Compatible methods and systems for multiple spanning tree protocols

• US 20070121672A1
• Filed: 01/25/2006
• Published: 05/31/2007
• Est. Priority Date: 11/29/2005
• Status: Active Grant

• Current Assignee: Institute For Information Industry
• Original Assignee: Institute For Information Industry
• Inventors: Kang, Chi-Cheng
• Granted Patent: US 7,633,890 B2
• Time in Patent Office: Days
• US Class Current: 370/466
• CPC Class Codes: H04L 12/4625 Single bridge functionality, e.g. connection of two networks over a single bridge
• CPC Class Codes: H04L 12/66 Arrangements for connecting between networks having differing types of switching systems, e.g. gateways

Abstract

A compatible method for multiple spanning tree protocols. A verification module is provided between a standard multiple spanning tree (MST) module and a LLC layer and Ethernet driver module. The verification module executes a reception verification procedure and a transmission verification procedure. The verification module, the standard MST module, and the LLC layer and Ethernet driver module are established in a switch. A bridge protocol data unit (BPDU) is received by the verification module. If the BPDU comes from the LLC layer and Ethernet driver module, the verification procedure is executed for the received BPDU. If the BPDU comes from the standard MST module, the transmission verification procedure is executed for the BPDU.

Claims

1. A compatible method for multiple spanning tree protocols, comprising:

providing a verification module between a standard multiple spanning tree (MST) module and a LLC layer and Ethernet driver module for executing a reception verification procedure and a transmission verification procedure, wherein the verification module, the standard MST module, and the LLC layer and Ethernet driver module are established in a switch;

receiving a bridge protocol data unit (BPDU); and

executing the reception verification procedure when the BPDU comes from the LLC layer and Ethernet driver module and executing the transmission verification procedure when the BPDU comes from the standard MST module.

2. The compatible method for multiple spanning tree protocols as claimed in claim 1, wherein the reception verification procedure comprises:

determining a class of the BPDU, wherein the classes comprise a first MST protocol and a second MST protocol;

determining if a communication port of the switch is recorded as the second MST protocol when the BPDU conforms to the first MST protocol;

setting the communication port conforming to the first MST protocol when the communication port is recorded as the second MST protocol;

identifying if the BPDU is the same as a MST protocol region configuration of the switch when the BPDU conforms to the second MST protocol;

setting the communication port conforming to the second MST protocol when the BPDU is the same as the MST protocol region configuration of the switch; and

packaging the BPDU conforming to the first MST protocol when the BPDU conforms to the second MST protocol.

3. The compatible method for multiple spanning tree protocols as claimed in claim 2, wherein determination of the class of the BPDU is accomplished by at least one step, comprising:

determining if a value of a Version 3 Length field of the BPDU is zero;

determining if a value of a MST Extended Information field of the BPDU is larger than or equal to 64;

determining if a total length of the BPDU minus 38 is larger than or equal to the value of the MST Extended Information field of the BPDU;

determining if the total length of the BPDU minus 103 is a multiple of 26; and

determining if the value of the MST Extended Information field of the BPDU minus 64 is a multiple of 26.

4. The compatible method for multiple spanning tree protocols as claimed in claim 2, further clearing identity information after setting the communication port conforming to the second MST protocol, wherein the identity information indicates information related to the first MST protocol transmission data and is recorded in the communication port of the BPDU.

5. The compatible method for multiple spanning tree protocols as claimed in claim 2, further recording identity information before setting the communication port conforming to the second MST protocol, wherein the identity information indicates information related to the first MST protocol transmission data and is recorded in the communication port of the BPDU.

6. The compatible method for multiple spanning tree protocols as claimed in claim 2, wherein identification of the sameness of the BPDU and the MST protocol region configuration of the switch is accomplished by at least one step, comprising:

identifying if a Configuration Name field of the BPDU is the same as a configuration name field of the switch; and

identifying if a MSTI Message amount of the BPDU is the same as a valid spanning tree amount of the switch.

7. The compatible method for multiple spanning tree protocols as claimed in claim 2, wherein the first MST protocol is IEEE standard MST protocol, a MST protocol of the switch.

8. The compatible method for multiple spanning tree protocols as claimed in claim 2, wherein the second MST protocol is Cisco standard MST protocol, a MST protocol compatible to the switch.

9. The compatible method for multiple spanning tree protocols as claimed in claim 1, wherein the transmission verification procedure comprises:

determining if a communication port of the switch conforms to the second MST protocol; and

packaging the BPDU conforming to the second MST protocol when the communication port conforming to the second MST protocol.

17. The compatible system for multiple spanning tree protocols as claimed in claim 1, wherein the second MST protocol is Cisco standard MST protocol, a MST protocol compatible to the switch.

10. A compatible system for multiple spanning tree protocols, comprising:

a verification module, established between a standard multiple spanning tree (MST) module and a LLC layer and Ethernet driver module for executing a reception verification procedure and a transmission verification procedure, wherein the verification module, the standard MST module, and the LLC layer and Ethernet driver module are established in a switch;

wherein the verification module further comprises;

a protocol identification module, identifying a class of a bridge protocol data unit (BPDU) and providing MST protocol records for a communication port;

a region verification module, verifying a region for a BPDU and providing identity information records of a communication port; and

a package conversion module, packaging BPDUs in various formats;

wherein when the verification module executes the reception verification procedure and the transmission verification procedure, required functions and parameters are provided by the protocol identification module, the region verification module, and the package conversion module.

11. The compatible system for multiple spanning tree protocols as claimed in claim 10, wherein the verification module executes the reception verification procedure by:

determining a class of the BPDU, wherein the classes comprise a first MST protocol and a second MST protocol;

determining if a communication port of the switch is recorded as the second MST protocol when the BPDU conforms to the first MST protocol;

setting the communication port conforming to the first MST protocol when the communication port is recorded as the second MST protocol;

identifying if the BPDU is the same as a MST protocol region configuration of the switch when the BPDU conforms to the second MST protocol;

setting the communication port conforming to the second MST protocol when the BPDU is the same as the MST protocol region configuration of the switch; and

packaging the BPDU conforming to the first MST protocol when the BPDU conforms to the second MST protocol.

12. The compatible system for multiple spanning tree protocols as claimed in claim 11, wherein determination of the class of the BPDU is provided by the protocol identification module and accomplished by at least one step, comprising:

determining if a value of a Version 3 Length field of the BPDU is zero;

determining if a value of a MST Extended Information field of the BPDU is larger than or equal to 64;

determining if a total length of the BPDU minus 38 is larger than or equal to the value of the MST Extended Information field of the BPDU;

determining if the total length of the BPDU minus 103 is a multiple of 26; and

determining if the value of the MST Extended Information field of the BPDU minus 64 is a multiple of 26.

13. The compatible system for multiple spanning tree protocols as claimed in claim 11, wherein the protocol identification module further clears identity information after setting the communication port conforming to the second MST protocol, and the identity information indicates information related to the first MST protocol transmission data and is recorded in a communication port of the BPDU.

14. The compatible system for multiple spanning tree protocols as claimed in claim 11, wherein the protocol identification module further records identity information before setting the communication port conforming to the second MST protocol, and the identity information indicates information related to the first MST protocol transmission data and is recorded in a communication port of the BPDU.

15. The compatible system for multiple spanning tree protocols as claimed in claim 11, wherein identification of the sameness of the BPDU and the MST protocol region configuration of the switch is provided by the region verification module and accomplished by at least one step, comprising:

identifying if a Configuration Name field of the BPDU is the same as a configuration name field of the switch; and

identifying if a MSTI Message amount of the BPDU is the same as a valid spanning tree amount of the switch.

16. The compatible system for multiple spanning tree protocols as claimed in claim 11, wherein the first MST protocol is IEEE standard MST protocol, a MST protocol of the switch.

18. The compatible system for multiple spanning tree protocols as claimed in claim 10, wherein the verification module executes the transmission verification module by:

determining if a communication port of the switch conforms to the second MST protocol; and

packaging the BPDU conforming to the second MST protocol when the communication port conforming to the second MST protocol.

19. The compatible system for multiple spanning tree protocols as claimed in claim 10, wherein the compatible system for multiple spanning tree protocols is implemented as a switch.