CN100454858C

CN100454858C - A method for implementing synchronization of border port information of multiple spanning tree areas

Info

Publication number: CN100454858C
Application number: CNB03104672XA
Authority: CN
Inventors: 陈锋; 汪勇; 陈刚; 苏兴山
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2003-02-19
Filing date: 2003-02-19
Publication date: 2009-01-21
Anticipated expiration: 2023-02-19
Also published as: CN1523821A

Abstract

The present invention relates to a method for implementing the synchronization of the border port information of multiple spanning tree areas, which comprises the steps that whether the related attribute of ports is changed according to rules is judged after every CIST port role selection, if true, a corresponding role selection process is triggered. The present invention can well solve protocol process mistakes when the information of boundary ports changes, and simultaneously has little influence on the processing load of an exchanger since the present invention changes little basic functions of the protocol.

Description

A kind of method that realizes the boundary port information synchronization of Multiple Spanning Tree Regions

Technical field

The present invention relates to the communications field, relate in particular to a kind of implementation method of the boundary port information synchronization at Multiple Spanning Tree Regions.

Technical background

IEEE802.1d and IEEE80.1w have provided the solution of avoiding data loopback and realize the redundant link backup in simple switched network; In order to adapt to the large-scale complicated switching network of multi-VLAN (Virtual Local Area Network VLAN), IEEE802.1s Draftl4 draft has further proposed Multiple Spanning Tree Protocol, i.e. MSTP (Multiple Spanning Tree Protocol).IEEE802.1s is divided into different Multiple Spanning Tree (MST) region with one to a plurality of switching equipment, in a territory, safeguard MSTI (many spanning-tree instances of Multiple Spanning TreeInstance), allow the data message of different VLAN to transmit according to path separately, between all territories, then be connected in series, to guarantee the connectedness of the whole network by CST (Common Spanning Common Spanning Tree).This shows: the maximum feature of IEEE802.1S is exactly that the diversity of spanning-tree instance and complicated Multiple Spanning Tree (MST) region are divided.

But, when the boundary port information of Multiple Spanning Tree (MST) region changes, if trigger mechanism is imperfect between the territory, will material impact take place to the migration of the protocol state machine in the territory, exist many here because the serious problems that information inconsistency causes.As shown in Figure 1:

In Fig. 1, when supposing that switch A (Switch A) and switch b (Switch B) belong to two Multiple Spanning Tree (MST) region respectively, and Switch A belongs to the territory, upstream.Originally a port is the root port on the CIST, and b is the optional port on the CIST, has revised the path cost of port a and b as SwitchB, perhaps revise the speed of port, may make that then the role of a and b switches on CIST, a becomes the optional port on the CIST, and b becomes the root port on the CIST.But since territory internal state machine can processing domain outer protocol information, so this variation can not be transmitted to the MSTI in the SwitchB territory, thereby make MSTI think that port a remains the master port in territory, a remains on forwarding state with port, so and between the territory only by Common Spanning Tree communicate machine-processed inconsistent, cause the communication of whole network undesired.

In addition, when supposing that Switch A and Switch B belong to same Multiple Spanning Tree (MST) region, and Switch A is positioned at the upstream.If at this moment revise the domain name of Switch A, make Switch A different with Switch B domain name, at this moment because the handling problem of agreement self, Switch B is not any role to CIST and calculates, also MSTI not being any role calculates, and in fact port a and port b should have one to become the master port of all MSTI and enter forwarding state, and another port becomes the optional port of all MSTI and enters blocked state.We will see, and will be under the prior protocols framework, consequently incorrect.

In existing technology, proposed among the IEEE802.1s to realize the protocol of multiple spanning tree in the switching equipment, and realized fast transferring under certain conditions.But because the mistake of protocol, when boundary port generation domain information in territory changes, the synchronism that can't guarantee information exchanges, thus cause serious problems.

Summary of the invention

Purpose of the present invention just provides a kind of boundary port information synchronization implementation method of Multiple Spanning Tree Regions, when changing to solve territory boundary port information, to the protocol state machine in the territory owing to the problem that exists information inconsistency to cause.

A kind of method that realizes the boundary port information synchronization of Multiple Spanning Tree Regions, this method comprises:

When each public and Internal Spanning Tree port role are selected, when perhaps receiving the Spanning-Tree Protocol message, judge whether the port attribute on border, territory changes, if change, then trigger corresponding role's selection course; Wherein,

When each public and Internal Spanning Tree port role are selected, the described port attribute of judging the border, territory whether change for: whether public the and Internal Spanning Tree information that keeps on the boundary port of territory changes for root port from the public of overseas and port and Internal Spanning Tree role, or whether public the and Internal Spanning Tree information that keeps on the boundary port of territory changes for optional port from the public of overseas and port and Internal Spanning Tree role;

When receiving the Spanning-Tree Protocol message, the described port attribute of judging the border, territory whether change for: whether the source, territory of the message that this is received and the territory source-information of a last message change.

Whether the source, territory of the described message that this is received and the territory source-information of a last message change and are meant a protocol massages from the territory, but current message is from overseas.

Whether the source, territory of the described message that this is received and the territory source-information of a last message change and are meant a protocol massages from overseas, but current message is from the territory.

Owing to adopted multiple spanning tree boundary port information synchronization implementation method of the present invention, the protocol processes mistake the when information that can solve the territory boundary port changes.Simultaneously, the present invention changes minimum to the basic function of agreement, thereby very little to the load influence of switch processes.

Description of drawings

Fig. 1 is in the prior art, the schematic diagram that territory boundary port information changes;

Fig. 2 adopts a port role selection mode machine schematic diagram of the present invention;

Fig. 3 adopts port information state machine diagram of the present invention.

Embodiment

Below in conjunction with Figure of description the specific embodiment of the present invention is described.

As shown in Figure 2, whether core concept of the present invention is when each port role is selected, perhaps when receiving the Spanning-Tree Protocol message, change according to the association attributes of certain rule judgment territory boundary port, if change, then to should the corresponding role's selection course of change triggers.

Here, judge that the content that territory boundary port association attributes changes mainly contains as described below:

1, when each CIST port role was selected, described judgement content was:

Whether the CIST information that keeps on the boundary port of territory changes for this condition of root port from the CIST role of overseas and port; (set up promptly, be false afterwards if above-mentioned judgement content before and after each CIST port role is selected variation has taken place; Be false before perhaps, set up afterwards), then trigger role's selection course of MSTI (Multiple Spanning Tree Instance Multiple Spanning Tree Instance).In fact here be the judgement of a NAND true value in logic, when the NAND condition produces, then cause above-mentioned role transforming.

2, when each CIST port role was selected, described judgement content was:

Whether the CIST information that keeps on the boundary port of territory changes for this condition of optional port from the CIST role of overseas and port; (set up promptly, be false afterwards if above-mentioned judgement content before and after each CIST port role is selected variation has taken place; Be false before perhaps, set up afterwards), then trigger role's selection course of MSTI (Multiple Spanning Tree Instance Multiple Spanning Tree Instance).

3, when receiving the Spanning-Tree Protocol message, described judgement content is:

The source, territory of the message that this is received and the territory source-information of a last message change; If change, then trigger CIST role's selection course.

From overseas, this message is from the territory such as a last message, and perhaps in contrast, a last message is from the territory, and this message then triggers CIST role's selection course from overseas.

By such scheme, can coordinate the consistency of port information.

Among the present invention, can be illustrated like this:

At first the attribute to the territory boundary port defines

Whether the CIST information that keeps on the definition port attribute A=port is from (TRUE/FALSE) in the territory;

Whether the CIST role of definition port attribute B=port is root port (TRUE/FALSE);

Whether the CIST role of definition port attribute C=port is optional port (TRUE/FALSE);

Whether the message that definition port attribute D=the port is received for the last time is from (TRUE/FALSE) in the territory.

Definition port attribute E=A ﹠amp; ﹠amp; B

Definition port attribute F=A ﹠amp; ﹠amp; C

Definition rule then:

1, after carrying out the selection of CIST port role, judges whether the attribute E of each territory boundary port and F change at every turn;

2, when receiving message, judge whether variation has taken place the port attribute D receive message (that is: a last protocol massages is from the territory, but current message is from overseas at every turn; Perhaps go up a protocol massages from overseas, but current protocol massages is from the territory);

If one of 3 attribute E or attribute F change, just trigger role's selection course of MSTI example; If port attribute D changes, from the territory, but current message is perhaps gone up a protocol massages from overseas from overseas such as a protocol massages, but current message in case produce this variation, just triggers CIST role's selection course from the territory.

Thus, can guarantee the consistency of port information.

See the example of a specific design below:

Shown in Fig. 2 and 3, be to adopt the synchronization mechanism of territory boundary port information to solve the state machine diagram of the embodiment of this problem.Wherein, underscore partly is a change point in the state machine.

We create following two attributes at each port:

BoundaryRoot: when the port role of this port on CIST is root port, and the port priority information on the CIST is from overseas (being infosIs==RECEIVED and infoInternal==FALSE), and then BoundaryRoot is TRUE; Otherwise be FALSE.

BoundaryAlter: when the port role of this port on CIST is optional port, and the port priority information on the CIST is from overseas (being infosIs==RECEIVED and infoInternal==FALSE), and then BoundaryAlter is TRUE; Otherwise be FALSE.

When the initialization of the INIT_BRIDGE of PRS state machine bridge, add following processing links:

ClearBoundaryRootOrAlter (): the BoundaryRoot and the BoundaryAlter of all of the port are resetted.

In the RECEIVE of PRS state machine state, add following processing links:

DealBoundaryRootOrAlterChange ():, recomputate new BoundaryRoot of each port and BoundaryAlter according to the definition of this patent to BoundaryRoot and BoundaryAlter.If have the BoundaryRoot of any one port or the value of BoundaryAlter to change, the PRS state machine that then this triggering is comprised all MSTI examples of this port calculates, thereby revises role and the state of MSTI.

In addition, carry out new processing as shown in Figure 3, comprising at the REPEATED_DESIGNATED of PIM state machine state:

If infoInternal is not equal to rcvdInternal, then show whether change from overseas information, at this moment,, then trigger the PRS state machine of CIST if this state machine operates in the CIST example environment.BoundaryRootOrAlter mechanism by this patent guarantees that further MSTI can be recomputated then.

The present invention is by above this scheme, the protocol processes mistake the when information that can well solve the territory boundary port changes, simultaneously, and because that the present invention changes the basic function of agreement is minimum, thus very little to the load influence of switch processes.

The above; only for the preferable embodiment of the present invention, but protection scope of the present invention is not limited thereto, and anyly is familiar with those skilled in the art in the technical scope that the present invention discloses; the variation that can expect easily or replacement all should be encompassed within protection scope of the present invention.Therefore, protection scope of the present invention should be as the criterion with the protection range of claims.

Claims

1, a kind of method that realizes the boundary port information synchronization of Multiple Spanning Tree Regions is characterized in that this method comprises:

2, the method for the boundary port information synchronization of realization Multiple Spanning Tree Regions as claimed in claim 1, it is characterized in that, whether the source, territory of the described message that this is received and the territory source-information of a last message change and are meant a protocol massages from the territory, but current message is from overseas.

3, the method for the boundary port information synchronization of realization Multiple Spanning Tree Regions as claimed in claim 1, it is characterized in that, whether the source, territory of the described message that this is received and the territory source-information of a last message change and are meant a protocol massages from overseas, but current message is from the territory.