子网172.16.0.0/22有（）个可用的IP地址

A.1022

B.1024

C.256

D.254

与动态路由协议相比，静态路由有哪些优点?()

A.带宽占用少

B.简单

C.路由器能自动发现网络拓扑变化

D.路由器能自动计算新的路由

当配置一个CISCO的路由器时，缺省的DR和BDR优先级是（）。

A.0

B.1

C.16

D.255

哪一个命令可以设置路由器特权用户的“明文密码”（）

A.enable password

B.password

C.enable secret

D.secret

The network security policy for Ezonexam requires that only one host be permitted to attach dynamically to each switch interface. If that policy is violated, the interface should be automatically disabled. Which two commands must the Ezonexam network administrator configure on the 2950 Catalyst switch to meet this policy? (Choose two)

A．SWEzonexam1(config-if)# switchport port-security maximum 1

B．SWEzonexam1(config)# mac-address-table secure

C．SWEzonexam1(config)# access-list 10 permit ip host

D．SWEzonexam1(config-if)# switchport port-security violation shutdown

E．SWEzonexam1(config-if)# ip access-group 10

Which of the following components must be elected before the Spanning Tree Protocol can converge in a switched LAN?

A. Designated ports.

B. Duplex operating mode.

C. Fast mode ports.

D. Root bridge.

E. Root ports.

F. BDPU priority.

OSPF协议中DR和BDR使用的组播地址是（）

A.224.0.0.1

B.224.0.0.5

C.224.0.0.8

D.224.0.0.9

为了使配置私有IP的设备能够访问互联网，应采用的技术是()

A.NAT

B.VLAN

C.ACCESS-LIST

D.DDR

Ezonexam has a Class C network and you need ten subnets. You wish to have as many addresses available for hosts as possible. Which one of the following subnet masks should you use?

A．255.255.255.192

B．255.255.255.224

C．255.255.255.240

D．255.255.255.248

E．None of the above