CN101188564B

CN101188564B - A method for realizing multi-span tree protocol

Info

Publication number: CN101188564B
Application number: CN2007101883971A
Authority: CN
Inventors: 钱锐; 邵军; 伏朝晖
Original assignee: ZTE Corp
Current assignee: ZTE Corp
Priority date: 2007-11-21
Filing date: 2007-11-21
Publication date: 2010-06-02
Anticipated expiration: 2027-11-21
Also published as: CN101188564A

Abstract

The invention discloses a realization method of MTSP, the method includes that a MSTP and a QINQ or two layers of VPN based MTSP are opened in an exchanger; spanning tree sub-case is set and spanningtree sub-case topology is acquired; and an outputting exchanger outputs user data transmitted by spanning tree sub-case topology. Before acquiring the spanning tree sub-case topology, judgement can bedo for iMSTP mode according to iMSTP ID. The adoption of the method provided in the invention not only resolves the problem that the prior MSTP protocol supplies inadequate support to the QINQ protocol and two layers of VPN protocols, but also differentiates different VLAN businesses under the two layers of the protocols, thus the expanding ability of VLAN businesses is enhanced.

Description

A kind of implementation method of Multiple Spanning Tree Protocol

Technical field

The present invention relates to the data communication field, relate in particular to a kind of implementation method of Multiple Spanning Tree Protocol.

Background technology

STP (Spanning-Tree Protocol, Spanning-Tree Protocol) has determined its characteristic as " little " agreement decision " greatly " agreement from that time of birth.Here so-called " size " is meant agreement itself, but Spanning-Tree Protocol all wants important many than any Routing Protocol, MPLS (multi protocol label exchange) agreement.

Spanning-Tree Protocol has experienced three phases in its historical development: first generation Spanning-Tree Protocol: SSTP/RSTP (simple Spanning-Tree Protocol/RSTP); Second generation Spanning-Tree Protocol: PVST/PVST+ (VLAN (VLAN) Spanning-Tree Protocol); The third generation is produced tree protocol: MSTP agreement (Multi Spanning-Tree Protocol-Multiple Spanning Tree Protocol).

Though first generation Spanning-Tree Protocol is simple, quick, but in today that IEEE 802.1Q agreement is propagated its belief on a large scale, because this agreement relates generally to the realization of VLAN, SSTP or RSTP can't distinguish the VLAN example, can not operate adhering to different VLAN business separately, first generation Spanning-Tree Protocol can not satisfy the requirement of IEEE 802.1Q agreement.

In order to solve professional helpless situation to VLAN, second generation Spanning-Tree Protocol is arisen at the historic moment, but adopt this Spanning-Tree Protocol, each VLAN will keep a spanning-tree instance, and spanning-tree instance quantity is corresponding one by one with VLAN like this, not only lacks flexibility, and when VLAN is numerous, the spanning-tree instance that need keep also can correspondingly increase, and brings very big burden to switch, has influenced the performance of switch greatly.

Third generation Spanning-Tree Protocol has solved the problem that front two generations agreement all faces, it is a kind of Multiple Spanning Tree Instance that can distinguish VLAN and can carry out multiple combination to VLAN, each spanning-tree instance is represented a series of VLAN combination, and MSTP just can solve all problems of 802.1Q agreement like this.

Along with the data communication field day by day the trend inevitable requirement of IPization different VLAN business are supported, under this trend, QINQ (or claims SVLAN, being that VLAN piles up) agreement and two-layer VPN (Virtual Private Network) agreement be born, this thought inevitable requirement Spanning-Tree Protocol with two-layer protocol differentiation different business is made Corresponding Countermeasures, has just stagnated but Spanning-Tree Protocol develops into the MSTP agreement.From the characteristics of present data communication, existing MSTP agreement can only be distinguished according to the VLAN ID of the switch ports themselves that participates in multiple spanning tree calculating, and generates the calculating of tree topology according to the mapping of different Multiple Spanning Tree Instances and VLAN ID.Dual-VLAN label protocol that relates to for the QINQ agreement or multilayer VLAN label protocol and two-layer VPN agreement need be distinguished the operation of different VLAN business and but can not support, and the professional poor expandability of VLAN, do not provide requisite space to future development.

Summary of the invention

The objective of the invention is to propose a kind of implementation method of Multiple Spanning Tree Protocol, QINQ agreement and two-layer VPN agreement are supported not enough problem in order to overcome MSTP agreement in the prior art.

In order to realize the foregoing invention purpose, the present invention specifically is achieved in that

A kind of implementation method of Multiple Spanning Tree Protocol comprises the steps:

Step 1 needs to enter switch through the data message that switch is transmitted, and switch is opened the iMSTP Multiple Spanning Tree Protocol, increases the iMSTP protocol fields in protocol massages, and according to the iMSTP protocol fields is provided with, carries out the setting that iMST generates the tree example;

Step 2 by the field that protocol massages increases, generates tree example topology and calculates;

Step 3, switch are transmitted output through generating the data message that tree example topology is transmitted.

In the wherein said step 2, calculate and generate tree example topology, comprise the steps:

Step 2a carries out the iMST pattern and judges;

Step 2b carries out regional root election;

Step 2c carries out path cost and calculates.

Among the wherein said step 2a, carry out the iMSTP pattern according to the iMSTP ID that in the iMSTP of described setting protocol fields, is provided with and judge;

The value of described iMSTP ID is to be determined by the VLAN networking mode;

If adopt the networking of QINQ mode, then iMSTP ID value is the VLAN ID of the inner VLAN label of QINQ;

If adopt the networking of two-layer VPN mode, then iMSTP ID value is to VCID value that different business distributed in the trunk value that disposed of two-layer VPN edge interface or the two-layer VPN.

The implementation method of described Multiple Spanning Tree Protocol in the described step 1, before carrying out switch unlatching iMSTP Multiple Spanning Tree Protocol, is carried out the unlatching of MSTP Multiple Spanning Tree Protocol earlier.

In the wherein said step 1, do not generate the tree example if iMST is set, then carry out MST Multiple Spanning Tree Instance topology and calculate, according to the Multiple Spanning Tree Instance topology, switch is transmitted the dateout message.

Adopt the implementation method of Multiple Spanning Tree Protocol of the present invention, not only solved existing MSTP agreement QINQ agreement and two-layer VPN agreement are supported not enough problem, can distinguish the different VLAN business under the two-layer protocol, also strengthened the autgmentability of VLAN business.

Description of drawings

Accompanying drawing described herein is used to provide further understanding of the present invention, constitutes the application's a part, and illustrative examples of the present invention and explanation thereof are used to explain the present invention, do not constitute improper qualification of the present invention.

Fig. 1 is the structured flowchart of iMST under the QINQ pattern among the present invention;

Fig. 2 is the structured flowchart of iMST under the VPLS VLAN pattern among the present invention;

Fig. 3 is the structured flowchart of iMST under the VPLS VCID pattern among the present invention;

Fig. 4 is the process chart of specific embodiments of the invention;

Fig. 5 is the system construction drawing that the IP network device systems that adopts the inventive method to form is carried out functional verification test.

Fig. 6 adopts the inventive method to transform the structural representation of the BPDU message of existing MSTP agreement.

Embodiment

The method of the invention mainly comprises the steps:

Step 1 is opened Multiple Spanning Tree Protocol MSTP and based on the Multiple Spanning Tree Protocol iMSTP (having the MSTP agreement that generates the tree example) of QINQ or two-layer VPN on switch; For the switch that does not dispose Multiple Spanning Tree Protocol iMSTP, its data message is directly transmitted according to the multiple spanning tree MST topology that has generated.

Step 2, configuration generates the tree example, obtains to generate tree example topology;

When generating the configuration of tree example, should carry out the judgement of iMSTP pattern earlier, described iMSTP pattern identifies according to iMSTP ID, because VLAN networking mode difference, the value of described iMSTP ID is also different.

If adopt the networking of QINQ mode, then need the iMSTP pattern to be set to the QINQ pattern, and the VLAN ID of the inner VLAN label of QINQ is appointed as iMSTP ID;

If adopt the networking of two-layer VPN mode, need to distinguish trunk VLAN (the two-layer VPN edge interface is configured to trunk VLAN) mode and VCID mode:

If adopt trunk VLAN mode, the trunk value that then the two-layer VPN edge interface is disposed is composed and is given iMSTP ID;

If adopt the VCID mode, then will compose to iMSTP ID in each two-layer VPN the VCID value that different business distributed;

Step 3 needs to enter switch through the data message that switch is transmitted, and transmits according to generating tree example topology, can inquire about the topology state that each generates the tree example by special order; The topology of different generation tree examples should be different.

Step 4, egress switch output is through generating the user data that tree example topology is transmitted.

The data message that belongs to different business can be transmitted according to different generation tree example topology, passes through packet parsing then, correctness, the integrality of checking message.

Below in conjunction with accompanying drawing specific embodiments of the invention are described in further detail.

As shown in Figure 4, iMSTP handling process among the present invention may further comprise the steps:

Step 401, switch are received the user data message;

Step 402, switch judge whether to open the MSTP Multiple Spanning Tree Protocol, if, then change step 403 over to, otherwise, change step 408 over to;

Step 403, switch judge whether to open the iMSTP Multiple Spanning Tree Protocol, if, then change step 404 over to, otherwise, change step 406 over to;

In described step 402 or the step 403, opening Multiple Spanning Tree Protocol (MSTP or iMSTP) is to realize like this, promptly enable the Multiple Spanning Tree Instance on the switch, under the switch global configuration mode, (for example: enable spanning-tree) open an enable command; Carry out this order then and (for example: spanning-tree mode MSTP) specify spanning-tree mode (MSTP or iMSTP).

Step 404 increases the iMSTP protocol fields in the iMSTP protocol massages, according to the setting to the iMSTP protocol fields, switch generates the tree example and judges whether iMST is set, if, then change step 405 over to, otherwise, change step 406 over to;

The described iMST sub-instance that is provided with, be meant in switching network, to increase and generate seeds class iMST, iMST and MST, SST and RST are separate, then should in switch, increase the pattern that iMST is supported, it is the iMSTP pattern, but the configuration of iMSTP and MSTP (i.e. topology) is separate and can coexist.

Step 405 enters iMST multiple spanning tree negotiation mode, calculates to generate tree example topology, changes step 407 then over to;

Described calculating generates tree example topology, comprises the steps:

Step 5a carries out the iMSTP pattern and judges;

Step 5b carries out regional root election;

Step 5c carries out path cost and calculates.

Step 406 enters MST multiple spanning tree negotiation mode, calculates the spanning-tree instance topology;

Described calculating spanning-tree topology comprises the steps:

Step 6a carries out regional root election;

Step 6b carries out path cost and calculates.

Step 407, switch protocol layer notice Drive Layer generates the forwarding passage by the topological structure that has calculated;

Step 408, switch is transmitted through the user data message after the topology.

As shown in Figure 6, with the QINQ agreement is example, for the support of iMSTP agreement can be provided, at the QINQ interface, transform BPDU (bridge protocol data unit) message of existing MSTP agreement, iMSTP (Inside MSTP) protocol fields that to increase a length be 18bit, this field is embedded in original MSTP protocol fields inside, iMST sub-instance under the sign QINQ interface in the MST example, the VLAN ID of the corresponding inner VLAN label of this iMST sub-instance (promptly, the represented spanning-tree instance of nested 802.1Q label number) be appointed as iMSTP ID, other parts of iMSTP ID protocol fields are the same with existing MSTP id field.

Above-mentioned iMST sub-instance at first in the QINQ switching network, increases generation seeds class iMST before being configured, increasing iMST generation tree all is the same with the mode that increases MST generation tree, and iMST and MST, SST, RST after the increase are separate; Then the generation tree example that increases is configured (configuration that the iMST of increase generates the tree example is independent of existing MST spanning-tree instance configuration, but the two but can coexist).

IMST is called " sub-instance ", is expressed as x.y with instance number, and wherein x is an instance number, and y is a sub-instance number.X is illustrated in not to be provided with and generates under the tree example case, the instance number of MST, and it can be corresponding to the set (under the QINQ condition, promptly being positioned at the set of outside VLAN label) of the VLAN of some row; Y is illustrated in and is provided with under the situation that generates the tree example, and iMST sub-instance number is corresponding to the set (under the QINQ condition, promptly being positioned at the set of inner VLAN label) of internal layer private network VLAN.

For example, under the QINQ condition, outside VLAN is designated as VLAN10, inner VLAN is designated as VLAN20, can set MST example 1 corresponding to outside VLAN label VLAN 10, and iMST example 1.1 is corresponding to inner VLAN label VLAN 20, working as iMST so enables, data message carries out when mutual, and the topology environment of being walked is just by the VLAN20 decision of internal layer, and is not outer field VLAN10.Different iMST sub-instances can hang under the same MST example, as shown in Figure 1.

The iSMT sub-instance must depend on the MST example, if do not calculate but know why public network VLAN ID is worth on earth or need not to generate tree according to public network VLAN label at all, can adopt so and MST example 1VLAN ID1-4094 is set (for the QINQ agreement, in the data message of band VLAN label, the VLAN id field that a 12bit length is arranged, this field are used to deposit VLAN ID value, and the value space of this value is 1 to 4094) method, all iMST sub-instance binding MST example 1, i.e. 1.y.

For the two-layer VPN agreement, with VPLS (virtual special local area network) agreement is example, for the support of iMSTP agreement can be provided, when carrying out the iMST configuration, at first should solve iMST for the difficult point in the support of VPLS, the i.e. uncertainty of private network inner VLAN label.The uncertainty of so-called private network vpn label, at be switch (specifically being meant high-end multi-layer switches) with MPLS function.

If will solve above-mentioned difficult point, should obtain the packaged type (encapsulation mode of PE entrance side port has determined the implementation of two-layer VPN label memory) of PE entrance side port so earlier, in the VPLS network, at PE side xconnect interface two kinds of packaged types are arranged: access VLAN and trunk VLAN.

If PE side xconnect interface has been configured to the trunk mode, owing to increased the VPLS VLAN net of the configuration mode of iMST, at VPLS message characteristics, the VLAN label of encapsulation generates tree example coupling in the MPLS label.This mode is similar to the QINQ mode, the iSMT sub-instance that iMSTP is mated PE side xconnect interface trunk encapsulation value is filled into the iMSTP id field in the switch b PDU message, employing is disposed one by one to the P multi-layer switches, before carrying out the MPLS label distribution, just calculate and generate tree example topology, as shown in Figure 2, all the other can be continued to use the QINQ mode and implement.

If PE side xconnect interface configuration is the access mode, for access VLAN, the private network vpn label is can not carry the 802.1Q label, bring difficulty so just for the differentiation private network, and present VPLS vpn label distributes idle, the mode at random of adopting, from the 16-1048575 Random assignment, be difficult to know in advance how VPLS internal layer mark specifically distributes.

In order to address the above problem, carry out the configuration of VCID at PE side xconnect interface, compose to iMSTP ID giving the VCID value that different business distributed in each two-layer VPN, promptly, increase VPLS VCID function under the iMSTP configuration mode, this functional representation private network business is distinguished according to self VCID, iMSTP is with private network VPN VCID value configure iMST sub-instance and be filled into iMSTPID field in the switch b PDU message, and configuration one by one on the P multi-layer switches, calculate and set up new topology with this based on VCID, carrying out the TCP message on this basis shakes hands, set up the MPLS label binding, as shown in Figure 3, all the other can be continued to use the QINQ mode and implement.

In sum, for the two-layer VPN agreement, when generating the calculating of tree example topology, only need to determine the relation one to one of vpn label value and iMSTP ID, if determined the label memory (promptly going into parameter for) of two-layer VPN, then can apply mechanically the settling mode of QINQ label memory (promptly going into parameter for one), this is gone in the parameter substitution topology computational methods, draw and generate tree example topology.

To be the present invention carry out the system construction drawing of functional verification test to IP network equipment to Fig. 5, and two ports of use test instrument link to each other with two user access port of tested equipment respectively, and note is made port one and 2, four equipment under tests of port are formed looped network respectively.

If the iMSTP pattern of described equipment under test adopts the networking of QINQ mode, then concrete testing procedure comprises:

Step 1, all interconnecting interfaces of equipment under test are configured to the QINQ interface, and two equipment under tests that connect tester play PE effect, the message of user side list 802.1Q label are converted into the message of pair 802.1Q labels on the public network;

Step 2 disposes iMSTP on all equipment under tests, at the different VLAN mapping iMSTP sub-instances of user side, it is QINQ that the iMSTP pattern is set, and finishes can observe son after the iMSTP configuration and generate tree (iMSTP) and set up situation;

The user's message that step 3, tester 1 port, 2 ports send out various the 802.1Q label is mutually observed the flow situation of flowing through then on each equipment under test, can attempt the disconnected some of them link that goes, and whether the investigation flow can interrupt.

If the iMSTP pattern of described equipment under test adopts the networking of two-layer VPN pattern, then concrete testing procedure comprises:

Step 1, will with configuration VFI user interface on the direct-connected equipment of tester, and VCID and iMSTP sub-instance shone upon; It is VPLS VCID that the iMSTP pattern is set; Finish and to observe son after the iMSTP configuration and generate tree (iMST) and set up situation;

Step 2 disposes VPLS on the equipment, can observe whether the VPLS label is allocated successfully, whether the pseudo-line of PW set up success;

Step 3, tester port one, port 2 send out various the VFI user's message mutually, then the observation flow situation of flowing through on each equipment under test; Can attempt the disconnected some of them link that goes, investigate flow and whether can interrupt;

Step 4, changing the iMSTP pattern is VPLS VLAN, repeating step 2,3.

The described tested IP network equipment need possess following function, VLAN correlation function, QINQ function, routing function, two-layer VPN function;

Described VLAN correlation function comprises, user vlan isolation features, 802.1Q encapsulation function.Described QINQ function comprises, supports the Layer 2 data of two Q labels to transmit.Described routing function comprises, is used for generating route by configuration, sets up the pseudo-line of L2VPN.Described two-layer VPN function comprises, supports VPLS, VPWS functions such as (Virtual Private Wire Service, the services of virtual private circuit).

Described tester comprises: configuration module: the excuse type according to the service of connection devices disposes accordingly, disposes the flow of system test etc. according to testing requirement; Sending module: the test traffic that configures is sent; Receive module: receive the flow of equipment under test transmission and carry out statistical computation etc.

Above-described embodiment is a more preferably dual mode of the present invention, and any common variation that those skilled in the art carries out in technical scheme scope of the present invention and replacement all should be included in protection scope of the present invention.

Claims

1. the implementation method of a Multiple Spanning Tree Protocol is characterized in that, comprises the steps:

Step 1, need to enter switch through the data message that switch is transmitted, switch is opened and is had the Multiple Spanning Tree Protocol iMSTP that generates the tree example, in protocol massages, increase the iMSTP protocol fields, and according to being provided with of iMSTP protocol fields obtained the setting that iMST generates the tree example, be provided with iMSTP ID in the described iMSTP protocol fields, the value of described iMSTP ID is to be determined by the VLAN networking mode, if adopt the networking of QINQ mode, then iMSTP ID value is the VLAN ID of the inner VLAN label of QINQ; If adopt the networking of two-layer VPN mode, then iMSTP ID value is to VCID value that different business distributed in the trunk value that disposed of two-layer VPN edge interface or the two-layer VPN;

Step 2 is carried out the iMSTP pattern according to the iMSTP ID that is provided with in the described iMSTP protocol fields and is judged, generates tree example topology and calculates;

2. the implementation method of Multiple Spanning Tree Protocol as claimed in claim 1 is characterized in that, in the described step 2, calculates and generates tree example topology, comprises the steps:

Step 2b carries out regional root election;

Step 2c carries out path cost and calculates.

3. the implementation method of Multiple Spanning Tree Protocol as claimed in claim 1 is characterized in that, in the described step 1,

Before carrying out switch unlatching iMSTP Multiple Spanning Tree Protocol, carry out the unlatching of MSTP Multiple Spanning Tree Protocol earlier.

4. the implementation method of Multiple Spanning Tree Protocol as claimed in claim 3 is characterized in that, in the described step 1,

Do not generate the tree example if iMST is set, then carry out MST Multiple Spanning Tree Instance topology and calculate, according to the Multiple Spanning Tree Instance topology, switch is transmitted the dateout message.