router2:

Router>en

Router#conf t

Enter configuration commands, one per line. End with CNTL/Z.

Router(config)#hostname ccna

ccna(config)#int s0/0/0

ccna(config-if)#ip add 10.0.0.2 255.255.255.252

ccna(config-if)#encapsulation ppp

ccna(config-if)#clock rate 64000

ccna(config-if)#exit

ccna(config)#username ccnp password 123

ccna(config)#int s0/0/0

ccna(config-if)#ppp authentication chap

ccna(config-if)#no shutdown

router3:

Router>en

Router#conf t

Enter configuration commands, one per line. End with CNTL/Z.

Router(config)#hostname ccnp

ccnp(config)#int s0/0/0

ccnp(config-if)#ip add 10.0.0.1 255.255.255.252

ccnp(config-if)#encapsulation ppp

ccnp(config-if)#exit

ccnp(config)#username ccna password 123

ccnp(config)#int s0/0/0

ccnp(config-if)#ppp authentication chap

ccnp(config-if)#no shutdown

两个接口都是s0/0/0