Ccna routing and Switching Complete Study Guide

config t

RouterA(config)#

int s0

RouterA(config-if)#

ppp authentication chap pap

RouterA(config-if)#

^Z

If both methods are configured on the same line as I’ve demonstrated here, then only the 

first method will be used during link negotiation. The second acts as a backup just in case 

the first method fails.

There is yet another command you can use if you’re using PAP authentication for some 

reason. The 

ppp pap sent-username <

username> password

 command enables 

outbound PAP authentication. The local router uses the username and password that the 

ppp pap sent-username

 command specifies to authenticate itself to a remote device. The 

other router must have this same username/password configured as well.