多项选择题
A. It creates a virtual, software only, interface.
B. It provides a way to test the convergence of OSPF routing updates.
C. The mask of 255.255.255.255 is called a host mask.
D. It uses a wildcard mask of 255.255.255.255.
E. It ensures that an interface is always active for OSPF processes.
F. Loopback interfaces must be numbered 0.
单项选择题 A CCNA candidate is working on a 2600 Cisco router. The person needs to verify that the configuration register is set to boot the router IOS from flash memory and use the commands saved in the startup-configuration file. Which command will display this information, and what is the configuration register value that should be displayed?（）
多项选择题 What should be done prior to backing up an IOS image to a TFTP server?（）
单项选择题 A Cisco router has been configured, and the copy running-config startup-config command has been issued. When the router is power cycled, the router prompts with: "Would you like to enter the initial configuration dialog? [yes/no]" Why has this occurred?（）