单项选择题
Which command can be used from a PC to verfy the connectivity between host that connect through path?（）
A. tracert address B. ping address C. arp address D. traceroute address
单项选择题 What is the function of the command switchport trunk native vlan 999 on a switch?（）
单项选择题 Which IPsec security protocol should be used when confidentiality is required?（）
单项选择题 Which command can you use to manually assign a static IPV6 address to a router interface?（）
