The initial deployment with Recalculate & Deploy will configure both your border gateways and your ISN core router with the best practice configuration. The configuration between the fabrics and the ISN follow this design: I-E-I, which means iBGP - eBGP - iBGP. Your Site1 and Site2 are iBGP-based fabrics as you're already aware. The peering from the border gateways to the ISN core router will be eBGP.

Step 1 - Trigger Underlay MultiClstr FabGrp Deployment

At the top right of the Multi-CLuster fabric, locate the fabric-level Actions button:

1. Click Actions
2. Click Recalculate and Deploy

Step 2 - Deploy Underlay MultiClstr FabGrp Config

In the Deploy Configuration wizard, you can visually see the lines of configuration are required to be configured to your border gateways and core router. Again, this configuration includes VXLAN configuration for multisite under the NVE interface, underlay IFCs, overlay IFCs, and BGP.

1. In the bottom right, click Deploy All

Step 3 - Exit Deploy Configuration

Upon a successful deployment, NDFC's Deploy Configuration wizard should look as shown in the screenshot below; all green with SUCCESS messages and each switch's expected configuration progress bar also displaying as green and fully executed. If any error occurred, NDFC will display a notification and the status reverted back to Out-of-Sync.

NOTE: During this step, you may observe that ND03-2 - ISN and ND03-2 - Site2 remain in the STARTED stage. Provided that ND03-1 displays Deployment completed, you may proceed to the next step.

1. After done reviewing the deployment progress, click Close in the bottom right

Summary

You deployed the Multi-Site underlay configuration across both border gateways and the ISN core router. Nexus Dashboard automatically generated the underlay IFCs (Inter-Fabric Connections), BGP peering, and multicast configurations needed to establish the transport path between Site1 and Site2. This complex multi-device, multi-fabric deployment was accomplished with a single Recalculate and Deploy action — showcasing ND's ability to orchestrate network-wide changes effortlessly.

Continue to the next section to extend a L2VNI and L3VNI overlay between your Site1 and Site2 fabrics to establish connectivity between two servers in each fabric.