Which PPP subprotocol negotiates authentication options?（）

单项选择题You are working in a data center environment and are assigned the address range 10.188.31.0 23.You are asked to develop an IP addressing plan to allow the maximum number of subnets with as many as 30 hosts each.Which IP address range meets these requirements?（）

A. 10.188.31.0/27
B. 10.188.31.0/26
C. 10.188.31.0/29
D. 10.188.31.0/28
E. 10.188.31.0/25

单项选择题Assuming the default switch configuration,which approach should you use to configure the extended vlan range(1006 through 4094) on a cisco catalyst 3750 series switch?（）

A. Configure the switch to be in VTP client mode.
B. Configure the switch to be in VTP domaint mode.
C. Configure the switch to be in VTP transparent mode.
D. Configure the switch to be in VTPv2.

单项选择题In which integration method is an IPV6 packet encapsulated within an IPV4 protocol?（）

A. proxy.
B. dual-stack
C. tunneling
D. dot1q

单项选择题The enable secret command is used to secure access to which CLI mode?（）

A. user EXEC mode
B. global configuration mode
C. privileged EXEC mode
D. auxiliary setup mode

单项选择题Which statement about vlan operation on cisco catalyst switches is true?（）

 A. when a packet is received from an 802.1Q trunk,the vlan id can be determined from the source MAC address table.
B. unkown unicast frames are retransmitted only to the ports that belong to the same vlan
C. ports between switches should be configured in access mode so that vlans can span across the ports
D. broadcast and multicast frames are retransmitted to ports that are configured on different vlan.