Multi-stage switch fabric fault detection and handling

• US 10,382,254 B2
• Filed: 01/08/2018
• Issued: 08/13/2019
• Est. Priority Date: 02/16/2015
• Status: Active Grant

• Current Assignee: Juniper Networks Incorporated
• Original Assignee: Juniper Networks Incorporated
• Inventors: Yadav, Alam, Golash, Mukul
• Primary Examiner(s): Acolatse, Kodzovi
• Application Number:
  US15/864,881
• Publication Number:
  US 20180131561A1
• Time in Patent Office: 582 Days
• Field of Search: None
• CPC Class Codes: H04L 41/0654 using network fault recovery ring fault isolation or reconfiguration in loop networks without recovery actions by a network management system H04L12/437
• CPC Class Codes: H04L 41/08 Configuration management of networks or network elements address allocation H04L61/50
• CPC Class Codes: H04L 43/0811 by checking connectivity
• CPC Class Codes: H04L 45/28 using route fault recovery
• CPC Class Codes: H04L 49/00 Packet switching elements
• CPC Class Codes: H04L 49/101 using crossbar or matrix
• CPC Class Codes: H04L 49/1523 Parallel switch fabric planes
• CPC Class Codes: H04L 49/40 Constructional details, e.g. power supply, mechanical construction or backplane
• CPC Class Codes: H04L 49/555 Error detection
• CPC Class Codes: H04L 49/557 Error correction, e.g. fault recovery or fault tolerance
• CPC Class Codes: H04Q 11/04 for time-division multiplexing H04Q11/0001 takes precedence

Abstract

In some examples, a switching system includes a plurality of fabric endpoints and a multi-stage switching fabric having a plurality of fabric planes each having a plurality of stages to switch data units between any of the plurality of fabric endpoints. A fabric endpoint of the fabric endpoints is configured to send, to a switch of a first one of the stages and within a first fabric plane of the plurality of fabric planes, a self-ping message destined for the fabric endpoint. The fabric endpoint is configured to send, in response to determining the fabric endpoint has not received the self-ping message after a predetermined time, an indication of a connectivity fault for the first fabric plane.

Claims

1. A method of verifying fabric connectivity with a multi-stage switch fabric having a plurality of fabric planes each having a plurality of stages to switch data units between any of a plurality of fabric endpoints, the method comprising:

receiving, by a first-stage switch of a first fabric plane of the multi-stage switch fabric, a first fault data unit that includes an indication of a connectivity fault;

after receiving the first fault data unit, by the first-stage switch, waiting a predefined time;

receiving, by the first-stage switch, a second fault data unit that includes the indication of the connectivity fault; and

sending, in response to expiry of the predefined time and after receiving the second fault data unit, by the first-stage switch to a final-stage switch of the first fabric plane and after consolidating the first fault data unit and the second fault data unit, a fault notification data unit that includes the indication of the connectivity fault.

2. The method of claim 1,

wherein receiving the first fault data unit comprises receiving, by the first-stage switch, the first fault data unit from a first fabric endpoint of the plurality of fabric endpoints, and

wherein receiving the second fault data unit comprises receiving, by the first-stage switch, the second fault data unit from a second fabric endpoint of the plurality of fabric endpoints.

3. The method of claim 1, wherein the plurality of fabric endpoints comprises a plurality of forwarding components interconnected within a network router by the multi-stage switch fabric.

4. The method of claim 1, wherein the plurality of fabric endpoints comprises a plurality of edge devices interconnected within a data center by the multi-stage switch fabric.

5. The method of claim 1, wherein the predefined time is 1 millisecond.

6. The method of claim 1, wherein the indication of the connectivity fault identifies the first fabric plane.

7. The method of claim 1,

wherein the final-stage switch comprises a first final-stage switch, and

wherein the fault notification data unit comprises a first fault notification data unit, the method further comprising:

sending, by the first-stage switch to a second final-stage switch of the first fabric plane and after consolidating the first fault data unit and the second fault data unit, a second fault notification data unit that includes the indication of the connectivity fault.

8. The method of claim 1, further comprising:

sending, by the final-stage switch in response to receiving the fault notification data unit from the first-stage switch, respective fault notification data units to fabric endpoints of the plurality of fabric endpoints that are coupled to the final-stage switch.

9. A method of verifying fabric connectivity with a multi-stage switch fabric having a plurality of fabric planes each having a plurality of stages to switch data units between any of a plurality of fabric endpoints, the method comprising:

sending, by a first fabric endpoint of the plurality of fabric endpoints in response to the first fabric endpoint detecting a first connectivity fault for the first fabric endpoint with the switch fabric, a first fault data unit that includes an indication of the first connectivity fault to a first-stage switch of a first fabric plane of the multi-stage switch fabric;

receiving, by the first-stage switch, the first fault data unit;

sending, by a second fabric endpoint of the plurality of fabric endpoints in response to the second fabric endpoint detecting a second connectivity fault for the second fabric endpoint with the switch fabric, a second fault data unit that includes an indication of the second connectivity fault to the first-stage switch;

receiving, by the first-stage switch, the second fault data unit; and

sending, by the first-stage switch to a final-stage switch of the first fabric plane and after consolidating the first fault data unit and the second fault data unit, a fault notification data unit that includes an indication of the first connectivity fault and the second connectivity fault.

10. The method of claim 9, wherein the indication of the first connectivity fault identifies the first fabric plane.

11. A switching system comprising:

a plurality of fabric endpoints;

a multi-stage switching fabric having a plurality of fabric planes each having a plurality of stages to switch data units between any of the plurality of fabric endpoints,

wherein a first-stage switch of a first fabric plane of the multi-stage switch fabric is configured to receive a first fault data unit that includes an indication of a connectivity fault,

wherein the first-stage switch is configured to, after receiving the first fault data unit, wait a pre-defined time,

wherein the first-stage switch is configured to receive a second fault data unit that includes the indication of the connectivity fault, and

wherein the first-stage switch is configured send, in response to expiry of the predefined time and after receiving the second fault data unit, to a final-stage switch of the first fabric plane and after consolidating the first fault data unit and the second fault data unit, a fault notification data unit that includes the indication of the connectivity fault.

12. The switching system of claim 11,

wherein the first-stage switch is configured to receive the first fault data unit from a first fabric endpoint of the plurality of fabric endpoints, and

wherein the first-stage switch is configured to receive the second fault data unit from a second fabric endpoint of the plurality of fabric endpoints.

13. The switching system of claim 11, wherein the plurality of fabric endpoints comprises a plurality of forwarding components interconnected within a network router by the multi-stage switch fabric.

14. The switching system of claim 11, wherein the plurality of fabric endpoints comprises a plurality of edge devices interconnected within a data center by the multi-stage switch fabric.

15. The switching system of claim 11, wherein the predefined time is 1 millisecond.

16. The switching system of claim 11, wherein the indication of the connectivity fault identifies the first fabric plane.

17. The switching system of claim 11,

wherein the final-stage switch comprises a first final-stage switch, and

wherein the fault notification data unit comprises a first fault notification data unit,

wherein the first-stage switch is configured to send, to a second final-stage switch of the first fabric plane and after consolidating the first fault data unit and the second fault data unit, a second fault notification data unit that includes the indication of the connectivity fault.

18. The switching system of claim 11,

wherein the final-stage switch is configured to send, in response to receiving the fault notification data unit from the first-stage switch, respective fault notification data units to fabric endpoints of the plurality of fabric endpoints that are coupled to the final-stage switch.

19. A switching system comprising:

a plurality of fabric endpoints; and

a multi-stage switching fabric having a plurality of fabric planes each having a plurality of stages to switch data units between any of the plurality of fabric endpoints,

wherein a first fabric endpoint of the plurality of fabric endpoints is configured to, in response to the first fabric endpoint detecting a first connectivity fault for the first fabric endpoint with the switch fabric, send a first fault data unit that includes an indication of the first connectivity fault to a first-stage switch of a first fabric plane of the multi-stage switch fabric,

wherein the first-stage switch is configured to receive the first fault data unit,

wherein a second fabric endpoint of the plurality of fabric endpoints is configured to, in response to the second fabric endpoint detecting a second connectivity fault for the second fabric endpoint with the switch fabric, send a second fault data unit that includes an indication of the second connectivity fault to the first-stage switch,

wherein the first-stage switch is configured to receive the second fault data unit, and

wherein the first-stage switch is configured send, to a final-stage switch of the first fabric plane and after consolidating the first fault data unit and the second fault data unit, a fault notification data unit that includes an indication of the first connectivity fault and the second connectivity fault.

20. The switching system of claim 19, wherein the indication of the first connectivity fault identifies the first fabric plane.

21. A computer-readable storage medium, the computer-readable storage medium comprising instructions for causing at least one programmable processor of a multi-stage switch fabric, having a plurality of fabric planes each having a plurality of stages to switch data units between any of a plurality of fabric endpoints, to:

receive, by a first-stage switch of a first fabric plane of the multi-stage switch fabric, a first fault data unit that includes an indication of a connectivity fault;

after receiving the first fault data unit, by the first-stage switch, wait a predefined time;

receive, by the first-stage switch, a second fault data unit that includes the indication of the connectivity fault; and

send, in response to expiry of the predefined time and after receiving the second fault data unit, by the first-stage switch to a final-stage switch of the first fabric plane and after consolidating the first fault data unit and the second fault data unit, a fault notification data unit that includes the indication of the connectivity fault.