单项选择题
A. Cannot be disabled B. Cannot have the CoS changed C. Can have "Packet Drop" enabled D. Is multicast optimized E. Can have the MTU changed
A. 1 B. 2 C. 4 D. 5 E. 16
A. It’s hard-set and cannot be disabled B. It’s configurable， with an upper limit of 16 C. It’s hard-set but cannot disable best-effort and Fibre Channel D. It’s hard-set but can disable all but one class E. It’s configurable with an upper limit of eight