单项选择题 When you enter the interface command auto qos voip cisco-phone on a port at the edge of a network, how does the Cisco Catalyst switch detect if a Cisco IP Phone is connected to the port? （）

单项选择题 Which switching engine enables the access control list lookup to be committed to hardware? （）

多项选择题 Which two differentiators make RSTP the preferred protocol for preventing Layer 2 loops in aswitched network environment?（） (Choose two.)