Which two statements are true regarding ARP request/response on an ACI Fabric? (Choose two.)

Question

Options

• AARP requests come in on the elected/designated FD encapsulation VLAN under the BD.
• BARP request can be captured using tcpdump" on spine switches.
• CARP traffic is handled by the broadcom ASIC it the two endpoints are in the same EPG and the same FD VLAN.
• DARP requests are sent to CPU only if they are for the Bridge Domain SVI IP address.
• EELAM can be used to capture ARP request/response frames in the Leaf front panel Broadcom ASIC.

• A
  73% (22)
• B
  7% (2)
• C
  3% (1)
• D
  17% (5)

Explanation

Option A is correct because in ACI, when an ARP request enters the fabric, it arrives on the elected/designated Flood Domain (FD) encapsulation VLAN associated with the Bridge Domain - this is how ACI organizes Layer 2 flooding boundaries. Option E is correct because ELAM (Embedded Logic Analyzer Module) is the purpose-built hardware diagnostic tool for capturing frames - including ARP - as they traverse the Broadcom ASIC pipeline on leaf front-panel ports.

Why the distractors are wrong:

• B is wrong because ARP is a Layer 2 construct handled at the leaf level; spine switches in ACI don't connect to endpoints and don't process ARP frames, making tcpdump on a spine useless for this purpose.
• C is wrong because ACI's policy model means ARP handling isn't purely offloaded to the Broadcom ASIC even within the same EPG/FD VLAN - ARP proxy and flooding decisions involve more than just ASIC-level switching.
• D is wrong because it's too narrow; ARP requests are punted to CPU for multiple reasons (e.g., proxy ARP for unknown endpoints, BD flooding policies), not exclusively for the BD SVI IP address.

Memory tip: Think "A-E = Arrival + ELAM" - ARP Arrives on the designated FD VLAN (A), and you debug it with ELAM at the leaf edge (E). Both answers deal with how ARP physically enters and is inspected at the leaf, not at the spine.

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