問題文
A planner reads the output of the command that shows the PoE line cards of a switch, and finds that a card whose PoE ports are all empty is credited with some PoE power all the same. What does the documentation say that figure is?
選択肢
- It is the guard band of that card, which each card holds for itself so that a sudden climb in what its own PoE ports draw is met without any of them being shed, and which the IEEE standard leaves to each PoE model.
- It is the amount the card has set aside for the ports whose priority is high, which is held even while those ports are empty, and it goes back to the switch as soon as a device of a lower class is seen on one of them.
- Every line card that supports PoE carries 37 watts in its base allocation, and that amount is always part of the total.
- It is the power the card draws for itself rather than for its ports, which the output shows in the same field because the card cannot separate the two.