External loop detection for an ethernet fabric switch

• US 9,007,958 B2
• Filed: 05/30/2012
• Issued: 04/14/2015
• Est. Priority Date: 06/29/2011
• Status: Expired due to Fees

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Brocade Communications Systems, Inc. (Broadcom, Inc.)
• Inventors: Gupta, Amit, Lei, Tse Yu, Chong, Chi Lung, Raman, Mythilikanth
• Primary Examiner(s): Wu, Jianye
• Application Number:
  US13/484,072
• Publication Number:
  US 20130003601A1
• Time in Patent Office: 1,049 Days
• US Class Current: 370/254
• CPC Class Codes: H04L 12/462 LAN interconnection over a bridge based backbone
• CPC Class Codes: H04L 45/18 Loop-free operations
• CPC Class Codes: H04L 45/586 of virtual routers

Abstract

One embodiment of the present invention provides a switch. The switch includes a local identifier associated with the switch, a receiving interface, a loop detection mechanism, and an interface control mechanism. The receiving interface identifies a loop-detection frame which includes an identifier associated with originating switch of the frame. The loop detection mechanism detects a loop based on a match of the identifier associated with the originating switch and the local identifier. The interface control mechanism is coupled to the loop detection mechanism and precludes, in response to detecting a loop, the receiving interface from forwarding frames corresponding to the loop.

Claims

1. A switch, comprising:

a receiving interface adapted to identify a loop-detection frame which includes a first identifier identifying an originating switch of the loop-detection frame;

a loop-detection module adapted to detect a loop based on a match between the first identifier identifying the originating switch and a fabric identifier identifying an Ethernet fabric switch, wherein the Ethernet fabric switch comprises a number of physical switches and functions as a single switch, wherein the Ethernet fabric switch is distinct from a virtual local area network (VLAN) and can accommodate multiple VLANs, and wherein the switch comprising the receiving interface is a member of the Ethernet fabric switch; and

an interface control module adapted to preclude, in response to detecting the loop, from forwarding frames corresponding to the loop.

2. The switch of claim 1, wherein the detected loop is in a multi-switch link aggregation spanning the switch and the originating switch.

3. The switch of claim 1, wherein the fabric identifier is associated with a respective switch of the Ethernet fabric switch.

4. The switch of claim 1, wherein the loop-detection frame is a layer-2 multicast frame.

5. The switch of claim 1, wherein the interface control module is further adapted to compare a first priority value and a second priority value specified in the loop-detection frame, wherein the first priority value is associated with the receiving interface and the second priority value is associated with an originating interface of the loop-detection frame.

6. The switch of claim 1, wherein the receiving interface is further adapted to identify an originating interface of the loop-detection frame based on a Transparent Interconnection of Lots of Links (TRILL) routing bridge (RBridge) identifier and an interface identifier of the originating interface.

7. The switch of claim 1, wherein the loop-detection frame further includes an identifier of a virtual local area network (VLAN), and

wherein the detected loop is specific to the VLAN.

8. The switch of claim 1, wherein the loop detection module is further adapted to maintain a counter which indicates a number of times the loop-detection frame has been identified;

and

wherein the interface control module is adapted to preclude from forwarding frames corresponding to the loop further in response to a value of the counter exceeding a threshold value.

9. The switch of claim 1, further comprising a logical switch management module adapted to maintain a membership in the Ethernet fabric switch.

10. A computer-executed method, comprising:

identifying, by a receiving interface, a loop-detection frame which includes a first identifier identifying an originating switch of the loop-detection frame;

detecting a loop based on a match between the first identifier identifying the originating switch and a fabric identifying an Ethernet fabric switch, wherein the Ethernet fabric switch comprises a number of physical switches and functions as a single switch, wherein the Ethernet fabric switch is distinct from a virtual local area network (VLAN) and can accommodate multiple VLANs, and wherein a local switch comprising the receiving interface is a member of the Ethernet fabric switch; and

precluding, in response to detecting the loop, from forwarding frames corresponding to the loop.

11. The method of claim 10, wherein the detected loop is in a multi-switch link aggregation spanning the local switch and the originating switch.

12. The method of claim 10, wherein the fabric identifier is associated with a respective switch of the Ethernet fabric switch.

13. The method of claim 10, wherein the loop-detection frame is a layer-2 multicast frame.

14. The method of claim 10, further comprising comparing a first priority value and a second priority value specified in the loop-detection frame, wherein the first priority value is associated with the receiving interface and the second priority value is associated with an originating interface of the loop-detection frame.

15. The method of claim 10, further comprising identifying an originating interface of the loop-detection frame based on a Transparent Interconnection of Lots of Links (TRILL) routing bridge (RBridge) identifier and an interface identifier of the originating interface.

16. The method of claim 10, wherein the loop-detection frame further includes an identifier of a virtual local area network (VLAN), and

wherein the detected loop is specific to the VLAN.

17. The method of claim 10, further comprising maintaining a counter which indicates a number of times the loop-detection frame has been identified;

and

precluding from forwarding frames corresponding to the loop further in response to a value of the counter exceeding a threshold value.

18. The method of claim 10, further comprising maintaining a membership in the Ethernet fabric switch.

19. A non-transitory computer-readable storage medium storing instructions that when executed by a computer cause the computer to perform a method for detecting a loop in a computer network, the method comprising:

identifying, by a receiving interface, a loop-detection frame which includes a first identifier identifying an originating switch of the loop-detection frame;

detecting a loop based on a match between the first identifier identifying the originating switch and a fabric identifier identifying an Ethernet fabric switch, wherein the Ethernet fabric switch comprises a number of physical switches and functions as a single switch, wherein the Ethernet fabric switch is distinct from a virtual local area network (VLAN) and can accommodate multiple VLANs, and wherein a local switch comprising the receiving interface is a member of the Ethernet fabric switch; and

precluding, in response to detecting the loop, from forwarding frames corresponding to the loop.

20. The storage medium of claim 19, wherein the detected loop is in a multi-switch link aggregation spanning the local switch and the originating switch.

21. The storage medium of claim 19, wherein the fabric is associated with a respective switch of the Ethernet fabric switch.

22. The storage medium of claim 19, wherein the loop-detection frame is a layer-2 multicast frame.

23. The storage medium of claim 19, further comprising comparing a first priority value and a second priority value specified in the loop-detection frame, wherein the first priority value is associated with the receiving interface and the second priority value is associated with an originating interface of the loop-detection frame.

24. The storage medium of claim 19, further comprising identifying an originating interface of the loop-detection frame based on a Transparent Interconnection of Lots of Links (TRILL) routing bridge (RBridge) identifier and an interface identifier of the originating interface.

25. The storage medium of claim 19, wherein the loop-detection frame further includes an identifier of a virtual local area network (VLAN), and

wherein the detected loop is specific to the VLAN.

26. The storage medium of claim 19, further comprising maintaining a counter which indicates a number of times the loop-detection frame has been identified;

and

precluding from forwarding frames corresponding to the loop further in response to a value of the counter exceeding a threshold value.

27. The storage medium of claim 19, further comprising maintaining a membership in the Ethernet fabric switch.