单项选择题
A. show CHAP authentication
B. show interface serial 0
C. debug PPP authentication
D. debug CHAP authentication
E. show PPP authentication CHAP
多项选择题 Which of the following if addresses can be assigned to host devices?（）
单项选择题 How many usable sub network and usable hosts per subnet result in the network address 201.105.13.0 is sub netted with a mask of /26? （）
单项选择题 A Router with a BRI/T interface will be used for an ISDN Connection what other ISDN device is required to complete this connection? （）