单项选择题 Users have been complaining that their Frame Relay connection to the corporate site is very slow. The network administrator suspects that the link is overloaded. Based on the partial output of the Router# show frame relay pvc command shown in the graphic, which output value indicates to the local router that traffic sent to the corporate site is experiencing congestion?（）

单项选择题 On the network 131.1.123.0/27, what is the last IP address that can be assigned to a host?（）

单项选择题 All WAN links inside the ABC University network use PPP with CHAP for authentication security. Which command will display the CHAP authentication process as it occur between two routers in the network?（）