单项选择题
A. Store-and-forward switching
B. Microsegmentation
C. Transparent bridging
D. Fragment-free switching
E. Virtual LANs
F. Cut-through switching
单项选择题 Which of the following options lists the steps in PPP session establishment in the correct order?（）
单项选择题 Which Frame Relay feature is responsible for transmitting keepalives to ensure that the PVC does not shut down because of inactivity?（）
多项选择题 Which characteristics are representative of a link-state routing protocol?（）