Resolution Immediacy in VMM

Resolution Immediacy in VMM

Whenever an EPG associates to a VMM domain, the administrator can specify the resolution and deployment preferences for when a VLAN should be pushed to leaf interfaces.

You have three possible choices for resolution immediacy:

• Pre-provision: VLAN will be deployed on all leaf interfaces under the AAEP associated to the VMM domain regardless of VM controller of hypervisor status. This option should be used for critical services that require VLANs for them to be deployed all the time instead of dynamically only when needed. This is because this option has higher chance to hit VLAN port number limitation on a leaf since the VLAN is deployed on all interfaces in the AAEP. If AAEP is designed so that it only has interfaces connected to ACI-managed VDS, this option could be used for all EPG association. An example is vCenter and ESXi communication.

• Immediate: VLAN will be deployed on leaf interfaces only when hypervisors are detected through LLDP or CDP. This information has to be bi-direction. It means APIC compares the LLDP/CDP information from leaf switch and a VM controller to ensure that the hypervisor and leaf switches are connected correctly. If APIC has only one-sided information such as only LLDP from leaf switch, the VLAN will not be deployed. In case there is an intermediate switch in between such as Cisco UCS Fabric Interconnect, both leaf interface and hypervisor uplink should show the same Cisco UCS Fabric Interconnect in its CDP or LLDP information.

• On Demand: VLAN will be deployed on leaf interfaces only when hypervisors are detected as mentioned in Immediate mode and when at least one VM is associated to the corresponding port group. Both conditions need to be met for the VLAN to be deployed on leaf interfaces in On-Demand mode.