This page is a reference and takeway for you to understand, how Sites are added to the MSO.
Once the APIC has all the Day 0 configuration in place, you can proceed to that APIC cluster as a Site within the MSO. The steps below are an example of adding Site 3, the ACI fabric you have used up to this point in the lab, to the shared MSO you will be using to perform policie across data centers next!