多项选择题 Your boss， Miss ，is interested in CEF.  What should you tell her？ （）

单项选择题 Refer to the exhibit. DHCP snooping is enabled for selected VLANs to provide security on the network.  How do the switch ports handle the DHCP messages？（）

单项选择题 Exhibit： You work as a network administrator at. You study the exhibit carefully.  Which configuration on the HSRP neighboring device ensures that it becomes the active HSRP device in the event that port fa1/1 on 1 goes down？ （）