What must be set correctly when configuring a serial interface so that higher-level protocols calculate the best route?（）

单项选择题When configuring a serial interface on a router, what is the default encapsulation?（）

A. atm-dxi
B. frame-relay
C. hdlc
D. lapb
E. ppp

单项选择题Which command displays CPU utilization?（）

A. show protocols
B. show process
C. show system
D. show version

单项选择题Which command is used to debug a ping command?（）

A. debug icmp
B. debug ip icmp
C. debug tcp
D. debug packet

单项选择题Which command is used to see the path taken by packets across an IP network?（）

A. show ip route
B. show route
C. traceroute
D. trace ip route

单项选择题Which command would you configure globally on a Cisco router that would allow you to view directly connected Cisco devices?（）

A. enable cdp
B. cdp enable
C. cdp run
D. run cdp