Which two statements are true regarding Tenant Bridge Domain ARP forwarding modes? (Choose two.)

Question

Options

• AARP flooding occurs only within the encapsulation VLANs.
• BACI Fabric can team up to a million end points if ARP flooding is not configured.
• CARP handing is enabled by default which means unicast routing is used to forward the ARP packet.
• DARP handing is disabled by default which means unicast routing is used to forward the ARP packet
• EARP flooding must be configured if internal hosts are using an external IP gateway

• A
  77% (23)
• B
  3% (1)
• C
  7% (2)
• D
  13% (4)

Explanation

A and E are correct because in Cisco ACI Bridge Domains, ARP flooding - when enabled - is scoped strictly to the encapsulation VLANs associated with that BD, preventing fabric-wide broadcast storms (A). Additionally, if hosts rely on an external IP gateway (outside the ACI fabric), ACI's built-in proxy ARP mechanism cannot resolve those addresses from the COOP endpoint database, so ARP flooding must be explicitly configured to reach that external gateway (E).

Why the distractors are wrong:

• B - The "million endpoints" figure is fabricated; ACI scale limits are real but this specific claim has no basis in Cisco documentation.
• C - States ARP handling is enabled by default, which is backwards; ARP flooding is disabled by default in ACI BDs. The logic is also self-contradicting (flooding enabled ≠ unicast forwarding).
• D - While it correctly states flooding is disabled by default, "ARP handling" in ACI refers to the proxy ARP/COOP mechanism, which is enabled (not disabled) by default - making the premise of D incorrect.

Memory tip: Think of ACI's default behavior as "smart unicast first" - ACI proxies ARP silently via its endpoint database. Flooding only enters the picture for external gateways (E) and is always VLAN-contained when it does occur (A). If the distractor mentions a suspiciously round number like a million, it's almost certainly a fabrication.

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