesting the local next hop node to allocate a label value;

and sending the label value to the source node, so that the source node pushes the received label value into a layer below a label value allocated to the source node by the PQ node, and updates an initial backup label path, wherein the initial backup label path comprises the label value allocated to the source node by the PQ node.

5. A message forwarding method is characterized in that, the method comprises the following steps:

acquiring a message to be forwarded and a backup label path; the backup label path is formed according to the updating method of the backup label path of any one of claims 1-3;

and forwarding the multi-protocol label switching message to a PQ node.

6. A message forwarding method is characterized by comprising the following steps:

receiving a multi-protocol label switching message; wherein, the multi-protocol label switching message carries a backup label path, and the backup label path is formed according to the updating method of the backup label path in claim 4;

7. An apparatus for updating a backup label path, applied in a source node, the apparatus comprising:

a first sending module, configured to initiate a label request message of LDP to the PQ node and send address information of a next hop node of the PQ node to the PQ node when IGP synchronization is locally triggered, RLFA calculation fails, and an LDP session established with the PQ node has not timed out yet, where the label request message indicates a request message that the PQ node topology changes but needs to maintain a backup route;

8. An updating apparatus of a backup label path, applied in a PQ node, the apparatus comprising:

the second receiving module is used for receiving a label request message and address information of the LDP sent by the source node; the label request message and the address message are sent by the source node when IGP synchronization is triggered, RLFA calculation fails, and an LDP session established with the PQ node has not timed out, the label request message indicates a request message that the PQ node topology changes but needs to maintain a backup route, and the address information is address information of a local next hop node;

a second sending module, configured to send the tag value to the source node, so that the source node pushes the received tag value into a layer below a tag value allocated to the source node by the PQ node, and updates an initial backup tag path, where the initial backup tag path includes the tag value allocated to the source node by the PQ node.

9. A message forwarding apparatus, comprising:

the second acquisition module is used for acquiring the message to be forwarded and the backup label path; the backup label path is formed according to the updating method of the backup label path of any one of claims 1-3;

10. A message forwarding apparatus, comprising:

a third receiving module, configured to obtain a multi-protocol label switching packet; wherein, the multi-protocol label switching message carries a backup label path, and the backup label path is formed according to the updating method of the backup label path in claim 4;

11. A network device, comprising:

a memory and a processor, the memory and the processor being communicatively connected to each other, the memory having stored therein computer instructions, the processor executing the computer instructions to perform the method of updating the backup label path according to any one of claims 1 to 3 or 4, or to perform the method of forwarding the packet according to claim 5 or 6.

12. A computer-readable storage medium storing computer instructions for causing a computer to execute the method for updating the backup label path according to any one of claims 1 to 3 or 4, or to execute the method for forwarding packets according to claim 5 or 6.