10.5-PPP PAP认证

PAP认证：两次握手，明文认证。目前运营商的PPPoE就是采用PAP认证

实验ensp工程文件和所有抓包文件下载地址：
https://download.csdn.net/download/i12344/85235251

配置示例：

R2：Server认证端配置：

[R2-aaa]local-user orcy password cipher 123  //创建用户orcy、密码123
Info: Add a new user.
[R2-aaa]local-user orcy service-type ppp
[R2-aaa]int s4/0/0
[R2-Serial4/0/0]ip add 12.1.1.2 24	
[R2-Serial4/0/0]ppp authentication-mode pap  //开启PAP认证

R1被认证方不做任何配置，开启端口后，抓包可以看到Configure-Reject报文。如图2

R1：Client被认证方配置错误密码：

[R1]int s4/0/0
[R1-Serial4/0/0]ip add 12.1.1.1 24
[R1-Serial4/0/0]ppp pap local-user orcy password simple 456  //正确密码是123

此时，开启端口抓包，则可以看到Authenticate-Nak密码配置错误的报文。如图3

R1：Client被认证方配置正确的密码：

此时可以看到认证过程 Authenticate-Request报文包含明文用户名和密码，应为验证正确，认证成功，认证方发回Authenticate-Ack报文。如图4

此时，R1和R2链路已经打通

[R1]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=50 ms
    Reply from 12.1.1.2: bytes=56 Sequence=2 ttl=255 time=20 ms
    Reply from 12.1.1.2: bytes=56 Sequence=3 ttl=255 time=10 ms
    Reply from 12.1.1.2: bytes=56 Sequence=4 ttl=255 time=10 ms
    Reply from 12.1.1.2: bytes=56 Sequence=5 ttl=255 time=20 ms

  --- 12.1.1.2 ping statistics ---
    5 packet(s) transmitted
    5 packet(s) received
    0.00% packet loss
    round-trip min/avg/max = 10/22/50 ms