Final answer:
Cisco API Leaf Nodes need to connect to every spine node and can connect to an APIC and EPGs, but they are not required to connect to every other leaf node.
Step-by-step explanation:
The question pertains to the functioning of Cisco API and its components within a network architecture. Specifically, it concerns the role of Leaf Nodes in relation to other elements in the network. Leaf Nodes in a Cisco Application Centric Infrastructure (ACI) architecture have specific roles and connections. Here are the correct applications:
- Leaf nodes do not need to connect to every other leaf node.
- Leaf nodes must connect to every spine node. This is integral to the ACI fabric architecture which follows a leaf-spine topology for efficient data center networking.
- Leaf nodes can connect to an Application Policy Infrastructure Controller (APIC), which effectively serves as the brain of the ACI fabric that manages the network policies.
- Leaf nodes can connect to an Endpoint Group (EPG), which is a logical entity within the ACI fabric that groups together similar endpoints, such as virtual or physical servers.