ACI VMM Domain Port Group Not Created: What Fix?
Refer to the exhibit. An engineer associated EPG-1 with a VMM domain called VMware/west. The VLAN pool west-VLP is configured in VMware/west, and the VMware/west is associated with the AEP called VMware/west-AEP. The corresponding port group failed to be automatically created in vCenter. Which action must the engineer take to resolve the missing port group? - 
Community Votes
75% of anonymous learners picked answer B. Votes are pick records left by other test-takers — they are not the verified answer.
Community Insight
Tests ACI VMM domain port group automation and the requirement for a populated VLAN pool, with the trap of blaming vCenter credentials or physical domain/AEP binding instead of VLAN availability.
In Cisco ACI, associating an EPG with a VMM domain triggers automatic port group creation in vCenter. For this to succeed, the VMM domain's VLAN pool must contain available VLANs; the exhibit's missing port group is resolved by including VLANs in VMware/west-VLP (B).
Choosing A, assuming wrong vCenter credentials in the AEP block port group creation; credentials affect VMM domain connectivity, but an empty VLAN pool prevents VLAN allocation for the port group.
Community Discussion (4 comments)
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Expert Analysis
Why the Answer Is Correct
In Cisco ACI, when an EPG is associated with a VMM domain, APIC resolves a VLAN from the VMM domain's VLAN pool to create the vCenter port group. If VMware/west-VLP does not contain any usable VLANs, APIC has no VLAN ID to assign, so the port group creation job fails. The exhibit's symptom is exactly a missing port group, not a VMM domain down state, which points to VLAN pool content rather than authentication. Including VLANs in west-VLP (option B) gives APIC the required VLAN range and allows the automatic port group to be created. Community members such as ed27 reinforce this by noting that APIC creates the port group in vCenter using the VLAN specified by the user.Why the Other Options Are Wrong
Option A is tempting because wrong vCenter credentials can break VMM integration, but credentials are configured on the VMM domain or AEP, and the scenario already shows the domain and EPG association working far enough to attempt port group creation. Option C sounds close, but adding only a static range is a narrower change than the actual requirement; the pool must include VLANs that APIC can allocate before a port group can be created. Option D is irrelevant because associating the AEP with a physical domain does not provide VLANs to the VMM domain's port group automation. The dominant failure here is an empty or unusable VLAN pool, not a missing physical domain binding.Community Comment Notes
The comments show a clear split, with the majority favoring B and one learner initially favoring A. prospio971 explained that APIC automatically creates the port group, but the VLAN pool must include a valid VLAN range for the process to succeed. udo2020 first argued that the only missing piece was credentials, then retracted with "It should be B and not A." ed27 added that APIC creates the port group under vCenter with VLAN specified by the user, which supports the need for an available VLAN from the pool. No commenter provided evidence that vCenter credentials are misconfigured in this exhibit.Exam Strategy
In ACI VMM scenarios, verify that the VLAN pool has available VLANs and matches the VMM domain's allocation requirements before checking vCenter credentials or AEP domain bindings. The exhibit's port group failure is almost always a VLAN pool scope or allocation issue, not an authentication problem.
Frequently Asked Questions
Why does an ACI VMM domain need VLANs in the pool to create a port group?
APIC allocates a VLAN from the VMM domain's VLAN pool for each automatic port group, so an empty VMware/west-VLP leaves no VLAN ID to assign and vCenter creation fails.
Why is wrong vCenter credentials (A) not the fix for the missing port group?
Credentials affect VMM domain inventory and connectivity, but the exhibit's EPG-to-VMM association is already in place; the direct blocker is that west-VLP has no usable VLANs for port group allocation.