CN118055138A

CN118055138A - Label distribution protocol neighbor keep-alive method, device and equipment

Info

Publication number: CN118055138A
Application number: CN202410288793.5A
Authority: CN
Inventors: 郭威
Original assignee: New H3C Technologies Co Ltd
Current assignee: New H3C Technologies Co Ltd
Filing date: 2024-03-13
Publication date: 2024-05-17

Abstract

The invention provides a label distribution protocol neighbor keep-alive method, device and equipment, which are used for solving the technical problem that the label distribution protocol modifies label switching router identification to greatly influence service. The first LSR sends a first notification message to a neighbor second LSR, notifies the neighbor of LSR ID change, establishes a new LDP session with the second LSR by using the changed new LSR ID and keeps various data information of the old original LDP session unchanged, and only generates a new LSP related to the new LSR ID in the new LDP session; and under the condition that the adjacent information established by the new LDP session is the same as the adjacent information generated by the original LDP session, inheriting forward equivalent FEC upstream and downstream information of the original LDP session in the new LDP session. The invention reduces the influence of modifying LSR ID on service, increases the flexibility of network planning change, and improves the persistence and reliability of user service.

Description

Label distribution protocol neighbor keep-alive method, device and equipment

Technical Field

The present invention relates to the field of communications technologies, and in particular, to a method, an apparatus, and a device for keeping a label distribution protocol neighbor alive.

Background

LDP (Label Distribution Protocol ) is used to dynamically establish LSPs (Label SWITCHED PATH, label switched paths). Through LDP, LSR (Label Switch Router, label switching router) can map network layer IP routing information onto label switched paths in MPLS (Multi-Protocol Label Switching, multiprotocol label switching) networks.

LDP session refers to an LDP protocol connection established over a TCP connection for exchanging FEC-Label Mapping (Forwarding Equivalence Class-Label Mapping) relationships between LSRs, the FEC-Label Mapping indicating the relationship between a particular Forward Equivalence Class (FEC) and a corresponding Label (Label).

LDP peers refer to two LSRs that have LDP sessions between each other and exchange FEC-label mappings through LDP sessions. The LDP ID (LDP IDENTIFIER ) is used to identify the label space of a particular LSR as a six byte value. The format is:

< label switching router identification LSR ID >: < tag space number lable space id >,

Wherein, LSR ID occupies four bytes; the label space sequence number occupies two bytes, and represents the label space of each platform when the value is 0, and represents the label space used by a certain interface when the value is not 0. The LDP protocol runs on an IPv4 network and runs in an IPv6 network using LDP IDs of the same format and requires global uniqueness.

FEC (Forwarding Equivalence Class ) is an important concept in MPLS. MPLS classifies messages with the same characteristics (same destination or same class of service, etc.) into a class called FEC. Messages belonging to the same FEC will get exactly the same processing in the MPLS network. LDP supports partitioning FEC according to destination IP address and PW (Pseudowire ). FEC-Label mapping, also known as FEC-Label Binding (FEC-Label Binding), is the correspondence between labels and FEC on the local LSR device. LDP advertises FEC-Label Mapping to peers via Label Mapping messages.

LDP protocols mainly use four types of messages:

Discovery (Discovery) message: for advertising and maintaining LSRs in the network, such as Hello messages.

Session (Session) message: for setting up, maintaining and terminating sessions between LDP peers, such as Initialization messages used to negotiate session parameters and keep messages used to maintain sessions.

Advertisement (Advertisement) message: for creating, changing and deleting "FEC-Label" mappings, such as Label Mapping messages used to announce Label mappings.

Notification (Notification) message: messages for providing advisory information and error notifications, such as Notification messages.

To ensure reliable sending of LDP messages, session messages, advertisement messages and notification messages of LDP are transmitted using TCP, except that discovery messages are transmitted using UDP.

The LDP working process mainly comprises three stages of peer discovery and maintenance, session establishment and maintenance and LSP establishment. LSR enabled LDP capabilities periodically send Hello messages advertising their presence. Through the Hello message, the LSR may automatically discover its surrounding LSR neighbors and establish a Hello adjacency therewith.

LDP peer discovery mechanisms fall into two categories:

Basic discovery mechanism: for discovering locally directly connected LSR neighbors, i.e. LSRs directly connected through the link layer. In this manner, the LSR periodically sends a Link Hello message of LDP to multicast address 224.0.0.2 (IPv 4 network) or FF 02:0:0:0:0:0:2 (IPv 6 network) so that the LSR directly connected by the Link layer discovers the LSR, and in the network where IPv4 and IPv6 coexist, the LSR may send an IPv4Link Hello message and an IPv6 Link Hello message to the directly connected LSR at the same time, and simultaneously maintain an IPv4Link Hello adjacency and an IPv6 Link Hello adjacency with the adjacency LSR.

Extended discovery mechanism: can be used to discover the far-end non-directly connected LSR neighbors, i.e., LSRs that are not directly connected through the link layer. In this manner, the LSR periodically sends a Targeted Hello message of the LDP to the specified IP address so that the LSR corresponding to the specified IP address discovers the LSR. The extended discovery mechanism is mainly applied to LDP session protection, LDP over MPLS TE, MPLS L2VPN and VPLS.

The LSR may establish two adjacencies of Link Hello and Targeted Hello simultaneously with the directly connected neighbors. The LDP peers maintain Hello adjacencies by periodically sending Hello messages between them. If a new Hello message is not received yet when the Hello hold timer expires, the Hello adjacency is deleted.

After discovering the LSR neighbors by interacting with the Hello messages, the LSR begins to establish a session with the LSR, and after the session is established, the LDP peers maintain the session by sending LDP PDUs (LDP PDUs carry one or more LDP messages). If there is no information to be interacted between LDP peers in the keep alive message sending time interval, the LSR sends keep alive message to LDP peers so as to maintain LDP session. If the keep-alive timer expires, no LDP PDU is received and the LSR will close the TCP connection and end the LDP session. There may be multiple Hello adjacencies over one LDP session. When the last Hello adjacency on the LDP session is deleted, the LSR will send a notification message ending the LDP session.

The LSR divides FEC according to the destination IP address in the IP routing table item, distributes different labels for different FEC, and notifies the FEC-label mapping to the opposite LSR; and the opposite end LSR establishes a label forwarding table item for the label distributed to the FEC according to the received FEC-label mapping. After all LSRs from Ingress to Egress establish the corresponding label forwarding table entry for the FEC, an LSP for forwarding the FEC packet is successfully established.

In an MPLS network, if a label of an LSR in an LSP is modified, according to the definition of the present RFC, all LDP neighbors are rebuilt, including the LSP is also rebuilt, so that the traffic being forwarded is interrupted, and normal operation of the traffic is seriously affected.

Disclosure of Invention

In view of the above, the present invention provides a method, apparatus and device for keeping label distribution protocol neighbor alive, which are used for solving the technical problem that the LDP modifies LSR ID to affect the service too much.

Based on an aspect of the embodiment of the present invention, the present invention provides a label distribution protocol neighbor keep-alive method, which is applied to a first LSR where a label switching router identifier LSR ID is changed, the method includes:

The first LSR sends a first notification message to a neighbor second LSR, wherein the first notification message is used for notifying the neighbor first LSR of LSR ID change, and the first LSR carries a transmission address;

After the first LSR changes the LSR ID and sends a first notification message, a new label distribution protocol LDP session is established with the second LSR by using the changed new LSR ID and each item of data information of the old original LDP session is kept unchanged;

The first LSR and the second LSR only generate a new LSP related to a new LSR ID in the new LDP session;

After the new LSP is generated, the first LSR judges whether the adjacent information established by the new LDP session is the same as the adjacent information generated by the old original LDP session, if so, the forwarding equivalence class FEC upstream and downstream information of the old original LDP session is inherited in the new LDP session;

After judging that the adjacent information is the same and inheriting the FEC upstream and downstream information of the old original LDP session, the first LSR sends the Label Mapping information of the old original LDP session to all the current neighbors, so that the neighbors receiving the Label Mapping information modify the Peer information of the FEC but do not modify the forwarding table.

Further, an error code E flag in the first notification message is set to a flag value of a non-fatal type;

The status Data field in the first notification message is set to a flag value indicating that an LSR ID change has occurred;

the first notification message carries a TLV field for recording the transmission address;

If the changed LSR ID is used as the transmission address, the IP address carried in the transmission address TLV is the changed LSR ID; if the changed LSR ID is not used as the transmission address, the IP address carried in the transmission address TLV is the transmission address used by the original LDP session.

Further, the method further comprises: when the first LSR judges that the adjacent information is different, the first LSR generates new FEC according to the adjacent information of the new LDP session, generates LSP forwarding information corresponding to the adjacent output interface, disconnects the old original LDP session, and deletes the forwarding table corresponding to the old original LDP session.

Based on an aspect of the embodiment of the present invention, the present invention also provides a label distribution protocol neighbor keep-alive method, which is applied to a neighbor second LSR of a first LSR in which a label switching router identifier LSR ID change occurs, the method comprising:

the second LSR receives a first notification message sent by the first LSR, wherein the first notification message is used for notifying neighbor first LSR of LSR ID change, and the first notification message carries a transmission address;

The second LSR establishes a new LDP session with the first LSR based on the changed new LSR ID and keeps various data information of the old original LDP session unchanged;

the second LSR compares the transmission address used by the new LDP session with the transmission address in the first notification message, if the transmission address is the same, the new LDP session is judged to be the session generated by LSR ID change, and the second LSR only generates a new LSP related to the new LSR ID in the new LDP session;

after the new LSP is generated, the second LSR judges whether the adjacent information established by the new LDP session is the same as the adjacent information generated by the old original LDP session, if so, the FEC upstream and downstream information of the old original LDP session is inherited in the new LDP session; if not, generating a new FEC according to the adjacent information of the new LDP session;

After judging that the adjacent information is the same and inheriting the FEC upstream and downstream information of the old original LDP session, the second LSR sends the Label Mapping information of the old original LDP session to all the current neighbors, so that the neighbors receiving the Label Mapping information modify the Peer information of the FEC but do not modify the forwarding table.

Further, the method further comprises: and under the condition that the second LSR judges that the adjacent information is different, the second LSR generates a new FEC according to the adjacent information of the new LDP session, generates LSP forwarding information corresponding to the adjacent output interface, disconnects the old original LDP session, and deletes the forwarding table corresponding to the old original LDP session.

Based on an aspect of the embodiment of the present invention, the present invention further provides a label distribution protocol neighbor keep-alive device, where the device is applied to a first LSR where a label switching router identifier LSR ID is changed, and the device includes:

The change notification module is used for sending a first notification message to the neighbor second LSR, wherein the first notification message is used for notifying the neighbor first LSR of LSR ID change, and the first notification message carries a transmission address;

A first session establishing module, configured to establish a new label distribution protocol LDP session with the second LSR using the changed new LSR ID after changing the LSR ID and sending the first notification message, and keep each item of data information of the old original LDP session unchanged;

a first LSP generating module configured to generate, with a second LSR, only a new LSP related to a new LSR ID in the new LDP session;

The first inheritance module is used for judging whether the adjacent information established by the new LDP session is the same as the adjacent information generated by the old original LDP session after the new LSP is generated, and inheriting forward equivalent FEC upstream and downstream information of the old original LDP session in the new LDP session if the adjacent information is the same;

The first Mapping module is used for sending Label Mapping information of the old original LDP session to all the current neighbors after judging that the adjacent information is the same and inheriting the FEC upstream and downstream information of the old original LDP session, so that the neighbors receiving the Label Mapping information modify the Peer information of the FEC but do not modify the forwarding table item.

Further, the inheritance module is further configured to generate a new FEC according to the adjacency information of the new LDP session, generate LSP forwarding information corresponding to the adjacency outgoing interface, disconnect the old original LDP session, and delete the forwarding table corresponding to the old original LDP session when determining that the adjacency information is different.

Based on an aspect of the embodiment of the present invention, the present invention further provides a label distribution protocol neighbor keep-alive device, where the device is applied to a neighbor second LSR of a first LSR where a label switching router identification LSR ID change occurs, and the device includes:

A change notification receiving module, where the second LSR receives a first notification message sent by the first LSR, where the first notification message is used to notify the neighbor first LSR that an LSR ID change occurs, and the first notification message carries a transport address;

A second session establishing module, configured to establish a new LDP session with the first LSR based on the changed new LSR ID and keep each item of data information of the old original LDP session unchanged;

a second LSP generating module, configured to compare whether a transport address used by a new LDP session and a transport address in the first notification message are the same, and if so, determine that the new LDP session is a session generated by changing an LSR ID, and generate only a new LSP related to the new LSR ID in the new LDP session;

the second inheritance module is used for judging whether the adjacent information established by the new LDP session is the same as the adjacent information generated by the old original LDP session after the new LSP is generated, and inheriting the FEC upstream and downstream information of the old original LDP session in the new LDP session if the adjacent information is the same; if not, generating a new FEC according to the adjacent information of the new LDP session;

And the second Mapping module is used for transmitting Label Mapping information of the old original LDP session to all the current neighbors after judging that the adjacent information is the same and inheriting the FEC upstream and downstream information of the old original LDP session, so that the neighbors receiving the Label Mapping information modify the Peer information of the FEC but do not modify the forwarding table item.

When existing service exists, LSR ID of modifying LDP has great influence, LDP is generally used for important public bearing network in network, current network deployment update iteration speed is high, planning is likely to be changed, or new topology is likely to be accessed, negative influence of modifying LSR ID cannot be estimated

The first LSR sends a first notification message to a neighbor second LSR, notifies the neighbor of LSR ID change, establishes a new LDP session with the second LSR by using the changed new LSR ID, keeps various data information of the old original LDP session unchanged, and only generates a new LSP related to the new LSR ID in the new LDP session; and under the condition that the adjacent information established by the new LDP session is the same as the adjacent information generated by the old original LDP session, inheriting forward equivalent FEC upstream and downstream information of the old original LDP session in the new LDP session. LDP is generally used for important public bearing network in network, the current network deployment update iteration speed is high, the planning is likely to be changed, or new topology is likely to be accessed, the influence of modifying LSR ID on user service is very large, the influence of modifying LSR ID on service is reduced, the flexibility of network planning change is increased, and the persistence and reliability of user service are improved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following description will briefly describe the drawings required to be used in the embodiments of the present invention or the description in the prior art, and it is obvious that the drawings in the following description are only some embodiments described in the present invention, and other drawings may be obtained according to these drawings of the embodiments of the present invention for a person having ordinary skill in the art.

Fig. 1 is a schematic diagram of an MPLS network according to an embodiment of the present invention;

FIG. 2 is a flow chart of an embodiment of the present invention of an LDP neighbor keep-alive method;

fig. 3 is a schematic structural diagram of an electronic device for implementing the LDP neighbor keep-alive method provided by an embodiment of the present invention.

Detailed Description

The terminology used in the embodiments of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of embodiments of the invention. As used in this embodiment of the invention, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. Although embodiments of the present invention may be described in terms of first, second, and third aspects, such descriptions are merely provided to distinguish one from another information, entity, or step, and not to describe a particular sequence or order. For example, the first information may also be referred to as second information, and similarly, the second information may also be referred to as first information, without departing from the scope of embodiments of the present invention. For another example, in some scenarios, the first information may refer to one information, or may refer to multiple information in the same class. Furthermore, the word "if" as used may be interpreted as "at … …" or "at … …" or "in response to a determination. The "and/or" in the present invention is merely an association relationship describing the association object, and indicates that three relationships may exist, for example, a and/or B may indicate: there are three cases, a alone, a and B together, and B alone, wherein a, B may be singular or plural. Also, in the description of the present invention, unless otherwise indicated, "a plurality" means two or more than two. "at least one of" or the like means any combination of these items, including any combination of single item(s) or plural items(s). For example, at least one (one) of a, b, or c may represent: a, b, c, a-b, a-c, b-c, or a-b-c, wherein a, b, c may be single or plural.

Fig. 1 is a schematic diagram of an MPLS network according to an embodiment of the present invention. In the MPLS network, LDP neighbors are established in pairs between routing devices, if RouterB needs to longitudinally expand a service, connect other networking topologies, and if an LSR ID in LDP IDs is 2.2.2.9, and if a new topology also has an ID of 2.2.2.9 or other IDs are used in service modification needs, modifying the LDP ID according to RFC standard 5036 will send a deadly Notification message, resulting in that all LDP sessions associated with the LDP session are DOWN, reestablishing neighbors, regenerating LSPs, and if password authentication configuration exists, the configuration needs to be re-issued for neighbor verification, which causes a huge impact on services.

The format of the LDP ID in RFC is defined as:

< label switching router identification LSR ID >: < tag space number lable space id >.

Wherein, LSR ID occupies four bytes; the label space sequence number occupies two bytes, and represents the label space of each platform when the value is 0, and represents the label space used by a certain interface when the value is not 0.

Because the label space is basically 0 in the label space industry at present, modifying the LSR ID is equivalent to modifying the LDP ID. The modification of the LDP identifier in the invention is mainly aimed at the modification of LSR ID. Currently, there are various ways of modifying LSR ID, disconnecting an existing LDP session, such as sending a Notification message to close a shutdown, disconnecting a TCP connection (possibly using the address of LSR ID to establish a TCP connection), etc., and then restarting to establish LDP neighbors and sending LSPs with a new LSR ID.

If, as in the example of fig. 1, the hosts within the segments of 11.1.1.0/24 and 21.1.1.0/24 are forwarding user traffic using LDP-formed LSPs, all neighbors, including LSPs, will be re-established as Router B modifies the key identifier LSR ID, so that the forwarding traffic will be interrupted, resulting in interruption of all traffic going through the original LSPs, the time of link restoration being affected by the device set-up speed, few seconds of traffic interruption, and more about 1 minute of interruption.

Based on the above analysis, the LSR ID of the LDP is modified to have a huge impact, and LDP is generally used in a public bearer network which is important in the network, and as the iteration speed of network deployment and update increases, it may become more frequent to change the planning or access to a new topology, and the modification of the LSR ID causes the service to be unavailable and has a greater negative impact.

In order to solve the technical problem that modifying an LSR ID (equivalent to modifying an LDP ID) causes service interruption or excessively long interruption time, the present invention provides an LDP neighbor keep-alive scheme, and the technical scheme provided in the present invention is described in detail below with reference to the drawings and the embodiments, it should be noted that the steps shown in the flowchart of the drawings may be performed 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 performed in an order different from that shown or described herein.

Fig. 2 is a flow chart of an LDP neighbor keep-alive method according to an embodiment of the invention. The method comprises the following steps:

Step 201, a first LSR with LSR ID change sends a first notification message to a neighbor second LSR, wherein the first notification message is used for notifying the neighbor first LSR of LSR ID change, and the first LSR carries a transmission address; the second label LSR receives a first notification message sent by the first LSR.

An Error Code (E mark) mark is defined in the Notification message of the original LDP protocol and is used for indicating the Error type, and the Error type and the corresponding Error condition can be identified by the LDP neighbor device through the E mark, so that proper processing and response are performed. When the E flag is set to 0, it is used to indicate that the notification message is a general notification or a non-fatal type notification such as a state change notification, session maintenance, etc. When the value of the E flag is greater than 1, the error generated is represented as a more serious or fatal error, such as a label distribution failure, an LDP session error, a connection abnormality, and the like.

In an embodiment of the present invention, the first Notification message still adopts the Notification message format of LDP protocol, but is modified by setting E flag to 0, setting status Data field to a new flag value (e.g. 0X 00000078) to indicate that the LSR ID change (LSR CHANGE) has occurred, and carrying a type length value TLV field for recording transport address (Tranport Address) in the Notification message.

The filling rule of the transmission address TLV field in an embodiment of the invention is as follows:

The IP address in the TLV is filled with the IP address for establishing TCP connection by the LDP neighbor after the LSR ID is changed;

if the LSR ID is changed, the changed LSR ID is used as a transmission address, and the IP address carried in the transmission address TLV is the changed LSR ID; if the changed LSR ID is not used as the transmission address, the IP address carried in the transmission address TLV is the transmission address used by the original LDP session. Whether to use the LSR ID as the transport address is determined by the device configuration of the first LSR.

After receiving the first notification message, the LDP session neighbor of the first LSR will save the contents of the transport address TLV field, but will not disconnect the existing neighbor immediately (without disconnecting the TCP, sending the deadly notification message), nor change the LSP forwarding table entry.

Step 202, after the first LSR changes the LSR ID and sends the first notification message, a new LDP session is established with the second LSR by using the changed new LSR ID and each item of data information of the old original LDP session is kept unchanged; the second LSR establishes a new LDP session with the first LSR based on the changed new LSR ID and keeps various data information of the old original LDP session unchanged;

If the transmission address in the first notification message is the changed new LSR ID and can establish the LDP session, or if the transmission address in the first notification message is the transmission address of the old LDP session, the new LSR ID and the LDP neighbor are used to establish the new LDP session without affecting the original old LDP session, and each item of data information of the old LDP session is kept unchanged.

In an embodiment of the present invention, if a new LDP session cannot be established by using a new LSR ID within a specified time, an old LDP session can be selectively disconnected over time, or maintained for a long time, and if disconnected, the service is interrupted according to the original flow.

Step 203, after the first LSR establishes a new LDP session connection with the second LSR using the new LSR ID, the second LSR compares whether the transport address used by the new LDP session is the same as the transport address in the first notification message, if so, determines that the new LDP session is a session generated by the LSR ID change, and executes step 204;

In an embodiment of the present invention, if the session neighbor peer, for example, the second LSR, finds that the transport address used by the new LDP session and the transport address in the first notification message are different after the comparison, it is determined that the new LDP session is not a new session generated by the LSR ID change, and in this case, the new LDP session is processed according to the original LDP protocol specification, which is not described herein.

Step 204, the first LSR and the second LSR only generate a new LSP related to the new LSR ID in the new LDP session, and then execute step 205; .

There may be multiple Hello adjacencies in one LDP session, there may be multiple LSP paths in the original session, and the change of LSR ID of the first LSR may affect only part of LSPs in the original session, so this step generates new LSPs related to the changed new LSR ID only in the new LDP session, and does not generate other LSPs not related to the changed new LSR ID, which is to avoid affecting forwarding of the irrelevant LSP paths in the original session.

Step 205, after the new LSP is generated, all the LDP neighbors (including the first LSR and the second LSR) related to the new LSP will judge whether the adjacency information established by the new LDP session is the same as the adjacency information generated by the old original LDP session, if so, the FEC upstream and downstream information of the old original LDP session is inherited in the new LDP session;

the adjacency information refers to interface information sent by a keep-alive hello message for generating the LDP session.

In an embodiment of the present invention, if all LDP neighbors related to the new LSP judge that the adjacency information is different, after judging that the LSR ID for establishing the new LDP session is the new LSR ID in the first notification message, the corresponding node generates a new FEC according to the adjacency information of the new LDP session, generates LSP forwarding information corresponding to the adjacency outgoing interface, disconnects the old original LDP session, and deletes the forwarding table corresponding to the old original LDP session, so that the traffic can be rapidly switched to the new forwarding information.

Step 206, after all the LDP neighbors related to the new LSP determine that the adjacency information established by the new LDP session is the same as the adjacency information generated by the old original LDP session, and inherit the upstream and downstream information of FEC of the old original LDP session, the Label Mapping message of the old original LDP session is sent to all the current neighbors, so that after judging that the LSR ID in the Label Mapping message is the LSR ID in the first notification message, the neighbors receiving the Label Mapping message only modify the Peer information of FEC, and do not modify the forwarding table entry, and maintain the forwarding of the original table entry.

After the above steps are completed, the session relation related to the old LSR ID can be disconnected in the original LDP session, and each LSR node disconnects the forwarding table LSP related to the old original LDP neighbor relation without deleting the original LDP neighbor relation after judging the new LDP session established by the LSR ID change, and only disconnects the session.

Taking the networking in fig. 1 as an example to describe the implementation of the LDP neighbor keep-alive method of the present invention, assuming that the traffic is being forwarded between devices with IP addresses of 11.1.1.1 and 21.1.1.1, the LSR ID in the first LSR, i.e., router B, is changed from 2.2.2.9 to 22.2.2.9 (the address may correspond to another loopback interface), and the changed address 22.2.2.9 actually exists and the opposite end is reachable, the first LSR sends a first notification message to Router a and Router C, where the transport address in the transport address TLV carried in the first notification message is 22.2.2.9. After Router a and Router C receive the first notification message, discover that the transport address 22.2.2.9 in the transport address TLV in the message is a new transport address, attempt to establish a new TCP connection using the address, establish a new LDP session and maintain the old, original LDP session information established at 2.2.2.9. When Router a and Router C find that the transport address of the new LDP session is the same as the IP address in the transport address TLV in the first notification message during the process of establishing the new LDP session, the process of the invention LSR CHANGE is enabled to generate a new LSP related to the new LSR ID, that is, 22.2.2.9, and other LSPs are not generated, so that many other LSPs may exist in the original LDP session according to the protocol implementation. Taking Router a as an example, router a and Router B establish a new LDP session, the LSR ID of Router a is unchanged, a new LSP related to the new LSR ID, that is 22.2.2.9, is established in the new LDP session, the LSP is generated by FEC, because the physical interface information and configuration in the network are unchanged, only the used LSR ID is modified, so that the new session is identical to the adjacency information of the old session, router a inherits the FEC information of 11.1.1.1 in the old original LDP session of 2.2.2.9 into the new LDP session information of 22.2.2.9, and modifies peer information of the FEC information into 22.2.2.9, otherwise, the peer information does not affect traffic forwarding, after all LSP information inherits, the neighbor session related to 2.2.2.9 is disconnected, meanwhile, because the session is the original session related to LSR CHANGE flow inherits the front and back, the LSP forwarding information is not changed, and the user traffic is not interrupted.

Based on the above embodiments, the technical solution of the present invention can minimize the influence of the LDP modifying the LSR ID on the service to the maximum extent, increase the flexibility of network planning variation, and protect the user service from interruption.

Fig. 3 is a schematic structural diagram of an electronic device for implementing the LDP neighbor keep-alive method according to an embodiment of the present invention, where the device 300 includes: a processor 310 such as a Central Processing Unit (CPU), a communication bus 320, a communication interface 340, and a memory 330. Wherein the processor 310 and the memory 330 may communicate with each other via a communication bus 320. Memory 330 has stored therein a computer program which, when executed by processor 310, performs the functions of one or more steps of the LDP neighbor keep-alive method provided by the present invention.

Memory refers to a device for storing computer programs and/or data based on some storage medium, which may be a Volatile Memory (VM) or a Non-Volatile Memory (NVM). The memory is an internal memory for directly exchanging data with the processor, and can read and write data at any time, and has high speed, and is used as a storage medium for temporary data of an operating system and other running programs. The memory may be synchronous dynamic random access memory (Synchronous Dynamic Random Access Memory, SDRAM), dynamic random access memory (Dynamic Random Access Memory, DRAM), etc. The nonvolatile memory is a memory using a persistent storage medium, and has a large capacity and can store data permanently, and may be a storage class memory (Storage Class Memory, SCM), a Solid state disk (Solid STATE DISK, SSD), a NAND flash memory, a magnetic disk, or the like. SCM is a common name for new storage medium between memory and flash memory, and is a composite storage technology combining persistent storage characteristic and memory characteristic, and has access speed slower than that of DRAM and SSD hard disk.

The processor may be a general-purpose processor including a central processing unit (Central Processing Unit, CPU), a network processor (Network Processor, NP), etc.; but may also be a digital signal processor (DIGITAL SIGNAL Processing, DSP), application SPECIFIC INTEGRATED Circuit (ASIC), field-Programmable gate array (Field-Programmable GATE ARRAY, FPGA) or other Programmable logic device, discrete gate or transistor logic device, discrete hardware components.

It should be appreciated that embodiments of the invention may be implemented or realized by computer hardware, a combination of hardware and software, or by computer instructions stored in non-transitory (or referred to as non-persistent) memory. The method may be implemented in a computer program using standard programming techniques, including a non-transitory storage medium configured with a computer program, where the storage medium so configured causes a computer to operate in a specific and predefined manner. Each program may be implemented in a high level procedural or object oriented programming language to communicate with a computer system. However, the program(s) can be implemented in assembly or machine language, if desired. In any case, the language may be a compiled or interpreted language. Furthermore, the program can be run on a programmed application specific integrated circuit for this purpose. Furthermore, the operations of the processes described in the present invention may be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The processes (or variations and/or combinations thereof) described herein may be performed under control of one or more computer systems configured with executable instructions, and may be implemented as code (e.g., executable instructions, one or more computer programs, or one or more applications), by hardware, or combinations thereof, collectively executing on one or more processors. The computer program includes a plurality of instructions executable by one or more processors.

Further, the method may be implemented in any type of computing platform operatively connected to a suitable computing platform, including, but not limited to, a personal computer, mini-computer, mainframe, workstation, network or distributed computing environment, separate or integrated computer platform, or in communication with a charged particle tool or other imaging device, and so forth. Aspects of the invention may be implemented in machine-readable code stored on a non-transitory storage medium or device, whether removable or integrated into a computing platform, such as a hard disk, optical read and/or write storage medium, RAM, ROM, etc., such that it is readable by a programmable computer, which when read by a computer, is operable to configure and operate the computer to perform the processes described herein. Further, the machine readable code, or portions thereof, may be transmitted over a wired or wireless network. When such media includes instructions or programs that, in conjunction with a microprocessor or other data processor, implement the steps described above, the invention described herein includes these and other different types of non-transitory computer-readable storage media. The invention also includes the computer itself when programmed according to the methods and techniques of the present invention.

The foregoing is merely exemplary of the present invention and is not intended to limit the present invention. Various modifications and variations of the present invention will be apparent to those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A label distribution protocol neighbor keep-alive method, applied to a first LSR that has undergone a label switching router identification LSRID change, the method comprising:

The first LSR sends a first notification message to a neighbor second LSR, wherein the first notification message is used for notifying the neighbor first LSR of LSRID changes, and the first LSR carries a transmission address;

After LSRID is changed and a first notification message is sent, the first LSR establishes a new Label Distribution Protocol (LDP) session with the second LSR by using the new LSRID after the change and keeps all data information of the old original LDP session unchanged;

After judging that the adjacent information is the same and inheriting the FEC upstream and downstream information of the old original LDP session, the first LSR sends a label mapping LabelMapping message of the old original LDP session to all the current neighbors so that the neighbors receiving the LabelMapping message modify the Peer information of the FEC but do not modify the forwarding table entry.

2. The method of claim 1, wherein the step of determining the position of the substrate comprises,

The error code E mark in the first notification message is set to be a mark value of a non-fatal type;

The status Data field in the first notification message is set to a flag value indicating LSRID changes have occurred;

If the changed LSRID is taken as the transmission address, the IP address carried in the transmission address TLV is LSRID after the change; if LSRID is not used as the transport address after the change, the IP address carried in the transport address TLV is the transport address used by the original LDP session.

3. The method according to claim 1, wherein the method further comprises:

When the first LSR judges that the adjacent information is different, the first LSR generates new FEC according to the adjacent information of the new LDP session, generates LSP forwarding information corresponding to the adjacent output interface, disconnects the old original LDP session, and deletes the forwarding table corresponding to the old original LDP session.

4. A label distribution protocol neighbor keep-alive method, applied to a neighbor second LSR of a first LSR that has undergone a label switching router identification LSRID change, the method comprising:

the second LSR receives a first notification message sent by the first LSR, wherein the first notification message is used for notifying a neighbor first LSR of LSRID changes, and the first LSR carries a transmission address;

The second LSR compares the transmission address used by the new LDP session with the transmission address in the first notification message, if the transmission address is the same, the new LDP session is judged to be the session generated by LSRID change, and the second LSR only generates a new LSP related to the new LSRID in the new LDP session;

After judging that the adjacent information is the same and inheriting the FEC upstream and downstream information of the old original LDP session, the second LSR sends the label mapping LabelMapping message of the old original LDP session to all the current neighbors so that the neighbors receiving LabelMapping message modify the Peer information of FEC but not the forwarding table entry.

5. The method of claim 4, wherein the step of determining the position of the first electrode is performed,

6. The method according to claim 4, wherein the method further comprises:

and under the condition that the second LSR judges that the adjacent information is different, the second LSR generates a new FEC according to the adjacent information of the new LDP session, generates LSP forwarding information corresponding to the adjacent output interface, disconnects the old original LDP session, and deletes the forwarding table corresponding to the old original LDP session.

7. A label distribution protocol neighbor keep-alive device for a first LSR that has undergone a label switching router identification LSRID change, the device comprising:

A change notification module, configured to send a first notification message to a neighbor second LSR, where the first notification message is configured to notify the neighbor first LSR that a LSRID change occurs, and the change notification module carries a transport address;

a first session establishing module, configured to establish a new label distribution protocol LDP session with the second LSR using the changed new LSRID after changing the LSR ID and sending the first notification message, and keep each item of data information of the old original LDP session unchanged;

A first LSP generation module configured to generate, with a second LSR, only a new LSP associated with a new LSRID in the new LDP session;

and the first mapping module is used for sending the label mapping LabelMapping message of the old original LDP session to all the current neighbors after judging that the adjacent information is the same and inheriting the FEC upstream and downstream information of the old original LDP session, so that the neighbors receiving the LabelMapping message modify the Peer information of the FEC but do not modify the forwarding table item.

8. The apparatus of claim 7, wherein the device comprises a plurality of sensors,

9. The apparatus of claim 7, wherein the device comprises a plurality of sensors,

And the inheritance module is also used for generating new FEC according to the adjacent information of the new LDP session under the condition that the adjacent information is different, generating LSP forwarding information corresponding to the adjacent output interface, disconnecting the old original LDP session, and deleting the forwarding table corresponding to the old original LDP session.

10. A label distribution protocol neighbor keep-alive apparatus for use with a neighbor second LSR of a first LSR that has undergone a label switching router identification LSRID change, the apparatus comprising:

A change notification receiving module, where the second LSR receives a first notification message sent by the first LSR, where the first notification message is used to notify the neighbor first LSR that a change occurs LSRID, where the change carries a transport address;

A second session establishing module, configured to establish a new LDP session with the first LSR based on the changed new LSRID and keep each item of data information of the old original LDP session unchanged;

A second LSP generating module, configured to compare whether a transport address used by a new LDP session and a transport address in the first notification message are the same, and if so, determine that the new LDP session is a session generated by LSRID changes, and generate only a new LSP related to a new LSRID in the new LDP session;

And the second mapping module is used for sending the label mapping LabelMapping message of the old original LDP session to all the current neighbors after judging that the adjacent information is the same and inheriting the FEC upstream and downstream information of the old original LDP session, so that the neighbors receiving the LabelMapping message modify the Peer information of the FEC but do not modify the forwarding table.

11. An electronic device is characterized by comprising a processor, a communication interface, a storage medium and a communication bus, wherein the processor, the communication interface and the storage medium are communicated with each other through the communication bus;

A storage medium storing a computer program;

a processor for implementing the method of any of claims 1-6 when executing a computer program stored on a storage medium.