router eigrp 1
network 3.3.3.0 0.0.0.3
network 172.16.1.0 0.0.0.255
network 4.4.4.0 0.0.0.3
network 5.5.5.0 0.0.0.3
no auto-summary
username chl password 0 123456
username r2 password 0 abc123
username r3 password 0 abc123
interface Serial0/0/0
ip address 3.3.3.1 255.255.255.252
encapsulation ppp
ppp authentication pap
clock rate 64000
!
interface Serial0/1/0
ip address 4.4.4.1 255.255.255.252
encapsulation ppp
ppp authentication chap
clock rate 64000
!
interface Serial0/1/1
ip address 5.5.5.1 255.255.255.252
encapsulation ppp
ppp authentication chap
clock rate 64000
interface Serial0/0/0
ip address 3.3.3.2 255.255.255.252
encapsulation ppp
ppp pap sent-username chl password 0 123456
username r0 password 0 abc123
hostname r2
interface Serial0/0/0
ip address 4.4.4.2 255.255.255.252
encapsulation ppp
ppp authentication chap