Question 400
During a GPU datacenter maintenance window, an engineer discovers: A 400-Gbps breakout assembly is connected with reversed lane mapping so one logical child port terminates at the wrong peer while other child ports work. Which repeatable operational safeguard best prevents recurrence of this failure?
Explanation
Correct Answer
This preventive practice addresses the underlying failure (Physical breakout assemblies can expose partial link success while individual logical lanes are miswired.) and supports continued assurance through: Every expected child link resolves to its intended peer and a port-by-port test detects no unintended cross-connection.
Incorrect Answers
This prevention control targets another operational risk: A technician lands two adjacent GPU host fibers on the wrong switch ports, and both links show up yet a multi-rail collective runs over one rail. The currently reported mechanism remains: Physical breakout assemblies can expose partial link success while individual logical lanes are miswired.
This prevention control targets another operational risk: A rack expansion replicates old patch labels, and engineers cannot tell which high-speed trunk belongs to each new GPU server during a fault. The currently reported mechanism remains: Physical breakout assemblies can expose partial link success while individual logical lanes are miswired.
This prevention control targets another operational risk: An LLM platform signs off infrastructure after HPL and NCCL pass, but the real NeMo run fails because the configured container cannot access the required tokenizer and approved model artifacts. The currently reported mechanism remains: Physical breakout assemblies can expose partial link success while individual logical lanes are miswired.