GNS3 PPP authentication PAP

Password Authentication Protocol :
This is the configuration for both routers

router 1 configuration

R1(config)#username R2 password cisco
R1(config)#interface Serial1/0
R1(config-if)#ip address 192.168.6.1 255.255.255.0
R1(config-if)#no shutdown
R1(config-if)#encapsulation ppp
R1(config-if)#ppp authentication pap
R1(config-if)#ppp pap sent-username R1 password 0 cisco

router 2 configuration

R2(config)#username R1 password cisco
R2(config)#interface Serial1/0
R2(config-if)#ip address 192.168.6.2 255.255.255.0
R2(config-if)#no shutdown
R2(config-if)#encapsulation ppp
R2(config-if)#ppp authentication pap
R2(config-if)#ppp pap sent-username R2 password 0 cisco

this is the topology if you want to download it