CN112039765B

CN112039765B - Method for transmitting route information, method and device for selecting route

Info

Publication number: CN112039765B
Application number: CN201910476154.0A
Authority: CN
Inventors: 张鹏
Original assignee: ZTE Corp
Current assignee: ZTE Corp
Priority date: 2019-06-03
Filing date: 2019-06-03
Publication date: 2023-05-30
Anticipated expiration: 2039-06-03
Also published as: CN112039765A; WO2020244304A1

Abstract

A method for transmitting route information, a method and a device for selecting route, wherein a first node determines the master and slave states of the first node; and the first node sends the route information carrying the main and standby information according to the main and standby state. The second node receives the routing information from the first node; and the second node preferentially selects the route containing the active node according to the active and standby information. By the embodiment of the invention, the possibility that the remote PE is likely to be optimized to the non-DF equipment during the route selection is avoided, and the optimal route of the DF equipment is always optimized in the control layer, thereby avoiding the condition of service interruption caused by route selection errors due to configuration or network change and the like.

Description

Method for transmitting route information, method and device for selecting route

Technical Field

This document relates to, but is not limited to, a method of routing information transmission, a method of routing, an apparatus, a node, and a computer readable storage medium.

Background

The VPLS (Virtual Private LAN Service ) technology belongs to a two-Layer packet bearer technology, and is an L2VPN (Layer 2Virtual Private Network, two-Layer virtual private network) technology based on IP/MPLS (Internet Protocol/Multi-Protocol Label Switching, internet protocol/multiprotocol label switching) and ethernet technologies. The core idea is to build and maintain PW (Pseudo Wire) between PEs (Provider Edge Node, operator edge nodes) in VPLS instance by using signaling protocol, encapsulate two-layer protocol frames and transmit and exchange over PW, so that multiple local area networks in wide area are integrated into one network at data link level, and virtual ethernet service is provided for users. The VPLS technology effectively combines the characteristics of various technologies such as IP/MPLS, L2VPN Ethernet exchange and the like, supports the service types of point-to-point, point-to-multipoint and multipoint-to-multipoint, and can support carrier grade Ethernet service under a larger network scale.

EVPN (Ethernet Virtual Private Network ) is a data center interconnection technology based on Overlay technology. In EVPN, MAC/IP (Media Access Control/Internet Protocol ) address learning between PEs is control plane based, with MP-BGP (MultiProtocol Border Gateway Protocol ) advertising reachability of MAC/IP, policy control very similar to IP VPN (Virtual Private Network ). The learning based on the control plane can provide stronger control capability for the learning process of the MAC/IP, so the learning method has better expansibility, can maintain the isolation between the hosts or virtual machine groups, solves the problem of load sharing when the equipment is multi-homed or the network is multi-homed, and improves the convergence time when the network fails.

In order to increase the bandwidth utilization of the links and to enhance the network reliability, a CE (Customer Edge device, user edge device) may be connected to a plurality of PEs through a plurality of links, which is called multi-homing access, abbreviated multi-homing access. When one CE is connected to two or more PEs in multiple ways, and only one PE in the PEs can forward traffic with the CEs, the scenario is called a Single-Active mode; when a CE is multi-connected to two or more PEs, and All PEs in the PEs are capable of forwarding traffic with the CE, this scenario is referred to as All-Active multi-Active mode.

As shown in fig. 1, in the VPLS EVPN multi-homing scenario, CE2 multi-homing accesses PE2 and PE3, a Single-Active mode is configured between PE2 and PE3, at this time, only one PE is selected between PE2 and PE3 as a DF (Designated Forwarder, designated transponder) for traffic forwarding, CE2 is configured as a primary mode, and the primary mode is connected to DF, and the secondary link is connected to non-DF.

In this scenario, PE2 and PE3 may issue BGP (Border Gateway Protocol ) EVPN RT-1per-EVI Route (per-EVI Ethernet a-D Route) of the VPLS instance to the EVPN neighbor, and after receiving the RT-1per-EVI Route issued by PE2 and PE3, the remote PE1 may directly perform Route optimization according to BGP Route selection rules.

If the BGP optimal route is a non-DF device at this time, traffic from CE1 to CE2 is sent to the non-DF and forwarded from the non-DF AC port to the backup link of the CE, resulting in traffic interruption caused by the dropped traffic.

Disclosure of Invention

The following is a summary of the subject matter described in detail herein. This summary is not intended to limit the scope of the claims.

The embodiment of the invention provides a method for sending route information, a method for selecting route, a device, a node and a computer readable storage medium for avoiding that PE is preferably selected to non-DF equipment during route selection.

The embodiment of the invention provides a method for sending routing information, which comprises the following steps:

the method comprises the steps that a first node determines own main and standby information, wherein the main and standby information comprises information that the first node is a main node, a standby node or neither the main node nor the standby node;

the first node transmits routing information carrying the primary and backup information.

The embodiment of the invention also provides a routing method, which comprises the following steps:

the second node receives the routing information from the first node; the routing information carries main and standby information of the first node, wherein the main and standby information comprises information that the first node is a main node, a standby node or neither the main node nor the standby node;

and the second node preferentially selects the route containing the active node according to the active and standby information.

The embodiment of the invention also provides a device for sending the routing information, which comprises the following steps:

the device comprises a determining module, a judging module and a judging module, wherein the determining module is used for determining main and standby information of the device, and the main and standby information comprises information that the device is a main node, a standby node or neither the main node nor the standby node;

and the sending module is used for sending the route information carrying the main and standby information.

The embodiment of the invention also provides a routing device, which comprises:

a receiving module, configured to receive routing information from a first node; the routing information carries main and standby information of the first node, wherein the main and standby information comprises information that the first node is a main node, a standby node or neither the main node nor the standby node;

and the routing module is used for preferentially selecting the route containing the active node according to the active and standby information.

The embodiment of the invention comprises the following steps: the first node determines the main and standby states of the first node; and the first node sends the route information carrying the main and standby information according to the main and standby state. The second node receives the routing information from the first node; and the second node preferentially selects the route containing the active node according to the active and standby information. By the embodiment of the invention, the possibility that the remote PE is likely to be optimized to the non-DF equipment during the route selection is avoided, and the optimal route of the DF equipment is always optimized in the control layer, thereby avoiding the condition of service interruption caused by route selection errors due to configuration or network change and the like.

Other aspects will become apparent upon reading and understanding the accompanying drawings and detailed description.

Drawings

FIG. 1 is a schematic diagram of a multiple access;

fig. 2 is a flow chart of a method of routing information transmission according to an embodiment of the present invention;

fig. 3 is a schematic diagram of a flag bit inserted in BGP routing information according to an embodiment of the present invention;

fig. 4 is a schematic diagram of setting conditions of a flag bit in multiple different scenes of a VPLS EVPN according to an embodiment of the present invention;

FIG. 5 is a flow chart of a method of routing according to an embodiment of the present invention;

fig. 6 is a schematic diagram of BGP routing rules of a remote PE receiving a flag bit in a VPLS EVPN multi-homing scenario provided by an embodiment of the present invention;

fig. 7 is a schematic diagram of the apparatus for transmitting routing information according to an embodiment of the present invention;

FIG. 8 is a schematic diagram of the composition of a routing device according to an embodiment of the present invention;

fig. 9 is a schematic diagram of the composition of a node according to an embodiment of the present invention.

Detailed Description

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The steps illustrated in the flowchart of the figures may be performed in a computer system, such as a set of computer-executable instructions. Also, while a logical order is depicted in the flowchart, in some cases, the steps depicted or described may be performed in a different order than presented herein.

As shown in fig. 2, a method for sending routing information according to an embodiment of the present invention includes:

in step 101, the first node determines own master and slave information.

The primary and standby information comprises information that the first node is a primary node, a standby node or neither a primary node nor a standby node.

The first node may refer to a PE that issues a route.

In an embodiment, the step 101 may include:

and the first node determines own active and standby information according to the mode or the mode and the own active and standby state, wherein the mode comprises a multi-active mode and a single-active mode.

In the multi-activity mode, the first node can determine the main and standby information of the first node according to the mode; in the single active mode, the first node determines own active-standby information according to the combination of the mode and the active-standby state.

The primary and secondary information may include information of a primary identification bit (abbreviated as P) and information of a secondary identification bit (abbreviated as B).

In the multi-active mode, all nodes can be considered as active nodes, the first node determines that the active identification bit is 1, and the standby identification bit is 0.

In the single active mode, according to the active/standby state of the first node, the following three situations are classified:

1. when the first node is a main node, the first node determines that the main identification bit is 1, and the standby identification bit is 0; the first node is DF at this time.

2. When the first node is a standby node, the first node determines that the main identification bit is 0, and the standby identification bit is 1; the first node is now non-DF.

3. When the first node is neither the active node nor the standby node, the first node determines that the active flag bit is 0 and the standby flag bit is 0. The first node is now non-DF.

Since the receiving node (second node) may select a route based on the primary identification bits only, in other embodiments, the primary and secondary information may also include only the information of the primary identification bits.

Step 102, the first node sends routing information carrying the primary and backup information.

In an embodiment, the routing information includes BGP routing information, and the step 102 includes:

and the first node adds the main and standby information into the extended community attribute in the BGP routing information and sends the routing information.

In an embodiment, the primary and standby information includes information of a primary identification bit and information of a standby identification bit, and the first node adds the information of the primary identification bit and the information of the standby identification bit to a control flag field in the extended community attribute.

Fig. 3 is a schematic diagram of a flag bit inserted in BGP routing information according to an embodiment of the present invention, as shown in fig. 2:

when the VPLS EVPN is a multi-homing scenario, in the path attribute of BGP RT-1per-EVI route, a Layer2Info Extended Community extended community attribute (RFC 4761) is carried, and referring to fig. 3, the extended community attribute includes an extended community type, an encapsulation type, a control flag, a Layer 2MTU (Maximum Transmission Unit ), and a reserved field.

There is a Control Flags field of 1 byte in the extended community attribute. The field is the original MBZ (Must Be Zero, must Be 0), C and S flag bits, C represents whether Control Word (Control Word) is enabled, S field represents whether sequential send frame is enabled (Sequenced delivery of frames). The flag bit shown in fig. 3 is newly added in this field. Wherein,,

the P flag bit is 1, which indicates that PE of the release route is Primary PE (Primary PE);

a flag bit of 1 indicates that the PE of the release route is a Back-up PE (standby PE).

Fig. 4 is a schematic diagram of setting conditions of a flag bit in multiple different scenarios of VPLS EVPN according to an embodiment of the present invention, as shown in fig. 4:

1) When the inter-PE configuration is in All-Active multi-Active mode, it is indicated that All PE devices connected to the same CE device are capable of traffic forwarding.

At this time, the P flag position 1 and the B flag position 0 of all PE devices, and the RT-1per-EVI route containing the flag bit is issued to the corresponding EVPN neighbors. At this point if the B flag is at position 1, the receiving device ignores this flag.

2) When the inter-PE configuration is in a Single-Active mode, it is indicated that only Primary PE (DF) equipment in all PE equipment connected to the same CE equipment allows traffic forwarding, and other non-DF equipment does not forward traffic.

At the moment, the DF equipment P mark position 1 and the B mark position 0 of the Primary PE; the non DF equipment P mark position 0 and the B mark position 1 of the Back-up PE; the P mark position 0 and the B mark position 0 of the rest PE equipment; and the RT-1per-EVI route containing the flag bit is issued to the corresponding EVPN neighbor.

As shown in fig. 5, a routing method in an embodiment of the present invention includes:

step 201, the second node receives the route information from the first node; the route information carries the primary and standby information of the first node.

In an embodiment, the routing information includes BGP routing information, and the primary and secondary information is located in an extended community attribute in the BGP routing information.

Referring to fig. 3, in an embodiment, the primary and secondary information includes primary and secondary identification bit information, which are located in a control flag field in the extended community attribute.

Step 202, the second node preferentially selects a route including the active node according to the active-standby information.

That is, the second node preferentially selects the route with the primary identification bit of 1. And when the main identification bit is 0 or the same, the route can be selected according to the original route selection rule.

Referring to fig. 6, in order to provide a schematic diagram of BGP routing rules with flag bits received by a remote PE in a VPLS EVPN multi-homing scenario according to an embodiment of the present invention, the method includes the following steps:

step 301, when the remote PE device receives the RT-1per-EVI route with the flag bit according to the scenario shown in fig. 4, it first prefers the route of the P flag bit 1, and if the P flag bit is 0 or the same, it executes the next step;

step 302, a route with the largest weight value is prioritized;

step 303, preferring the route with the largest local_preference (Local priority);

wherein local_preference is used to advertise the priority of the route, exchanging only between IBGP (Internal Border Gateway Protocol, interior border gateway protocol) peers;

step 304, preferably, the shortest as_path route;

step 305, preferably aggregate routing;

step 306, sequentially selecting routes with Origin attribute IGP (Interior Gateway Protocol ), EGP (Exterior Gateway Protocol, exterior gateway protocol), incomplete;

step 307, preferably the route with the lowest MED (metric value);

step 308, sequentially selecting routes learned from EBGP (External Border Gateway Protocol ), federation, IBGP (Interior Border Gateway Protocol, internal border gateway protocol);

step 309, preferably the route with the smallest next hop cost value;

step 310, preferred Cluster_List (Cluster List) shortest route;

step 311, preferred router_id (first identification) minimum route;

step 312, preferably, the Router published by the Router with the smallest Router ID (Router identification);

in step 313, the route issued by the peer with the smallest address is preferred.

Steps 302 to 313 are selecting routes according to the current supported original BGP routing rules. The optimal route of the far-end PE can be ensured to always be optimized to DF equipment through the step 301, and the normal forwarding of the traffic is ensured.

By the embodiment of the invention, the possibility that the remote PE is likely to be optimized to the non-DF equipment during the route selection is avoided, and the optimal route of the DF equipment is always optimized in the control layer, thereby avoiding the condition of service interruption caused by route selection errors due to configuration or network change and the like.

As shown in fig. 7, an embodiment of the present invention further provides a device for sending routing information, including:

a determining module 401, configured to determine primary and backup information of the device, where the primary and backup information includes information that the device is a primary node, or a backup node, or is neither a primary node nor a backup node;

and a sending module 402, configured to send routing information carrying the primary and standby information.

In an embodiment, the determining module 401 is configured to:

and determining own active and standby information according to the mode of the device or the mode and the active and standby state of the device, wherein the mode comprises a multi-active mode and a single-active mode.

In an embodiment, the primary and secondary information includes information of a primary identification bit and information of a secondary identification bit, and the determining module 401 is configured to:

in a multi-activity mode, determining that the main identification bit is 1, and determining that the standby identification bit is 0;

in a single active mode, when the device is a main node, determining that the main identification bit is 1, and the standby identification bit is 0;

in a single active mode, when the device is a standby node, determining that the main identification bit is 0 and the standby identification bit is 1;

in the single active mode, when the device is neither a primary node nor a standby node, the primary identification bit is determined to be 0, and the standby identification bit is determined to be 0.

In an embodiment, the routing information includes border gateway protocol BGP routing information, and the sending module 402 is configured to:

and adding the main and standby information into the extended community attribute in the BGP routing information, and sending the routing information.

In an embodiment, the primary and secondary information includes information of a primary identification bit and information of a secondary identification bit, and the sending module 402 is configured to:

and adding the information of the main identification bit and the information of the standby identification bit into a control mark field in the extended group attribute.

As shown in fig. 8, an embodiment of the present invention further provides a routing device, including:

a receiving module 501, configured to receive routing information from a first node; the routing information carries main and standby information of the first node, wherein the main and standby information comprises information that the first node is a main node, a standby node or neither the main node nor the standby node;

and the routing module 502 is configured to preferentially select a route including the active node according to the active and standby information.

In an embodiment, the primary and secondary information includes information of a primary identification bit and information of a secondary identification bit, and the information of the primary identification bit and the information of the secondary identification bit are located in a control flag field in the extended community attribute.

As shown in fig. 9, an embodiment of the present invention further provides a node, including: a memory 601, a processor 602 and a computer program 603 stored on the memory 601 and executable on the processor 602, the processor 602 implementing the above method when executing the program.

The embodiment of the invention also provides a computer readable storage medium, which stores computer executable instructions for executing the method.

In the present embodiment, the storage medium may include, but is not limited to: a U-disk, a Read-Only Memory (ROM), a random access Memory (RAM, random Access Memory), a removable hard disk, a magnetic disk, or an optical disk, or other various media capable of storing program codes.

Those of ordinary skill in the art will appreciate that all or some of the steps, systems, functional modules/units in the apparatus, and methods disclosed above may be implemented as software, firmware, hardware, and suitable combinations thereof. In a hardware implementation, the division between the functional modules/units mentioned in the above description does not necessarily correspond to the division of physical components; for example, one physical component may have multiple functions, or one function or step may be performed cooperatively by several physical components. Some or all of the components may be implemented as software executed by a processor, such as a digital signal processor or microprocessor, or as hardware, or as an integrated circuit, such as an application specific integrated circuit. Such software may be distributed on computer readable media, which may include computer storage media (or non-transitory media) and communication media (or transitory media). The term computer storage media includes both volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data, as known to those skilled in the art. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital Versatile Disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and which can be accessed by a computer. Furthermore, as is well known to those of ordinary skill in the art, communication media typically embodies computer readable instructions, data structures, program modules or other data in a modulated data signal such as a carrier wave or other transport mechanism and includes any information delivery media.

Claims

1. A method of routing information transmission, comprising:

in a VPLS EVPN multi-homing scene, a first node determines own main and standby information, wherein the main and standby information comprises information that the first node is a main node or a standby node or is neither the main node nor the standby node;

the first node sends the route information carrying the primary and standby information to a second node so that the second node preferentially selects the route containing the primary node according to the primary and standby information;

the first node determines own master and slave information, including: the first node determines own active and standby information according to the mode or the mode and the own active and standby state, wherein the mode comprises a multi-active mode and a single-active mode;

under the condition that the mode is a multi-activity mode, the main and standby information is directly determined according to the multi-activity mode; and under the condition that the mode is a single active mode, determining the main and standby information according to the single active mode and the main and standby state of the main and standby information.

2. The method of claim 1, wherein the primary and secondary information includes information of a primary identification bit and information of a secondary identification bit, and the first node determines the primary and secondary information of itself according to a mode in which the first node is located, or a mode in which the first node is located and a primary and secondary state of the first node, including: in a multi-active mode, the first node determines that the active identification bit is 1, and the standby identification bit is 0;

in a single active mode, when the first node is a primary node, the first node determines that the primary identification bit is 1, and the standby identification bit is 0;

in a single active mode, when the first node is a standby node, the first node determines that the main identification bit is 0, and the standby identification bit is 1;

in the single active mode, when the first node is neither the active node nor the standby node, the first node determines that the active flag bit is 0 and the standby flag bit is 0.

3. The method of claim 1, wherein the routing information comprises border gateway protocol BGP routing information, and wherein the first node transmits routing information carrying the primary and backup information, comprising: and the first node adds the main and standby information into the extended community attribute in the BGP routing information and sends the routing information.

4. The method of claim 3 wherein the primary and backup information includes information of primary and backup identification bits, and wherein the first node adds the primary and backup information to an extended community attribute in the BGP routing information, comprising: and the first node adds the information of the main identification bit and the information of the standby identification bit into a control mark field in the extended group attribute.

5. A method of routing, comprising:

in a VPLS EVPN multi-homing scene, a second node receives routing information from a first node; the routing information carries main and standby information of the first node, wherein the main and standby information comprises information that the first node is a main node, a standby node or neither the main node nor the standby node;

the second node preferentially selects a route containing the active node according to the active and standby information;

the method comprises the steps that the primary and standby information of a first node is determined by the first node according to a mode or a mode and a primary and standby state of the first node, wherein the mode comprises a multi-activity mode and a single-activity mode;

wherein, under the condition that the mode is a multi-activity mode, the main and standby information is directly determined according to the multi-activity mode; and under the condition that the mode is a single active mode, the main and standby information is determined according to the single active mode and the main and standby state of the main and standby information.

6. The method of claim 5, wherein,

the routing information comprises BGP routing information, and the primary and standby information is located in an extended community attribute in the BGP routing information.

7. The method of claim 6, wherein,

the main and standby information comprises information of a main identification bit and information of a standby identification bit, and the information of the main identification bit and the information of the standby identification bit are located in a control mark field in the extended group attribute.

8. An apparatus for routing information transmission, comprising:

the determining module is used for determining main and standby information of the device in a VPLS EVPN multi-homing scene, wherein the main and standby information comprises information that the device is a main node or a standby node or is neither the main node nor the standby node;

the sending module is used for sending the route information carrying the primary and standby information to the second node so that the second node can preferentially select the route containing the primary node according to the primary and standby information;

wherein, the determining the master and slave information of the device includes: determining own active and standby information according to the mode or the mode and the own active and standby state, wherein the mode comprises a multi-active mode and a single-active mode;

9. An apparatus for routing, comprising:

the receiving module is used for receiving the route information from the first node in the VPLS EVPN multi-homing scene; the routing information carries main and standby information of the first node, wherein the main and standby information comprises information that the first node is a main node, a standby node or neither the main node nor the standby node;

the routing module is used for preferentially selecting a route containing the active node according to the active and standby information;

the master-slave information of the first node is determined by the first node according to a mode or a mode and a master-slave state of the first node, wherein the mode comprises a multi-activity mode and a single-activity mode;