Because we design these Cisco ACI Fabric Access Policies to support a brownfield network-centric migration, we need to make sure there is a common or shared physical domain which all AEPs are mapped to. VLAN pool assignment is also important here. Only legacy VLAN IDs deployed in the legacy data center are configured in the shared pool. This shared pool is assigned to the shared physical domain. VLANs outside of the legacy VLAN range can be assigned to the other domains which would be used for greenfield initiatives. Overtime when you fully migrate into ACI, you can then start to migrate endpoints away from the shared domain and pool into the respective compute or infra domains.
|Domain Name||VLAN Pool Name||Association|