What are two design constraints in a standard spine and leaf architecture?

B (Spine must connect to every leaf):Spine-and-leaf designs require full mesh connectivity between spines and leaves to ensure consistent low-latency, non-blocking performance.

E (Leaf must connect to every spine):Each leaf switch must connect to all spine switches to guarantee even load distribution and fault tolerance.

Other options explained:

A: Spine switches should not connect to each other in standard spine-and-leaf designs.

C: Leaf switches do not connect to each other directly.

D: Endpoints connect to leaf switches, not spines.