Which command shows your active Telnet connections?（）

单项选择题Which commands is necessary to permit SSH or Telnet access to a cisco switch that is otherwise configured for these vty line protocols?（）

A. transport type all
B. transport output all
C. transport preferred all
D. transport input all

单项选择题What is the OSPF default frequency,in seconds,at which a cisco router sends hello packets on a multi-access network?（）

A. 10
B. 40
C. 30
D. 20

单项选择题Which dose the frame-relay interface-dlci command configure?（）

A. remote DLCI on the main interface
B. local DLCI on the main interface
C. local DLCI on the subinterface
D. remote DLCI on the subinterface

单项选择题Which command can be a router to verify the layer 3 path to a host?（）

A. traceroute address
B. tracert address
C. ssh address
D. telnet address

单项选择题A company has a small network,consisting of a single switch and a single router.The switch has been configured with two vlans,and route-on-a-stick is being configured on the router for inter-vlan routing.A trunk is configured to connect the switch to the router.What is the minimum number of router subinterfaces that are required for all the vlans to communicate?（）

A. one
B. three
C. two
D. zero