Which network technology addresses these customer business needs: shrinking budgets and IT staffs, more complex networks, and an increased need for network security?（）

单项选择题What does a router do?（）

A.Stores data on the network and connects the local-area network (LAN) to the wide-area network (WAN)
B.Routes traffic down alternative paths and connects the local-area network (LAN) to the wide- area network (WAN)
C.Broadcasts data to all devices that are connected to it across the local-area network (LAN) and wide-area network (WAN)
D.Reads Media Access Control (MAC) addresses to forward messages to the correct location and connects the local-area network (LAN) to the wide-area network (WAN)

单项选择题Which component should you use to reduce collision issues on a large LAN?（）

A.Host
B.Switch
C.Printer
D.Repeater

单项选择题In the 7-layer OSI model, which layer switching will take place?（）

A.Layer one
B.Layer two
C.Layer three
D.Layer four

单项选择题Which device is used in wireless networks to send transmissions to a target area?（）

A.Optical fiber
B.Access point
C.Directional antenna
D.Omni-directional antenna

单项选择题A service provider wants to prevent the repeat of a denial of service (DoS) attack that recently disabled Internet access for several thousand customers. Which Cisco solution best matches this business need?（）

A.Network security
B.Wireless network
C.Content networking
D.Virtual Private Network (VPN)