实验30:CHAP 认证
1.
实验目的
通过本实验，读者可以掌握如下技能：
(1) CHAP 认证的配置方法（使用“username 用户名 password 密码” 命令为对方配置用户名和密码，需要注意的是两方的密码要相同）
2.
实验拓扑
如图。
3.
实验步骤
注：
CHAP 验证的最简单配置，也是实际应用中最常用的配置方式。配置时要求用户
名为对方路由器名，而双方密码必须一致。原因是：由于CHAP 默认使用本地路由器的名字
做为建立PPP 连接时的识别符。路由器在收到对方发送过来的询问消息后，将本地路由器的
名字作为身份标识发送给对方；而在收到对方发过来的身份标识之后，默认使用本地验证方
法，即在配置文件中寻找，看看有没有用户身份标识和密码；如果有，计算加密值，结果正
确则验证通过；否则验证失败，连接无法建立。
r0(config-if)#ip add 172.16.1.1 255.255.255.0
r0(config-if)#no sh
r0(config-if)#
*Mar 1 00:05:08.115: %LINK-3-UPDOWN: Interface Serial0/0, changed state to up
r0(config-if)#
*Mar 1 00:05:09.123: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0/0, changed state to up
r0(config-if)#
*Mar 1 00:05:37.155: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0/0, changed state to down
r0(config-if)#
*Mar 1 00:06:07.155: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0/0, changed state to up
r0(config-if)#exit
r0(config)#int s0/0
r0(config-if)#username r1 pass cisco
r0(config)#int s0/0
r0(config-if)#enc ppp
r0(config-if)#ppp authen chap路由器的两端串口采用PPP 封装，并采用配置CHAP 验证：
r0(config-if)#do sh ip int b
Interface IP-Address OK? Method Status Protocol
FastEthernet0/0 unassigned YES unset administratively down down
Serial0/0 172.16.1.1 YES manual up up
FastEthernet0/1 unassigned YES unset administratively down down
Serial0/1 unassigned YES unset administratively down down
r0(config-if)#do debug ppp authen
PPP authentication debugging is on
r0(config-if)#do ping 172.16.1.2
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 172.16.1.2, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 4/18/36 ms
r0(config-if)#sh
r0(config-if)#no sh
*Mar 1 00:08:51.079: %LINK-5-CHANGED: Interface Serial0/0, changed state to administratively down
*Mar 1 00:08:52.079: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0/0, changed state to down
r0(config-if)#no sh
r0(config-if)#
*Mar 1 00:08:54.551: Se0/0 PPP: Using default call direction
*Mar 1 00:08:54.559: Se0/0 PPP: Treating connection as a dedicated line
*Mar 1 00:08:54.559: Se0/0 PPP: Session handle[5A000004] Session id[2]
*Mar 1 00:08:54.563: Se0/0 PPP: Authorization required
*Mar 1 00:08:54.567: %LINK-3-UPDOWN: Interface Serial0/0, changed state to up
*Mar 1 00:08:54.663: Se0/0 CHAP: O CHALLENGE id 2 len 23 from "r0"
*Mar 1 00:08:54.731: Se0/0 CHAP: I CHALLENGE id 3 len 23 from "r1"
*Mar 1 00:08:54.747: Se0/0 CHAP: Using hostname from unknown source
*Mar 1 00:08:54.747: Se0/0 CHAP: Using password from AAA
*Mar 1 00:08:54.747: Se0/0 CHAP: O RESPONSE id 3 len 23 from "r0"
*Mar 1 00:08:54.779: Se0/0 CHAP: I RESPONSE id 2 len 23 from "r1"
*Mar 1 00:08:54.779: Se0/0 PPP: Sent CHAP LOGIN Request
*Mar 1 00:08:54.791: Se0/0 PPP: Received LOGIN Response PASS
*Mar 1 00:08:54.795: Se0/0 PPP: Sent LCP AUTHOR Request
*Mar 1 00:08:54.803: Se0/0 PPP: Sent IPCP AUTHOR Request
r0(config-if)#
*Mar 1 00:08:54.803: Se0/0 CHAP: I SUCCESS id 3 len 4
*Mar 1 00:08:54.823: Se0/0 LCP: Received AAA AUTHOR Response PASS
*Mar 1 00:08:54.827: Se0/0 IPCP: Received AAA AUTHOR Response PASS
*Mar 1 00:08:54.827: Se0/0 CHAP: O SUCCESS id 2 len 4
*Mar 1 00:08:54.839: Se0/0 PPP: Sent CDPCP AUTHOR Request
*Mar 1 00:08:54.847: Se0/0 PPP: Sent IPCP AUTHOR Request
*Mar 1 00:08:54.875: Se0/0 CDPCP: Received AAA AUTHOR Response PASS
r0(config-if)#
*Mar 1 00:08:55.827: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0/0, changed state to up
以上是chap的验证过程。
r0(config-if)#do un all
All possible debugging has been turned off
r0(config-if)#
r1(config)#no ip do loo
r1(config)#lin c 0
r1(config-line)#logg s
r1(config-line)#exec-t 00
r1(config-line)#exit
r1(config)#int s0/0
r1(config-if)#ip add 172.16.1.2 255.255.255.0
r1(config-if)#no sh
r1(config-if)#exit
*Mar 1 00:05:48.767: %LINK-3-UPDOWN: Interface Serial0/0, changed state to up
*Mar 1 00:05:49.775: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0/0, changed state to up
r1(config-if)#exit
r1(config)#username r0 pass cisco
r1(config)#int s0/0
r1(config-if)#username r0 pass cisco
r1(config)#int s0/0
r1(config-if)#enc ppp
*Mar 1 00:07:32.291: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0/0, changed state to down
r1(config-if)#ppp authen
r1(config-if)#ppp authentication chap
r1(config-if)#
*Mar 1 00:07:52.351: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0/0, changed state to up
r1(config-if)#do sh ip int b
Interface IP-Address OK? Method Status Protocol
FastEthernet0/0 unassigned YES unset administratively down down
Serial0/0 172.16.1.2 YES manual up up
FastEthernet0/1 unassigned YES unset administratively down down
Serial0/1 unassigned YES unset administratively down down
r1(config-if)#do ping 172.16.1.1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 172.16.1.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/18/48 ms
r1(config-if)#
本文转自gauyanm 51CTO博客，原文链接：http://blog.51cto.com/gauyanm/238163，如需转载请自行联系原作者
