单项选择题
Which name describes an IPV6 host-enable tunneling technique that uses IPV4 UDP,does not require dedicated gateway tunnels,and can pass through existing IPV4 NAT gateways?（）
A. dual stack B. dynamic C. Teredo D. Manual 6to4
单项选择题 Which Cisco IOS diagnostics command can disrupt the operation of a router under high-load conditions?（）
单项选择题 Which command encrypts all plaintext passwords?（）
单项选择题 Which encapsulation type is a Frame Relay encapsulation type that is supported by Cisco routers?（）
