An engineer must integrate a Cisco ACI fabric with VMware and discover an ESXi host using LLDP. Two EPGs have been created and associated with the VMM domain. The engineer must configure the ACI such that contracts are pushed to the ACI leaf switches when the VM is mapped to EPG and the contracts are removed when LLDP is disabled. Which configuration must be selected to meet these requirements?
Resolution immediacy specifies when the policy is implemented in the network hardware. The requirement demands that contracts be pushed to the ACI leaf switches only when the ESXi host is discovered via LLDP and removed when LLDP is disabled. This implies that the policies should only be applied when the endpoints (VMs) are actually present. Hence, the correct configuration that meets this requirement is Resolution immediacy: On-Demand, where the policy is applied dynamically based on the presence of endpoints.
Immediate—Specifies that EPG policies (including contracts and filters) are downloaded to the associated leaf switch software upon ESXi host attachment to a DVS. LLDP or OpFlex permissions are used to resolve Immediate—Specifies that the policy is programmed in the hardware policy CAM as soon as the policy is downloaded in the leaf software. On Demand—Specifies that a policy (for example, VLAN, VXLAN bindings, contracts, or filters) is pushed to the leaf node only when an ESXi host is attached to a DVS and a VM is placed in the port group (EPG). Pre-provision—Specifies that a policy is downloaded to a leaf switch even before a VM controller is attached to the virtual switch . This pre-provisions the configuration on the switch. https://www.cisco.com/c/en/us/td/docs/switches/datacenter/aci/apic/sw/1-x/aci-fundamentals/b_ACI-Fundamentals/b_ACI-Fundamentals_chapter_01011.html
Swaying towards B as the answer - https://learnduty.com/cisco-aci/cisco-aci-resolution-and-deployment-immediacy-explained/
deployment immediacy is when policy is written to the CAM.
On Demand: VLAN will be deployed on leaf interfaces only when: 1- Hosts are detected via LLDP/CD (basically immediate) 2- At least one VM is associated to the EPG corresponding port group.
B. Resolution immediacy: On-Demand This will ensure that contracts are only applied and enforced when the endpoints (VMs) are actually discovered and present, and they are removed when LLDP is disabled, reflecting the dynamic presence or absence of the endpoints.
Answer is B: • On Demand—Specifies that a policy (for example, VLAN, VXLAN bindings, contracts, or filters) is pushed to the leaf node only when an ESXi host is attached to a DVS and a VM is placed in the port group (EPG). The policy will be downloaded to leaf when host is added to VMM switch and virtual machine needs to be placed into port group (EPG). CDP/LLDP neighborship from host to leaf is required.
C is correct
To meet the requirements where contracts are pushed to the Cisco ACI leaf switches when a VM is mapped to an EPG and removed when LLDP is disabled, the following configuration must be selected: Configuration Option: On-Demand Resolution for VMM Domain
In Cisco ACI, Resolution Immediacy determines when the policies (such as contracts and VLAN mappings) for an endpoint group (EPG) are pushed to the leaf switches. To meet the requirement that contracts are pushed to the ACI leaf switches only when the VM is mapped to an EPG via LLDP and removed when LLDP is disabled, the Resolution Immediacy must be set to On-Demand.