With your Site1 and Site2 fabrics created and verified to configured and functioning correctly, the next step is to move them in a Multi-Site Domain (MSD), but first, a Fabric needs to be created for the router(s) that will act as the Inter-Site Network (ISN) providing connectivity between your Data Center sites. Again, NDFC can fully manage these devices as well in fabrics that are created very similar to the previous External L3 Fabric.

Step 1 - Exit ExtL3 Fabric

1. Navigate back to NDFC and in the top right corner, click the to close your ExtL3 fabric

Step 2 - Launch Create Fabric Wizard

In the Fabrics pane, you should now see your Site1, Site2, and ExtL3 fabrics present. Navigate to the far right of the pane and locate Actions:

1. Click Actions
2. Then, click Create Fabric

Step 3 - Name Your External Fabric

In the Create Fabrics popup wizard:

1. Name the fabric: ISN
2. Then, click Choose Fabric

Step 4 - Select Type of Fabric

The fabric type for this fabric will the same as your ExL3 fabric; an External Connectivity Network. In the Select Type of Fabric popup:

1. Click External Connectivity Network
2. Then click Select

Step 5 - Define General Parameters

The first section is General Parameters where you define namely the External Fabric's BGP ASN, i.e. the ASN to be configured to the external device(s). For the purposes of this lab, there is no additional Fabric Settings that are required. Subsequent parameters are sufficient for most environments as the Fabric Settings provide configuration parameters out of the box, e.g. a range of sub-interfaces for use on the Border Leaf and externally managed device.

1. Click General Parameters
2. Set the BGP ASN to 65444
3. Uncheck the checkbox for Fabric Monitor Mode
4. Click Save in the bottom right

Step 6 - View ISN Fabric Sidebar

In addition to the Fabric Health column, you can click on any fabric listed to get a quick view sidebar that pops out on the right side of your screen with details about the fabric:

1. Click ISN
2. A sidebar should pop out on the right with more high-level information. This will populate more as you progress throughout the lab.
3. To navigate to your ISN fabric, click the expand button . You could also just double click the Fabric Name ISN to navigate to the fabric

Step 7 - View ISN Fabric Dashboard

Once clicking the expand button in the fabric popout sidebar or double-clicking the ISN fabric name, you are presented with the overall fabric dashboard overview. This dashboard looks slightly different, but like your previous fabrics, at this point, the dashboard isn't very interesting, but in the next few sections, you will bring this dashboard to life!

Continue to the next section to discover and import your core router that will act as your ISN router into your ISN fabric.