Exam 300-620 topic 1 question 79 discussion

The answer is D From a physical perspective, the different Pods are interconnected by leveraging an “Inter-Pod Network” (IPN). Each Pod connects to the IPN through the spine nodes; the IPN can be as simple as a single Layer 3 device, or can be built with a larger Layer 3 network infrastructure. https://www.cisco.com/c/en/us/solutions/collateral/data-center-virtualization/application-centric-infrastructure/white-paper-c11-737855.html#Introduction

I think this question is outdated: Beginning with Cisco APIC Release 5.2(3), the ACI Multi-Pod architecture is enhanced to support connecting the spines of two Pods directly with back-to-back ("B2B") links. With this solution, called Multi-Pod Spines Back-to-Back, the IPN requirement can be removed for small ACI Multi-Pod deployments. Multi-Pod Spines Back-to-Back also brings operational simplification and end-to-end fabric visibility, as there are no external devices to configure. For more information, please refer to the paper at the link below: https://www.cisco.com/c/en/us/td/docs/dcn/aci/apic/kb/cisco-multipod-b2b.html