Multi-stage switch fabric fault detection and handling

A method of signaling a fabric fault for 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 plurality of fabric planes, an indication of a fabric fault for a second fabric plane of the plurality of fabric planes, the first fabric plane different than the second fabric plane;
• sending, by the first-stage switch to a first final-stage switch of the first fabric plane, a first fault notification data unit that includes the indication of the fabric fault;
• and
• sending, by the first-stage switch to a second final-stage switch of the first fabric plane, a second fault notification data unit that includes the indication of the fabric fault.

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 fabric endpoint of the fabric endpoints is configured to send, to a first-stage switch of a first fabric plane of the plurality of fabric planes, a self-ping message destined for the fabric endpoint,
• wherein the fabric endpoint is configured to send, to a first-stage switch of a second fabric plane of the plurality of fabric planes, in response to determining the fabric endpoint has not received the self-ping message after a predetermined time, a fault data unit that includes an indication of a connectivity fault for the first fabric plane, the first fabric plane different than the second fabric plane.

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 a plurality of fabric endpoints,
• wherein a first-stage switch of a first fabric plane of the plurality of fabric planes is configured to receive an indication of a fabric fault for a second fabric plane of the plurality of fabric planes, the first fabric plane different than the second fabric plane;
• wherein the first-stage switch is configured to send, to a first final-stage switch of the first fabric plane, a first fault notification data unit that includes the indication of the fabric fault, and
• wherein the first-stage switch is configured to send, to a second final-stage switch of the first fabric plane, a second fault notification data unit that includes the indication of the fabric fault.

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 plurality of fabric planes, an indication of a fabric fault for a second fabric plane of the plurality of fabric planes, the first fabric plane different than the second fabric plane;
• send, by the first-stage switch to a first final-stage switch of the first fabric plane, a first fault notification data unit that includes the indication of the fabric fault;
• and
• send, by the first-stage switch to a second final-stage switch of the first fabric plane, a second fault notification data unit that includes the indication of the fabric fault.