Which option describes the correct sequence to discover an ESX server in the fabric without a blade switch or multiple Layer 2 hops?

Question

Options

• AThe leaf sends LLDP/CDP to the ESX, the ESX sends parsed UDP/CDP information to the vCenter, the APIC receives LLDP/CDP information from the vCenter, and the APIC downloads the policy for VMs behind the ESX to the leaf node.
• BThe APIC downloads the policy for VMs behind ESX to the leaf node, the leaf sends LLDP/CDP to the ESX, the ESX sends parsed LLDP/CDP information to the vCenter, and the APIC receives LLDP/CDP information from the vCenter.
• CThe ESX sends parsed LLDP/CDP information to the vCenter, the leaf sends LLDP/CCp to the ESX, the APIC downloads the policy for VMs behind the ESX to the leaf node, and the APIC receives LLDP/CDP information from the vCenter.
• DThe ARC receives LLDP/CDP information from the vCenter, the APIC downloads policy for VMs behind ESX to the leaf node, the leaf sends LLDP/CCP to the ESX, and the ESX sends parsed LLDP/CDP information to the vCenter.

• A
  9% (3)
• B
  69% (24)
• C
  6% (2)
• D
  17% (6)

Explanation

Option B is correct because in Cisco ACI's VMM integration flow, the APIC must first push policy to the leaf node before any discovery can begin - the leaf needs that configuration to know how to handle traffic and initiate LLDP/CDP toward the ESX host. Once the leaf sends LLDP/CDP, the ESX host parses it and reports the topology information up to vCenter, and finally the APIC retrieves that information from vCenter via its VMM domain integration, completing the discovery loop.

A is wrong because it skips the policy download entirely - the leaf cannot meaningfully send LLDP/CDP in the correct context without first receiving policy from the APIC.

C is wrong because it places the ESX-to-vCenter reporting step before the leaf has even sent LLDP/CDP to the ESX, which is causally impossible - the ESX can't forward what it hasn't received yet.

D is wrong because it reverses the entire sequence and starts with the APIC receiving information it couldn't have yet; it also contains a suspicious "ARC" label (likely a deliberate distractor) and puts the leaf's LLDP/CDP transmission near the end, after the ESX has already reported to vCenter.

Memory tip: Think of it as "Policy → Probe → Parse → Report" - the APIC sets the stage (policy), the leaf probes with LLDP/CDP, ESX parses and reports to vCenter, and APIC pulls the result. The APIC always acts first (policy push) and last (receiving discovery info).

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