Configure 3-Stage Clos Automation

The 3-stage topology has two layers of devices: Leaf and Spine. All links between Leaf and Spine must be connected. Spine nodes should not be interconnected.

There are four steps to configuring a three-stage topology: create the fabric, register the devices, validate and add the devices, and provision the configuration on the devices.

The following is an example of a three-stage fabric.

1. Create the Fabric.
2. Add a device or devices to the Fabric.
3. Validate the Fabric Topology.
   During the addition of a device to a Fabric and during Fabric configuration, Clos topology validations are performed. If the validation contains errors, the errors are reported to the user. Any Fabric topology errors can be exported to a CSV or DOT file. The following topology validations are performed:

   • Leaf nodes must connect to all the Spine nodes.
   • A Spine node must connect to all the leaf nodes.
   • A Border Leaf node connects to all the Spine nodes.
   • A Spine node connects to all the Border Leaf .
   • No more than two Leaf nodes connect to each other.
   • No more than two Border Leaf nodes connect to each other.
   • Border Leaf node and L node are not connected.
   • Spine nodes are not connected to each other.
   • Super-spine nodes are not connected to each other.
   • If a Leaf node is marked as "multi-homed", then the node must have an MCT neighbor.
   • If a Leaf node is marked as "single-homed", then the node is not connected to other Leaf nodes.
   • If a Border Leaf node is marked as "multi-homed", then the node must have an MCT neighbor.
   • If a Border Leaf node is marked as "single-homed", then the node is not connected to other Border Leaf nodes.
   • Device role (such as Leaf, Border-leaf, Spine, or Super-spine) is validated for a given device (SLX 9840 cannot be added as a leaf).
4. Configure the devices on the Fabric.