CN111740907A

CN111740907A - Message transmission method, device, equipment and machine readable storage medium

Info

Publication number: CN111740907A
Application number: CN202010475412.6A
Authority: CN
Inventors: 汪亮; 吴文; 曹沁
Original assignee: New H3C Security Technologies Co Ltd
Current assignee: New H3C Security Technologies Co Ltd
Priority date: 2020-05-29
Filing date: 2020-05-29
Publication date: 2020-10-02

Abstract

The present disclosure provides a message transmission method, apparatus, device and machine-readable storage medium, the method comprising: receiving a message to be forwarded; updating an identity label field in a message to be forwarded, wherein the identity label field contains information for uniquely identifying local equipment; and forwarding the message to be forwarded so that the opposite-end PE equipment can identify the sending-end PE equipment of the message according to the identity label field. According to the technical scheme, the unique and exclusive equipment label is added in the forwarded message, so that the PE equipment of the opposite end can identify the source of the received message, and the BFD detection function can be realized.

Description

Message transmission method, device, equipment and machine readable storage medium

Technical Field

The present disclosure relates to the field of communications technologies, and in particular, to a method, an apparatus, a device, and a machine-readable storage medium for message transmission.

Background

CE (Customer Edge): a user network side device directly connected to the service provider network.

PE (Provider Edge): a service provider network side device connected to the CE. The PE is mainly responsible for the access of the EVPN VPLS service, and the mapping and forwarding of the message from the user network to the public network tunnel and from the public network tunnel to the user network are completed.

AC (Attachment Circuit, access Circuit): physical or virtual circuits connecting the CE and PE.

LSP (Label Switched Path): a label switched path between two PEs. Two unidirectional LSPs in opposite directions need to be established between PEs.

PW (Pseudowire ): a virtual bidirectional connection between two PEs. The PW is formed from a pair of unidirectional LSPs of opposite direction.

Public network Tunnel (Tunnel): tunnels that traverse the IP or MPLS backbone and are used to carry LSPs. One public network tunnel can carry a plurality of LSPs, and the public network tunnel can be an LSP, a GRE tunnel or an MPLS TE tunnel.

VSI (Virtual Switch Instance): the VSI is a virtual instance on the PE device that provides layer two switching services for one VPLS instance. The VSI can be viewed as a virtual switch on the PE device that has all the functions of a traditional ethernet switch, including source MAC address learning, MAC address aging, flooding, etc. The VPLS realizes the forwarding of the two-layer data message in the VPLS instance through the VSI.

EVPN (Ethernet Virtual Private Network): a two-layer VPN technology, a control plane adopts MP-BGP to announce EVPN routing information, and a data plane adopts VXLAN or MPLS encapsulation mode to forward messages. When the physical sites of the tenants are scattered at different positions, the EVPN can provide two-layer interconnection for the same subnet of the same tenant based on the existing service provider or enterprise IP network.

BFD (Bidirectional Forwarding Detection) is a universal, standardized, medium-independent and protocol-independent rapid fault Detection mechanism for detecting the communication state of Forwarding paths and ensuring that communication faults can be rapidly detected between devices so as to take measures in time and ensure the continuous operation of services. BFD may quickly detect a failure of a bidirectional forwarding path between two devices for various upper layer protocols, such as routing protocols. The upper layer protocol usually adopts a Hello message mechanism to detect faults, the required time is in the order of seconds, and the BFD can provide millisecond detection.

SR (Segment Routing): a source node path selection mechanism is adopted, SID (Segment Identifier) of a Segment to be passed by a path is packaged in the source node in advance, and when a message passes through an SR node, the node forwards the message according to the SID of the message.

The device PE1 and the device PE2 are connected to the device PE3 through the intermediate device P, respectively, there is only one link between the device P and the device PE3, and the public network tag is used to indicate next-hop information, so that the public network tags of messages going to the PE3 via the P device are the same. At this time, PE1 and PE2 both use the private network tag 1150 notified by PE3 to go to other devices under PE3, so that the situation that the public network tag and the private network tag are completely consistent occurs, and PE3 cannot distinguish whether the corresponding message is sent to it by PE1 or PE2, which may cause that the BFD detection function cannot be implemented on EVPN VPLS networking.

Disclosure of Invention

In view of this, the present disclosure provides a message transmission method, a message transmission apparatus, an electronic device, and a machine-readable storage medium to solve the problem that the PE device cannot identify a message source.

The specific technical scheme is as follows:

the present disclosure provides a packet transmission method, applied to a PE device, the method including:

receiving a message to be forwarded;

updating an identity label field in a message to be forwarded, wherein the identity label field contains information for uniquely identifying local equipment;

and forwarding the message to be forwarded so that the opposite-end PE equipment can identify the sending-end PE equipment of the message according to the identity label field.

As a technical scheme, the message to be forwarded is an MPLS message;

the updating the identity label field in the message to be forwarded includes:

and updating the value of the identity Label field in the MPLS Label field of the message to be forwarded.

As a technical solution, the message to be forwarded is an SRv6 message;

the updating the identity label field in the message to be forwarded includes:

and updating the value of the identity label field in the Function field of the message to be forwarded.

As a technical solution, the message to be forwarded is a VXLAN message;

the updating the identity label field in the message to be forwarded includes:

and updating the value of the identity label field in the reserved field of the message to be forwarded.

The present disclosure also provides a packet transmission apparatus, which is applied to a PE device, and the apparatus includes:

the receiving unit is used for receiving the message to be forwarded;

the processing unit is used for updating an identity label field in the message to be forwarded, wherein the identity label field contains information for uniquely identifying the local equipment;

and the forwarding unit is used for forwarding the message to be forwarded so that the opposite-end PE equipment can identify the sending-end PE equipment of the message according to the identity label field.

As a technical scheme, the message to be forwarded is an MPLS message;

the updating the identity label field in the message to be forwarded includes:

As a technical solution, the message to be forwarded is an SRv6 message;

the updating the identity label field in the message to be forwarded includes:

As a technical solution, the message to be forwarded is a VXLAN message;

the updating the identity label field in the message to be forwarded includes:

The present disclosure also provides an electronic device, which includes a processor and a machine-readable storage medium, where the machine-readable storage medium stores machine-executable instructions capable of being executed by the processor, and the processor executes the machine-executable instructions to implement the foregoing message transmission method.

The present disclosure also provides a machine-readable storage medium having stored thereon machine-executable instructions that, when invoked and executed by a processor, cause the processor to implement the aforementioned message transmission method.

The technical scheme provided by the disclosure at least brings the following beneficial effects:

and adding a unique and exclusive equipment label in the forwarded message, so that the PE equipment of the opposite end can identify the source of the received message, and the BFD detection function can be realized.

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 of the present disclosure or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments described in the present disclosure, and other drawings can be obtained by those skilled in the art according to the drawings of the embodiments of the present disclosure.

Fig. 1 is a flowchart of a message transmission method in an embodiment of the present disclosure;

fig. 2 is a flowchart of a message transmission method in an embodiment of the present disclosure;

FIG. 3 is a hardware block diagram of an electronic device in one embodiment of the disclosure;

FIG. 4 is a schematic diagram of networking in one embodiment of the present disclosure;

fig. 5 is a schematic networking diagram in an embodiment of the present disclosure.

Detailed Description

The terminology used in the embodiments of the present disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used in this disclosure and the claims, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term "and/or" as used herein is meant to encompass any and all possible combinations of one or more of the associated listed items.

It is to be understood that although the terms first, second, third, etc. may be used herein to describe various information in the embodiments of the present disclosure, such information should not be limited by these terms. These terms are only used to distinguish one type of information from another. For example, first information may also be referred to as second information, and similarly, second information may also be referred to as first information, without departing from the scope of the present disclosure. Depending on the context, moreover, the word "if" as used may be interpreted as "at … …" or "when … …" or "in response to a determination".

In recent years, the number and scale of data centers have been on the rise explosively. Data center services are increasing day by day, user requirements are increasing day by day, and the problems that the functions of the data center are becoming complex and the operation and maintenance management difficulty is becoming higher and higher. Due to comprehensive consideration of data disaster recovery, enterprise branch establishment, resource utilization rate improvement and the like, an informatization system of a large enterprise may be deployed in a plurality of physical regions. The data center sites need to be interconnected, the management cost of the data center can be reduced, the data center service can be flexibly expanded, and the like.

Prior to the advent of EVPN, the L2 VPN standard for data center interconnect was proposed early, including:

RFC4447 proposes LDP-based VPWS (virtual Private Wire service)

RFC4762 proposes VPLS (virtual Private LAN service) based on LDP

RFC4761 proposes VPLS based on BGP

The main limitation of VPLS technology is the requirement that MPLS networks be required between sites. The configuration is complex and the maintenance workload is large. Especially, when the extended LDP is used as a signaling protocol, the problem of N square in configuration exists, and the LDP neighbors are newly configured on all existing sites PE at the same time when a new site is expanded each time. In addition, the control plane of the VPLS is established by flooding, which is inefficient and wastes wide area network bandwidth.

Modern data center setups place higher demands on the following aspects:

and (3) expandability: the expandability mainly means that the expandability can reach a certain scale in the aspects of the number of interconnected stations, the number of expanded VLANs and the MAC address capacity. For example, the system can support interconnection of more than hundreds of sites, tens of thousands of VLAN extensions and millions of MAC addresses so as to meet the requirements of large-scale and super-large-scale data centers and mass virtual machine migration.

High bandwidth utilization: wide area network bandwidth resources between data centers are typically leased and need to be efficiently utilized. The redundant deployment of the data center interconnection equipment can cause a plurality of connection paths among the data centers, and the traffic needs to be uniformly distributed on all available links so as to improve the utilization rate of wide area network bandwidth resources and save the bandwidth renting cost.

The operation and maintenance are simplified: the data center interconnection scheme generally involves protocol deployment on the network side, and the traditional deployment mode needs to implement full connection configuration of sites on the network side, so that the configuration of existing sites is also affected when interconnection sites are newly added or deleted. In order to simplify operation and maintenance, the interconnection scheme needs to realize Single-site deployment, that is, the configuration of the existing sites is not affected when the sites are newly added or deleted, and the operation and maintenance management difficulty is reduced.

The EVPN is proposed by referring to the framework of BGP/MPLS L3 VPN (RFC4364) on the basis of the existing BGP VPLS (RFC4761) scheme. In the SDN architecture, control and data are separated, and the application is constructed on a control layer. For EVPN, the control layer is MP-BGP, and EVPN can be viewed as an application built on MP-BGP. EVPN is not just a technology and architecture, it also has the implications of an application scenario. In the EVPN architecture, MAC/IP address learning between PEs is based on the control plane, advertising the reachability of MAC/IP using MP-BGP protocol, with policy control very similar to IP VPN. The learning based on the control plane can provide stronger control capability for the learning process of the MAC/IP, thereby having better expansibility, maintaining the isolation between the host and the virtual machine group, solving the load sharing problem when the equipment is accessed in a multi-homing way or the network is accessed in a multi-homing way, and improving the convergence time when the network fails.

A multihomed site is a site connected to multiple PEs through different Ethernet links, where the links form an ES (Ethernet Segment) and identify that the sites belong to the same ES by using the same esi (ES identifier). The connected multiple PEs form a redundancy backup group, so that the influence of single point failure of the PE on the network can be avoided, and the reliability of the network is improved. Only dual homing is currently supported.

The common VPLS distributes labels according to the PW, namely a PW private network label; although EVPN VPLS simplifies the configuration, the way it assigns tags changes. The EVPN VPLS is allocated with EVPN labels according to VSI, namely a plurality of PWs correspond to an EVPN private network label, and the logic of the EVPN VPLS is different from that of each PW private network label of the common VPLS. Therefore, when performing BFD detection of the EPVN VPLS networking, a situation that the PE node cannot distinguish the source of the BFD packet may be encountered. An EVPN VP LS networking is configured as shown in fig. 4, and PW is established for PE3 and PE1, PE2, respectively.

After the PE1 and PE3 devices configure VSI instances, the two devices locally generate EVPN TYPE 3 routes (Inclusive Multicast Ethernet Tag routes) and advertise to each other through MP-BGP, and it can be seen that PE3 sends EVPN TYPE 3 routes to PE1, and assigns a label 1150, which informs the other end that the tunnel end point is 3.3.3.9.

After receiving the three types of routes, PE1 checks whether the RTs in the route are consistent with their import RTs, all are 1:1, if so, receives and checks whether the Encapsulation type (Encapsulation) of the route is MPLS, if so, forms PW, and can see that PE1 also sends a similar message to PE3, and advertises that the label of the other party to PE1 is 1406.

PE3 sends the message private network label to PE2 again 1150. This means that PE3 tells the devices that the private network label of 1150 is to go to the Site configured by PE 3.

When P devices exist among PE1, PE2, and PE3, there is only one link, and the public network tag is used to indicate next hop information, so that the public network tags of messages going to PE3 via the P devices are the same. At this time, PE1 and PE2 both use the private network tag 1150 notified by PE3 to go to Site 2 under PE3, so that a situation occurs in which the public network tag and the private network tag are completely consistent, and PE3 cannot distinguish whether the corresponding message is sent to it by PE1 or PE2, which is why the BFD detection function has not been implemented in the EVPN VPLS networking, and for the EVPN VPLS networking, the link detection function is still in an empty state.

For a PE connected to a redundant backup group, it cannot determine which device in the redundant backup group the source of the packet is, and therefore cannot implement the point-to-point link detection functions such as BFD and CFD.

The specific technical scheme is as follows.

In an embodiment, the present disclosure provides a packet transmission method, applied to a PE device, where the method includes: receiving a message to be forwarded; updating an identity label field in a message to be forwarded, wherein the identity label field contains information for uniquely identifying local equipment; and forwarding the message to be forwarded so that the opposite-end PE equipment can identify the sending-end PE equipment of the message according to the identity label field.

Specifically, as shown in fig. 1, the method comprises the following steps:

and step S11, receiving the message to be forwarded.

Step S12, updating an identity tag field in the packet to be forwarded, where the identity tag field contains information uniquely identifying the local device.

And step S13, forwarding the message to be forwarded.

In one embodiment, the message to be forwarded is an MPLS message; the updating the identity label field in the message to be forwarded includes: and updating the value of the identity Label field in the MPLS Label field of the message to be forwarded.

When the BGP Update message interacts with EVPN TYPE 3 TYPE routing, the PMSI _ TUNNEL _ ATTRIBUTE ATTRIBUTE in the BGP Update message carries label information, and in addition, the link detection function can be realized without independently transforming the BFD message.

The original PMSI _ channel _ ATTRIBUTE structure includes a Flags field, a TUNNEL Type field, an MPLSLabel field, and a TUNNEL Identifier field. The high-order 20bits in the MPLS Label are Label values, the MPLS Label is an MPLS Label with two layers, one layer is used for distributing EVPN labels based on VSI, the other layer is used for identifying equipment, the high-order 20bits are used for filling the Label values, the low-order 4bits are used for identifying Label types, the low-order value of 0 is represented as an EVPN private network Label, namely the Label distributed by each VSI, the value of 1 is represented as an Identifier Label, namely the Label used for identifying different PEs sent to the equipment.

As shown in fig. 5, for a situation where one device assigns tags to multiple devices, for example, when PE3 notifies PE1 of an Identifier tag, a layer of tag 1171 is assigned to identify PE1, and at this time, tag 1171 is in an occupied state on PE 3; when PE3 announces a tag to PE2, a tag of 1172 is additionally assigned so that different devices are announced different tags. At this time, the packets from PE1 and PE2 to PE3 carry one more label than the original packets, and when the packets from two sources are sent to PE3 via P, there is a label 1171 (or 1172) for identifying the source of the device, although the original label 1150 assigned to the VSI is the same.

Other fields in the message can be modified in the same or similar way to achieve the same technical effect.

In one embodiment, the message to be forwarded is an SRv6 message; the updating the identity label field in the message to be forwarded includes: and updating the value of the identity label field in the Function field of the message to be forwarded.

IPv6 SR (SRv6) means that in an IPv6 network, a message is forwarded using SR and an IPv6 address as an SID.

SRv6 Segment is a 128-bit number, and may also be referred to generally as SRv6 SID or SID. The SID is an instantiated IPv6 address, and such IPv6 addresses are given unique functionality, e.g., a SRv6 SID may represent a node/link, or an L2/L3 VPN, or a service. The network function may be defined by the SRv6 SID.

The SRv6 SID is a network Instruction (Instruction) that consists of two parts, Locator and Function.

The Locator is primarily responsible for routing functions and is therefore unique within the SR domain. After the node configures the Locator, the system generates a Locator network segment route and diffuses in the SR domain through IGP. Other nodes in the network can be positioned to the node through the Locator network segment route, and simultaneously, all SRv6 SIDs issued by the node can also reach through the Locator network segment route.

The Function represents instructions (Instruction) of the device, which are preset by the device, and the Function part is used for instructing SRv6 the generation node of the SID to perform corresponding functional operations.

The Function part can also separate an optional parameter section (extensions), at this time, the format of SRv6 SID is changed into Locator: Function: extensions, which occupies low bit of IPv6 address, and some message stream and service information can be defined by the extensions field. Both Function and definitions are definable, which also reflects the SRv6 SID's structure that is more conducive to programming the network.

The Function field is used for detecting and identifying whether the message is a source or a destination, and the message source is identified by taking a layer of label through the definitions field.

In an embodiment, the message to be forwarded is a VXLAN message; the updating the identity label field in the message to be forwarded includes: and updating the value of the identity label field in the reserved field of the message to be forwarded.

The encapsulation format of the VXLAN message is as follows: an 8 byte VXLAN header, an 8 byte UDP header, and a 20 byte IP header are added outside the two layer data frame. Wherein the destination port number of the UDP header is VXLAN UDP port number (4789 by default). The VXLAN head mainly comprises two parts: a marker bit and a VXLAN ID.

A flag bit, the "I" bit being 1, indicates that the VXLAN ID in the VXLAN header is valid; a value of 0 indicates that the VXLAN ID is invalid. The other bits remain unused and are set to 0.

The VXLAN ID is used to identify a VXLAN network and is 24 bits in length.

Through the stage of establishing PW by using EVPN TYPE 3 TYPE route interaction among devices, a mode of adding a layer of MPLS label in the attribute of a BGP Update message or a mode of modifying SRv6 SID identification source and purpose and modifying VXLAN reserved field tape label is adopted to realize the identification capability of the devices to the message source, so that detection functions such as BFD, CFD and the like can develop application in an EVPN VPLS multi-attribution network

In an embodiment, as shown in fig. 2, the present disclosure also provides a packet transmission apparatus, applied to a PE device, where the apparatus includes: a receiving unit 21, which receives a message to be forwarded; the processing unit 22 updates an identity tag field in the message to be forwarded, wherein the identity tag field contains information uniquely identifying the local device; and the forwarding unit 23 is configured to forward the packet to be forwarded, so that the peer PE device identifies the sending-end PE device of the packet according to the identity tag field.

The device embodiments are the same or similar to the method embodiments and are not described in detail herein.

In an embodiment, the present disclosure provides an electronic device, including a processor and a machine-readable storage medium, where the machine-readable storage medium stores machine-executable instructions capable of being executed by the processor, and the processor executes the machine-executable instructions to implement the foregoing message transmission method, and from a hardware level, a schematic diagram of a hardware architecture may be as shown in fig. 3.

In one embodiment, the present disclosure provides a machine-readable storage medium having stored thereon machine-executable instructions that, when invoked and executed by a processor, cause the processor to implement the aforementioned messaging method.

Here, a machine-readable storage medium may be any electronic, magnetic, optical, or other physical storage device that can contain or store information such as executable instructions, data, and so forth. For example, the machine-readable storage medium may be: a RAM (random access Memory), a volatile Memory, a non-volatile Memory, a flash Memory, a storage drive (e.g., a hard drive), a solid state drive, any type of storage disk (e.g., an optical disk, a dvd, etc.), or similar storage medium, or a combination thereof.

The systems, devices, modules or units described in the above embodiments may be implemented by a computer chip or an entity, or by a product with certain functions. A typical implementation device is a computer, which may take the form of a personal computer, laptop computer, cellular telephone, camera phone, smart phone, personal digital assistant, media player, navigation device, email messaging device, game console, tablet computer, wearable device, or a combination of any of these devices.

For convenience of description, the above devices are described as being divided into various units by function, and are described separately. Of course, the functionality of the various elements may be implemented in the same one or more software and/or hardware implementations in practicing the disclosure.

As will be appreciated by one skilled in the art, embodiments of the present disclosure may be provided as a method, system, or computer program product. Accordingly, the present disclosure may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, embodiments of the present disclosure may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and so forth) having computer-usable program code embodied therein.

The present disclosure is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the disclosure. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

Furthermore, these computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

As will be appreciated by one skilled in the art, embodiments of the present disclosure may be provided as a method, system, or computer program product. Accordingly, the present disclosure may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present disclosure may take the form of a computer program product embodied on one or more computer-usable storage media (which may include, but is not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

The above description is only an embodiment of the present disclosure, and is not intended to limit the present disclosure. Various modifications and variations of this disclosure will be apparent to those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present disclosure should be included in the scope of the claims of the present disclosure.

Claims

1. A message transmission method is applied to PE equipment, and is characterized in that the method comprises the following steps:

receiving a message to be forwarded;

and forwarding the message to be forwarded so that the opposite-end PE device connected through the network device can identify the sending-end PE device of the message according to the identity label field.

2. The method according to claim 1, wherein the packet to be forwarded is an MPLS packet;

the updating the identity label field in the message to be forwarded includes:

3. The method according to claim 1, wherein the message to be forwarded is an SRv6 message;

the updating the identity label field in the message to be forwarded includes:

4. The method according to claim 1, wherein the message to be forwarded is a VXLAN message;

the updating the identity label field in the message to be forwarded includes:

5. A message transmission device is applied to PE equipment, and the device comprises:

the receiving unit is used for receiving the message to be forwarded;

and the forwarding unit is used for forwarding the message to be forwarded so that the opposite-end PE equipment connected through the network equipment can identify the sending-end PE equipment of the message according to the identity label field.

6. The apparatus according to claim 5, wherein the packet to be forwarded is an MPLS packet;

the updating the identity label field in the message to be forwarded includes:

7. The apparatus according to claim 5, wherein the message to be forwarded is SRv6 message;

the updating the identity label field in the message to be forwarded includes:

8. The apparatus according to claim 5, wherein the message to be forwarded is a VXLAN message;

the updating the identity label field in the message to be forwarded includes:

9. An electronic device, comprising: a processor and a machine-readable storage medium storing machine-executable instructions executable by the processor to perform the method of any one of claims 1 to 4.

10. A machine-readable storage medium having stored thereon machine-executable instructions which, when invoked and executed by a processor, cause the processor to implement the method of any of claims 1-4.