[Reference: http://www.cisco.com/c/en/us/solutions/collateral/data-center-virtualization/application-centric-infrastructure/white-paper-c11-731961.html , When a virtual endpoint is discovered, the policy is pushed and programmed to the leaf nodes based on resolution immediacy and instrumentation immediacy, respectively. In both cases, there is an immediate and on-demand (default) option that is defined when the VMM is associated on Cisco APIC. The on-demand option conserves resources and uses the reserved space in the policy content-addressable memory (CAM) when needed., Resolution Immediacy, The first option to push a policy is immediately. All policies (VLAN, NVGRE, and VXLAN), bindings, contracts, and filters are pushed to the leaf node when the hypervisor physical NIC (pfJIC) is attached. With the on-demand option, policies are pushed to the leaf node when the pPJIC and vNIC are attached to the port group (EPG)., Deployment Immediacy, Deployment immediacy defines when the policy is programmed in hardware. If the immediate option is chosen, the policies are programmed in the policy CAM after they are received by Cisco APIC. The on-demand option programs policies in the hardware policy CAM only when reachability is learned through the data path., ]