单项选择题
Which PPP subprotocol negotiates authentication options?（）
A. NCP B. LCP C.ISDN D.DLCI E.SLIP
单项选择题 What is the result of issuing the frame-relay map ip 192.168.1.2 202 broadcast command?（）
单项选择题 What is the first 24 bits in a MAC address called?（）
单项选择题 What occurs on a Frame Relay network when the CIR is exceeded?（）
