R2#conf t
Enter configuration commands, one per line.  End with CNTL/Z.
R2(config)#default int s2/2
Interface Serial2/2 set to default configuration
R2(config)#
R2(config)#interface Serial2/2
R2(config-if)#
R2(config-if)# ip address 202.100.33.2 255.255.255.0
R2(config-if)#
R2(config-if)# encapsulation ppp
R2(config-if)#
R2(config-if)# ppp authentication pap
R2(config-if)#
R2(config-if)#end
R2#
*Aug 22 17:26:51.895: %SYS-5-CONFIG_I: Configured from console by console
*Aug 22 17:26:52.160: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial2/2, changed state to down
R2#
*Aug 22 17:26:52.163: Se2/2 PPP: Using default call direction
*Aug 22 17:26:52.163: Se2/2 PPP: Treating connection as a dedicated line
*Aug 22 17:26:52.163: Se2/2 PPP: Session handle[25000053] Session id[83]
R2#
*Aug 22 17:27:06.299: Se2/2 PAP: I AUTH-REQ id 1 len 12 from "aaa"
*Aug 22 17:27:06.299: Se2/2 PAP: Authenticating peer aaa
*Aug 22 17:27:06.300: Se2/2 PPP: Sent PAP LOGIN Request
*Aug 22 17:27:06.300: Se2/2 PPP: Received LOGIN Response PASS
*Aug 22 17:27:06.307: Se2/2 PAP: O AUTH-ACK id 1 len 5
*Aug 22 17:27:06.307: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial2/2, changed state to up
R2#
*Aug 22 17:27:06.328: IP ARP: sent rep src 202.100.23.3 aabb.cc00.0211,
                 dst 202.100.23.3 ffff.ffff.ffff Ethernet1/1
R2#sh ip route 202.100.23.3
Routing entry for 202.100.23.3/32
  Known via "connected", distance 0, metric 0 (connected, via interface)
  Routing Descriptor Blocks:
  * directly connected, via Serial2/2
      Route metric is 0, traffic share count is 1
R2#ping 202.100.23.3       
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 202.100.23.3, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 10/22/47 ms
R2#

R3(config)#interface Serial3/3
R3(config-if)#
R3(config-if)# ip address 202.100.23.3 255.255.255.0
R3(config-if)#
R3(config-if)# encapsulation ppp
R3(config-if)#
R3(config-if)# ppp pap sent-username aaa password bbb
R3(config-if)#
R3(config-if)#end
*Aug 22 17:27:06.270: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial3/3, changed state to down
*Aug 22 17:27:06.271: Se3/3 PPP: Using default call direction
*Aug 22 17:27:06.271: Se3/3 PPP: Treating connection as a dedicated line
*Aug 22 17:27:06.271: Se3/3 PPP: Session handle[EC000010] Session id[16]
*Aug 22 17:27:06.296: Se3/3 PPP: No authorization without authentication
*Aug 22 17:27:06.296: Se3/3 PAP: Using hostname from interface PAP
*Aug 22 17:27:06.296: Se3/3 PAP: Using password from interface PAP
*Aug 22 17:27:06.296: Se3/3 PAP: O AUTH-REQ id 1 len 12 from "aaa"
*Aug 22 17:27:06.309: Se3/3 PAP: I AUTH-ACK id 1 len 5
R3(config-if)#end
R3#
*Aug 22 17:27:06.309: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial3/3, changed state to up
R3#
*Aug 22 17:27:07.807: %SYS-5-CONFIG_I: Configured from console by console
R3#

PPP 抓包分析