Which Component Provides Layer 2 and Layer 3 Connectivity Across ACI Pods?
Which component provides Cisco ACI fabric with Layer 2 and Layer 3 connectivity across pods and physical locations?
Community Votes
57% of anonymous learners picked answer A. Votes are pick records left by other test-takers — they are not the verified answer.
Community Insight
It tests whether you can separate the Multi-Pod transport component (the IPN) from the encapsulation technology (VXLAN) that rides over it — the trap is reading 'Layer 2 and Layer 3' and immediately choosing the VXLAN overlay.
Cisco ACI Multi-Pod extends the fabric beyond a single site by linking pods through the Inter-Pod Network (IPN), a routed transport that carries VXLAN traffic between spine switches. This page establishes why the IPN is the component that provides Layer 2 and Layer 3 connectivity across pods and physical locations, and why the VXLAN overlay alone does not answer the question.
The most common wrong choice is B (VXLAN overlay), because VXLAN is what actually carries Layer 2 and Layer 3 endpoint traffic between pods; learners forget that the overlay requires a physical transport component — the Inter-Pod Network — and that the question asks for the component, not the data-plane format.
Community Discussion (4 comments)
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Expert Analysis
Why the Answer Is Correct
The Inter-Pod Network is the transport component of Cisco ACI Multi-Pod: it is the routed network (typically OSPF between the spine switches of each pod) that physically links separate pods and separate physical locations. Spine switches inside different pods never connect directly, so every packet that must cross a pod boundary is carried over the IPN inside the fabric's VXLAN header. Because the IPN is what makes inter-pod forwarding possible at all, it is the component that gives the ACI fabric Layer 2 and Layer 3 connectivity across pods and physical locations. Remove the IPN and each pod becomes an isolated fabric island with no cross-pod endpoint reachability.Why the Other Options Are Wrong
Option B (VXLAN overlay) describes the encapsulation the fabric uses for endpoint-to-endpoint traffic; it is a technology riding on top of the IPN rather than the component that interconnects pods, and by itself it transports nothing if no routed underlay exists. Option C (COOP control plane) is the spine protocol that distributes endpoint and fabric information so remote endpoints are known, which is control-plane reachability, not the data-path connectivity the question asks about. Option D (Cisco APIC control cluster) is the management and policy layer — it configures and monitors the fabric but forwards no tenant traffic and provides no cross-pod transport.Community Comment Notes
The thread splits almost evenly, with a slight majority landing on the IPN: prospio971 explains that "The IPN is a routed network that connects the spine switches of different pods", which matches the transport role the exam is probing, and mdriraa states plainly that "It must be Interpod Network". The dissenting vote from 2eb1ea8 argues that "It is the use of the VXLAN overlay technology in the data-plane that provides seamless" connectivity regardless of where an endpoint sits, which is technically true about the overlay but not about the component that links pods. Another commenter votes A while quoting the white paper line that connectivity is offered "independently from the physical location where they are connected", which is precisely why this item is confusing — Cisco's solution-level wording blends the overlay's capability with the IPN that makes it possible.Official Reference
Exam Strategy
When an item asks which 'component provides connectivity', separate the four roles: transport (IPN), encapsulation (VXLAN), control plane (COOP), and management (APIC) — Cisco deliberately words these questions to pull you toward the forwarding technology you associate with Layer 2 and Layer 3. For Multi-Pod scenarios, remember that spines in different pods never peer directly; all inter-pod traffic must cross the IPN, which is the strongest clue that the IPN is the answer.
Frequently Asked Questions
Why is the VXLAN overlay not the component providing cross-pod connectivity?
VXLAN is the encapsulation the ACI fabric uses end to end, but it still needs the Inter-Pod Network to carry its packets between pods, so the IPN is the connectivity component.
How does the COOP control plane differ from the Inter-Pod Network in ACI Multi-Pod?
COOP is a spine control-plane protocol that shares endpoint reachability information between pods, while the IPN is the data-path network that actually transports the VXLAN traffic.