Spanning-tree based loop detection for an ethernet fabric switch

• US 8,948,056 B2
• Filed: 06/26/2012
• Issued: 02/03/2015
• Est. Priority Date: 06/28/2011
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Brocade Communications Systems, Inc. (Broadcom, Inc.)
• Inventors: Lei, Tse Yu, Song, Ning, Venkatesh, Vardarajan, Raman, Mythilikanth
• Primary Examiner(s): Lee, Andrew
• Application Number:
  US13/533,843
• Publication Number:
  US 20130003608A1
• Time in Patent Office: 952 Days
• Field of Search: 370/256, 370/392, 370/393, 370/400
• US Class Current: 370/256
• CPC Class Codes: H04L 12/462 LAN interconnection over a bridge based backbone
• CPC Class Codes: H04L 45/66 Layer 2 routing, e.g. in Ethernet based MAN's
• CPC Class Codes: H04L 49/351 for local area network [LAN], e.g. Ethernet switches
• CPC Class Codes: H04L 49/354 for supporting virtual local area networks [VLAN]

Abstract

One embodiment of the present invention provides a switch. The switch includes a local database, a packet processor, a data management module, and a tree construction module. The packet processor extracts spanning tree information associated with a remote switch. The data management module stores the extracted spanning tree information in the local database. The tree construction module assigns an interface state associated with a spanning tree to a local interface based on the extracted spanning tree information.

Claims

1. A switch, comprising:

a packet processor operable to extract spanning tree information associated with a remote switch;

a data management module operable to store the extracted spanning tree information in a local database; and

a tree construction module operable to

assign an interface state associated with a spanning tree to a local interface based on the extracted spanning tree information; and

preclude the local interface from forwarding frames based on the assigned interface state.

2. The switch of claim 1, wherein the spanning tree information is associated with one or more of the following protocols:

Spanning Tree Protocol (STP);

Rapid Spanning Tree Protocol (RSTP); and

Multiple Spanning Tree Protocol (MSTP).

3. The switch of claim 1, wherein the packet processor is further operable to extract updated spanning tree information associated with the remote switch;

wherein the data management module is further operable to determine difference between the spanning tree information in the local database and the updated spanning tree information; and

wherein the packet processor is further operable to construct a frame containing the information difference for the remote switch.

4. The switch of claim 1, wherein the packet processor is further operable to extract spanning tree state synchronization information associated with the remote switch from a received frame;

and

wherein the tree construction module assigns the interface state based on the spanning tree state synchronization information.

5. The switch of claim 1, wherein the tree construction module is further operable to identify the local interface based on an interface identifier, wherein the interface identifier is unique in the switch and the remote switch.

6. The switch of claim 1, wherein the switch and the remote switch are members of an Ethernet fabric switch;

and

wherein the switch and the remote switch are associated with an identifier of the Ethernet fabric switch.

7. The switch of claim 1, wherein the tree construction module is further operable to assign the interface state on a per virtual local area network (VLAN) basis.

8. The switch of claim 7, wherein the tree construction module is further operable to consolidate interface states associated with a plurality of VLANs into a single interface state.

9. The switch of claim 1, wherein the packet processor is further operable to extract frames encapsulated in a Transparent Interconnection of Lots of Links (TRILL) header.

10. A computer-executable method, comprising:

extracting, by a computing device, spanning tree information associated with a remote switch;

storing the extracted spanning tree information in a local database;

assigning an interface state associated with a spanning tree to a local interface based on the extracted spanning tree information; and

precluding the local interface from forwarding frames based on the assigned interface state.

11. The method of claim 10, wherein the spanning tree information is associated with one or more of the following protocols:

Spanning Tree Protocol (STP);

Rapid Spanning Tree Protocol (RSTP); and

Multiple Spanning Tree Protocol (MSTP).

12. The method of claim 10, further comprising:

extracting updated spanning tree information associated with the remote switch;

determining difference between the spanning tree information in the local database and the updated spanning tree information; and

constructing a frame containing the information difference for the remote switch.

13. The method of claim 10, further comprising:

extracting spanning tree state synchronization information associated with the remote switch from a received frame; and

assigning the interface state based on the spanning tree state synchronization information.

14. The method of claim 10, further comprising identifying the local interface based on an interface identifier, wherein the interface identifier is unique in the switch and the remote switch.

15. The method of claim 10, wherein the switch and the remote switch are members of an Ethernet fabric switch;

and

wherein the switch and the remote switch are associated with an identifier of the Ethernet fabric switch.

16. The method of claim 10, further comprising assigning the interface state on a per virtual local area network (VLAN) basis.

17. The method of claim 16, further comprising consolidating interface states associated with a plurality of VLANs into a single interface state.

18. The method of claim 16, further comprising extracting frames encapsulated in a Transparent Interconnection of Lots of Links (TRILL) header.

19. A computing system, comprising:

a processor; and

a non-transitory computer-readable storage medium storing instructions that when executed by the processor cause the computing system to perform a method for creating a spanning tree in a computer network, the method comprising;

extracting spanning tree information associated with a remote computing system;

storing the extracted spanning tree information in a local database;

assigning an interface state associated with a spanning tree to a local interface based on the extracted spanning tree information; and

precluding the local interface from forwarding frames based on the assigned interface state.

20. The switch of claim 19, wherein the computing system and the remote computing system are members of an Ethernet fabric switch;

and

wherein the computing system and the remote computing system are associated with an identifier of the Ethernet fabric switch.

21. A switch, comprising:

a packet processor operable to extract spanning tree information associated with a remote switch;

a data management module operable to store the extracted spanning tree information in a local database; and

a tree construction module operable to

assign an interface state associated with a spanning tree to a local interface based on the extracted spanning tree information; and

identify the local interface based on an interface identifier, wherein the interface identifier is unique in the switch and the remote switch.

22. The switch of claim 21, wherein the packet processor is further configurable to extract updated spanning tree information associated with the remote switch;

wherein the data management module is further configurable to determine difference between the spanning tree information in the local database and the updated spanning tree information; and

wherein the packet processor is further configurable to construct a frame containing the information difference for the remote switch.

23. The switch of claim 21, wherein the packet processor is further configurable to extract spanning tree state synchronization information associated with the remote switch from a received frame;

and

wherein the tree construction module assigns the interface state based on the spanning tree state synchronization information.

24. A switch, comprising:

a packet processor operable to extract spanning tree information associated with a remote switch; and

a tree construction module operable to assign an interface state associated with a spanning tree to a local interface based on the extracted spanning tree information;

wherein the switch and the remote switch are members of an Ethernet fabric switch; and

wherein the switch and the remote switch are associated with an identifier of the Ethernet fabric switch.

25. A switch, comprising:

a packet processor operable to extract spanning tree information associated with a remote switch;

a tree construction module operable to

assign an interface state associated with a spanning tree to a local interface based on the extracted spanning tree information; and

assign the interface state on a per virtual local area network (VLAN) basis.

26. The switch of claim 25, wherein the tree construction module is further operable to consolidate interface states associated with a plurality of VLANs into a single interface state.