多项选择题
Before installing a new, upgraded version of the IOS, what should be checked on the router, and which command should be used to gather this information?（）
A. the amount of available ROM B. the amount of available flash and RAM memory C. the version of the bootstrap software present on the router D. show version E. show processes F. show running-config
多项选择题 What can be done to secure the virtual terminal interfaces on a router?（）
多项选择题 Which of the following IP addresses can be assigned to the host devices?（）
多项选择题 Identify the four valid IPv6 addresses.（）
