HDLC，pap，chap网络
HDlC--二层的协议
串线连接
[r1-Serial4/0/0]int s4/0/0
[r1-Serial4/0/0]ip ad 12.1.1.1 24
[r1-Serial4/0/0]ping 12.1.1.2
PING 12.1.1.2: 56 data bytes, press CTRL_C to break
Reply from 12.1.1.2: bytes=56 Sequence=1 ttl=255 time=110 ms
Reply from 12.1.1.2: bytes=56 Sequence=2 ttl=255 time=20 ms
ppp协议的pap认证
明文认证，hdlc的 升级版，两点之间不同网段可以互通
主认证
[r2-Serial4/0/0]link-protocol ppp ---默认
[r1-aaa]
[r1-aaa]local-user a password cipher 123
[r1-aaa]local-user a service-type ppp
[r1-Serial4/0/0]ppp authentication-mode pap
被认证
[r2-Serial4/0/0]link-protocol ppp
[r2-Serial4/0/0]ppp pap local-user a password cipher 123
抓包出来显示账号密码
chap认证
密文认证
[r2-Serial4/0/0]link-protocol ppp ---默认
[r1-aaa]
[r1-aaa]local-user aa password cipher 123
[r1-aaa]local-user a service-type ppp
[r1-Serial4/0/0]ppp authentication-mode chap
被认证
[r2-Serial4/0/0]link-protocol ppp
[r2-Serial4/0/0]ppp chap user aa
[r2-Serial4/0/0]ppp chap password cipher 123