CCNA Practice Exam Test Sample – Question 292

Which command is used to enable CHAP authentication, with PAP as the fallback method, on a serial interface?

A. Router(config-if)# ppp authentication chap fallback ppp
B. Router(config-if)# ppp authentication chap pap
C. Router(config-if)# authentication ppp chap fallback ppp
D. Router(config-if)# authentication ppp chap pap

Correct Answer: B
Section: WAN Technologies

Explanation:
This command tells the router first to use CHAP and then go to PAP if CHAP isn’t available.