Refer to the exhibit. An engineer wants to initiate an ICMP ping from Server1 to Server2. The requirement is for the BD1 to enforce ICMP replies that follow the expected path. The packets must be prevented from taking the direct path from Leaf1 to Server1. Which action must be taken on BD1 to meet these requirements?
Answer(s): C
Option C is correct because disabling Unicast Routing on BD1 ensures that ICMP traffic from Server1 to Server2 remains within the bridged domain and follows the expected path dictated by the BD’s forwarding rules, preventing the direct Leaf1-to-Server1 path and forcing path-consistent routing via the BD. A) Flooding unknown unicast at L2 would not enforce path constraints and could still use the direct path. B) Hardware proxy for unknown unicast would alter ARP/icmp handling but not guarantee the BD1 path enforcement as required. D) ARP flooding affects address resolution behavior but does not control the overall path selection for ICMP replies.
A network engineer must configure a Cisco ACI system to detect network loops for untagged and tagged traffic. The loop must be detected and stopped by disabling an interface within 4 seconds. Which configuration must be used?
Answer(s): B
Option B is correct because: It enables loop protection with a fast-convergence mechanism that detects and shuts down an interface within 4 seconds for both untagged and tagged traffic, aligning with ACI loop-avoidance capabilities via interface-level err-disable/loop protection settings.A) Incorrect — This option does not configure the required loop-protection parameters to trigger within 4 seconds or for both untagged/tagged traffic.C) Incorrect — Lacks the necessary or correct loop-detection configuration and timed err-disable behavior.D) Incorrect — Does not implement the specified fast-loop-detection and interface-disable action for all traffic types.
Refer to the exhibit. The VMs called VM1 and VM2 are deployed on the ESXi Server in a Cisco ACI environment. VM1 has MAC address A and an IP address 192.168.1.1/24, and VM2 has MAC address B. VM1 has been shut down. Which set of actions must be taken to detect the movement of IP address 192.168.1.1/24 to MAC address B?
Answer(s): D
Option D is correct because enabling ARP flooding allows the APIC/ACI fabric to detect MAC/IP movement by broadcasting ARP requests across the VMM/ESXi environment, enabling the controller to learn that 192.168.1.1/24 has moved to MAC B after VM1 shutdown. The other options are incorrect because:A and C (Enable/Disable ARP flooding) are about ARP traffic behavior that does not inherently trigger movement detection in ACI; without ARP flooding, ARP replies may not propagate to all leafs, delaying or preventing MAC/IP binding updates.B (Disable ARP flooding) prevents the required visibility for IP-to-MAC relocation.
A Cisco ACI leaf switch receives an ARP request packet from a host that is attached to a bridge domain with unicast routing enabled. Which information does the leaf switch learn?
Option B is correct because when a leaf in ACI processes an ARP request from a host in a bridge domain with unicast routing enabled, it learns the MAC and IP addresses of the local endpoint (the host) from the ARP request/response, associating the endpoint with its EPG and BI/BD context.A) Incorrect — Local endpoint source IP address is not learned as a separate attribute; ARP handles IP-to-MAC mapping, not just source IP alone.C) Incorrect — ARP requests target another host; the leaf does not learn the remote endpoint IP just from the ARP request without a response.D) Incorrect — ARP conveys MAC and IP for the local endpoint, not a pair of source/destination IPs for routing.
Refer to the exhibit. An engineer is migrating legacy servers into the Cisco ACI environment. The requirement is to ensure that all endpoints and MAC addresses are learned properly in legacy and Cisco ACI switches. Which configuration set must be configured under the bridge domain called bd_360 to accomplish this goal?
Option B is correct because enabling L2 Unknown Unicast flooding on the bridge domain bd_360 ensures that both legacy and ACI-switch endpoints learn MAC addresses across the fabric, preserving host reachability during migration. This setting floods unknown unicast traffic to all ports in the BD, allowing legacy servers connected to non‑ARP-aware devices to be learned and reachable without relying on hardware proxy for unknown destinations. Incorrect — A and C (Hardware Proxy) rely on switch proxying of unknown unicast, which may not learn endpoints from legacy devices and can impede learning. Incorrect — D (Flood) does not distinguish ARP behavior and may not address MAC learning consistency across legacy and ACI devices.
An engineer configures an L3Out between BLeaf1 and Core1. A Cisco Nexus 9000 Series Switch runs in NX- OS mode, and the two devices must peer using OSPF. The devices in the network are configured as follows:· BLeaf1 has been configured with the IP address 10.1.0.2/31 and the router ID 0.0.0.2. · Core1 has been configured with the IP address 10.1.0.3/31 and the router ID 0.0.0.1. · On Cisco ACI, the engineer has enabled OSPF using the default OSPF settings. · The engineer has configured OSPF on the NX-OS switch using the ip router ospf ACI_peering area 1 command.Which action brings up the OSPF adjacency?
Option B is correct because OSPF adjacency requires matching area configuration on both peers; enabling Area 1 on BLeaf1 aligns with the NX-OS side configured for area 1, allowing adjacencies to form with Core1. Incorrect — A: Setting an authentication key is unnecessary here since no authentication misconfiguration is stated and default OSPF is enabled; not required to establish adjacency. Incorrect — C: Disabling the Hello Timer is inappropriate; OSPF requires standard Hello intervals unless explicitly overridden, which is not described. Incorrect — D: MTU mismatch is not indicated; the given /31 addresses and router IDs imply a layer-3 link, and MTU changes are not mandated for adjacency in this scenario.
An engineer must configure a Cisco ACI bridge domain to prevent flooding from unknown unicast frames. Which action must be configured in Cisco ACI to accomplish this goal?
Option D is correct because enabling the bridge domain in optimized mode reduces flooding by using MAC address learning and distribution optimized for the fabric, thereby containing unknown unicast flood within learned scope. ACI optimized mode minimizes flood scope and leverages Control Plane learning to prevent unnecessary unknown unicast flooding.A) Incorrect — Flood in Encapsulation would cause flooding of unknown unicast frames, not prevent it. B) Incorrect — Clear Remote MAC Entries clears learned MACs but does not prevent flooding. C) Incorrect — Disable Remote EP Learn affects EP learning behavior, not directly the unknown unicast flood control within a bridge domain.
A Cisco ACI leaf switch learns the source IP address of a packet that enters the front panel port of the switch.Which bridge domain setting is used?
Option D is correct because a leaf switch learning the source IP address of an incoming packet implies unicast routing is active; the packet is processed at L3, and the bridge domain participates in routed interfaces rather than L2 flooding behaviors.A) ARP Flooding — Incorrect: ARP flooding occurs for unknown ARP requests within a broadcast domain, not for learning source IPs to perform L3 routing decisions.B) L3 Unknown Multicast Flooding - Flood — Incorrect: Unknown multicast flooding handles multicast frames, not the learning of a single source IP per unicast ingress.C) L2 Unknown Unicast - Hardware proxy — Incorrect: Hardware proxy for unknown unicast is used to optimize L2 forwarding, not to determine source IP learning for routed traffic.
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