PPP

预先配置用户名密码

HQ#sh run | s user
username ccna password 0 cisco

PPP中PAP认证配置

Branch#sh run int s1/0
Building configuration...

Current configuration : 171 bytes
!
interface Serial1/0
ip address 192.168.1.1 255.255.255.0
encapsulation ppp
ppp pap sent-username ccna password 0 cisco

HQ(config-if)#do sh run int s1/0
Building configuration...

Current configuration : 133 bytes
!
interface Serial1/0
ip address 192.168.1.2 255.255.255.0
encapsulation ppp
ppp authentication 

注：PAP采用两次握手认证，报文中使用了明文密码。

PPP中HCAP认证配置

Branch(config-if)#do sh run int s1/0
Building configuration...

Current configuration : 177 bytes
!
interface Serial1/0
ip address 192.168.1.1 255.255.255.0
encapsulation ppp
ppp chap hostname ccna
ppp chap password 0 cisco
serial restart-delay 0

HQ(config-if)#do sh run int s1/0
Building configuration...

Current configuration : 133 bytes
!
interface Serial1/0
ip address 192.168.1.2 255.255.255.0
encapsulation ppp
ppp authentication chap

注：CHAP认证采用三次握手方式，报文中传递的是被hash后的数值

PPP

原文：https://www.cnblogs.com/zi-Chuan/p/11305011.html