Quick reroute in Clos networks

A spine network device in a Clos network comprising a plurality of spine network devices and a plurality of leaf network devices, the spine network device comprising:

• one or more processors;
• and
• a computer-readable storage medium having stored thereon program code that, when executed by the one or more processors, causes the one or more processors to:
• configure a set of Equal-Cost Multi-Path (ECMP) groups on the spine network device, the set of ECMP groups including an ECMP group that comprises the plurality of leaf network devices except for a first leaf network device;
• detect a connectivity failure between the spine network device and the first leaf network device;
• and
• in response to the detecting, update one or more routes in a routing table of the spine network device, wherein the one or more routes are associated with one or more hosts that are connected to the first leaf network device, and wherein updating each route in the one or more routes comprises changing the route to point to the ECMP group as a next hop.

A method for implementing quick reroute in a Clos network comprising a leaf layer with a plurality of leaf network devices, a spine layer with a plurality of spine network devices, and a super-spine layer with a plurality of super-spine network devices, the method comprising:

• configuring, by a first spine network device in the plurality of spine network devices, a first set of Equal-Cost Multi-Path (ECMP) groups on the first spine network device, the first set of ECMP groups including a first ECMP group that comprises the plurality of super-spine network devices;
• detecting, by a first spine network device, a connectivity failure between the first spine network device and a first leaf network device in the plurality of leaf network devices;
• and
• in response to the detecting, updating, by the first spine network device, one or more routes in a routing table of the first spine network device, wherein the one or more routes are associated with one or more hosts that are connected to the first leaf network device, and wherein updating each route in the one or more routes comprises changing the route to point to the first ECMP group as a next hop.