ppp配置与分析

目录

1.ppp基础配置

2.pap鉴别配置

3.CHAP鉴别配置

4.IP地址的协商


1.ppp基础配置

注:做完案例记得保存,案例是层层递进的!

以下案例做分析

ppp配置与分析_第1张图片

注意事项

1.路由器配置如下:将2SA拖到上端

 ppp配置与分析_第2张图片

2.连线选择serial,否则最后ping不通

ppp配置与分析_第3张图片

RT-BJ配置如下

sys
Enter system view, return user view with Ctrl+Z.
[Huawei]sysname RT-BJ
[RT-BJ]display interface Serial 4/0/0
Serial4/0/0 current state : UP
Line protocol current state : UP
Last line protocol up time : 2023-09-12 17:21:38 UTC-08:00
Description:HUAWEI, AR Series, Serial4/0/0 Interface
Route Port,The Maximum Transmit Unit is 1500, Hold timer is 10(sec)
Internet protocol processing : disabled
Link layer protocol is PPP
LCP opened
Last physical up time   : 2023-09-12 17:21:36 UTC-08:00
Last physical down time : 2023-09-12 17:21:31 UTC-08:00
Current system time: 2023-09-12 17:22:48-08:00
Physical layer is synchronous, Virtualbaudrate is 64000 bps
Interface is DTE, Cable type is V11, Clock mode is TC
Last 300 seconds input rate 1 bytes/sec 8 bits/sec 0 packets/sec
Last 300 seconds output rate 0 bytes/sec 0 bits/sec 0 packets/sec

Input: 14 packets, 460 bytes
  Broadcast:              0,  Multicast:              0
  Errors:                 0,  Runts:                  0
  Giants:                 0,  CRC:                    0

  Alignments:             0,  Overruns:               0
  Dribbles:               0,  Aborts:                 0
  No Buffers:             0,  Frame Error:            0

这里按任意键可以退出

这里提取出的关键信息

ip地址

disabled

链路协议
Link layer protocol is PPP

LCP,IPCP状态
LCP opened, IPCP 无

Interface is DTE, Cable type is V11, Clock mode is TC

该接口是数据终端设备端(DTE)

使用 V11 电缆进行物理连接

以 Transmit Clock(TC)模式工作。

链路协议 ppp
LCP状态 opened
IPCP状态
物理链路类型 V11
IP地址 disabled
#配置串口Serial 4/0/0串行链路采用ppp
[RT-BJ]interface Serial 4/0/0
[RT-BJ-Serial4/0/0]link-protocol ppp
#配置串口ip地址
[RT-BJ-Serial4/0/0]ip address 192.168.90.2 255.255.255.0
[RT-BJ-Serial4/0/0]qu
#查看所有串口信息
[RT-BJ]display ip interface brief
*down: administratively down
^down: standby
(l): loopback
(s): spoofing
The number of interface that is UP in Physical is 2
The number of interface that is DOWN in Physical is 4
The number of interface that is UP in Protocol is 2
The number of interface that is DOWN in Protocol is 4

Interface                         IP Address/Mask      Physical   Protocol  
GigabitEthernet0/0/0              unassigned           down       down      
GigabitEthernet0/0/1              unassigned           down       down      
GigabitEthernet0/0/2              unassigned           down       down      
NULL0                             unassigned           up         up(s)     
Serial4/0/0                       192.168.90.2/24      up         up        
Serial4/0/1                       unassigned           down       down      

#查看串口状态
[RT-BJ]display interface Serial 4/0/0
Serial4/0/0 current state : UP
Line protocol current state : UP
Last line protocol up time : 2023-09-12 17:21:38 UTC-08:00
Description:HUAWEI, AR Series, Serial4/0/0 Interface
Route Port,The Maximum Transmit Unit is 1500, Hold timer is 10(sec)
Internet Address is 192.168.90.2/24
Link layer protocol is PPP
LCP opened, IPCP stopped
Last physical up time   : 2023-09-12 17:21:36 UTC-08:00
Last physical down time : 2023-09-12 17:21:31 UTC-08:00
Current system time: 2023-09-12 17:33:06-08:00
Physical layer is synchronous, Virtualbaudrate is 64000 bps
Interface is DTE, Cable type is V11, Clock mode is TC
Last 300 seconds input rate 7 bytes/sec 56 bits/sec 0 packets/sec
Last 300 seconds output rate 2 bytes/sec 16 bits/sec 0 packets/sec

Input: 152 packets, 4848 bytes
  Broadcast:              0,  Multicast:              0
  Errors:                 0,  Runts:                  0
  Giants:                 0,  CRC:                    0

  Alignments:             0,  Overruns:               0
  Dribbles:               0,  Aborts:                 0
  No Buffers:             0,  Frame Error:            0
  ---- More ----     

#显示串口当前配置信息
[RT-BJ]display current-configuration interface serial 4/0/0
[V200R003C00]
#
interface Serial4/0/0
 link-protocol ppp
 ip address 192.168.90.2 255.255.255.0 
#
return
[RT-BJ]

 这里提取出的关键信息

ip地址

 ip address 192.168.90.2 255.255.255.0 

链路协议 

link-protocol ppp

LCP,IPCP状态
LCP opened, IPCP stopped

Interface is DTE, Cable type is V11, Clock mode is TC

该接口是数据终端设备端(DTE)

使用 V11 电缆进行物理连接

以 Transmit Clock(TC)模式工作。

链路协议 ppp
LCP状态 opened
IPCP状态 stoped
物理链路类型 V11
IP地址 192.168.90.2 255.255.255.0 

 配置RT-SZ,和RT-BJ相似,这里不做说明

sys
Enter system view, return user view with Ctrl+Z.
[Huawei]sysname RT-SZ
[RT-SZ]display interface Serial 4/0/0
Serial4/0/0 current state : UP
Line protocol current state : UP
Last line protocol up time : 2023-09-12 17:21:38 UTC-08:00
Description:HUAWEI, AR Series, Serial4/0/0 Interface
Route Port,The Maximum Transmit Unit is 1500, Hold timer is 10(sec)
Internet protocol processing : disabled
Link layer protocol is PPP
LCP opened
Last physical up time   : 2023-09-12 17:21:35 UTC-08:00
Last physical down time : 2023-09-12 17:21:33 UTC-08:00
Current system time: 2023-09-12 17:37:13-08:00
Physical layer is synchronous, Virtualbaudrate is 64000 bps
Interface is DTE, Cable type is V11, Clock mode is TC
Last 300 seconds input rate 7 bytes/sec 56 bits/sec 0 packets/sec
Last 300 seconds output rate 2 bytes/sec 16 bits/sec 0 packets/sec

Input: 214 packets, 6912 bytes
  Broadcast:              0,  Multicast:              0
  Errors:                 0,  Runts:                  0
  Giants:                 0,  CRC:                    0

  Alignments:             0,  Overruns:               0
  Dribbles:               0,  Aborts:                 0
  No Buffers:             0,  Frame Error:            0

[RT-SZ]interface 	
[RT-SZ]interface Serial 4/0/0
[RT-SZ-Serial4/0/0]link-protocol ppp
[RT-SZ-Serial4/0/0]ip address 192.168.90.3 255.255.255.0
[RT-SZ-Serial4/0/0]
Sep 12 2023 17:38:05-08:00 RT-SZ %%01IFNET/4/LINK_STATE(l)[0]:The line protocol 
PPP IPCP on the interface Serial4/0/0 has entered the UP state. 
[RT-SZ-Serial4/0/0]qu
[RT-SZ]display ip interface brief
*down: administratively down
^down: standby
(l): loopback
(s): spoofing
The number of interface that is UP in Physical is 2
The number of interface that is DOWN in Physical is 4
The number of interface that is UP in Protocol is 2
The number of interface that is DOWN in Protocol is 4

Interface                         IP Address/Mask      Physical   Protocol  
GigabitEthernet0/0/0              unassigned           down       down      
GigabitEthernet0/0/1              unassigned           down       down      
GigabitEthernet0/0/2              unassigned           down       down      
NULL0                             unassigned           up         up(s)     
Serial4/0/0                       192.168.90.3/24      up         up        
Serial4/0/1                       unassigned           down       down      

[RT-SZ]display interface Serial 4/0/0
Serial4/0/0 current state : UP
Line protocol current state : UP
Last line protocol up time : 2023-09-12 17:38:05 UTC-08:00
Description:HUAWEI, AR Series, Serial4/0/0 Interface
Route Port,The Maximum Transmit Unit is 1500, Hold timer is 10(sec)
Internet Address is 192.168.90.3/24
Link layer protocol is PPP
LCP opened, IPCP opened
Last physical up time   : 2023-09-12 17:21:35 UTC-08:00
Last physical down time : 2023-09-12 17:21:33 UTC-08:00
Current system time: 2023-09-12 17:38:45-08:00
Physical layer is synchronous, Virtualbaudrate is 64000 bps
Interface is DTE, Cable type is V11, Clock mode is TC
Last 300 seconds input rate 7 bytes/sec 56 bits/sec 0 packets/sec
Last 300 seconds output rate 2 bytes/sec 16 bits/sec 0 packets/sec

Input: 235 packets, 7590 bytes
  Broadcast:              0,  Multicast:              0
  Errors:                 0,  Runts:                  0
  Giants:                 0,  CRC:                    0

  Alignments:             0,  Overruns:               0
  Dribbles:               0,  Aborts:                 0
  No Buffers:             0,  Frame Error:            0

[RT-SZ]display current-configuration interface serial 4/0/0
[V200R003C00]
#
interface Serial4/0/0
 link-protocol ppp
 ip address 192.168.90.3 255.255.255.0 
#
return
#到这里IPCP状态为 :opened

关闭串口

[RT-SZ]interface Serial 4/0/0
[RT-SZ-Serial4/0/0]shutdown
Sep 12 2023 17:42:32-08:00 RT-SZ %%01PPP/4/PHYSICALDOWN(l)[1]:On the interface S
erial4/0/0, PPP link was closed because the status of the physical layer was Dow
n. 
[RT-SZ-Serial4/0/0]
[RT-SZ-Serial4/0/0]
Sep 12 2023 17:42:32-08:00 RT-SZ %%01IFNET/4/LINK_STATE(l)[2]:The line protocol 
PPP on the interface Serial4/0/0 has entered the DOWN state. 
[RT-SZ-Serial4/0/0]
Sep 12 2023 17:42:32-08:00 RT-SZ %%01IFNET/4/LINK_STATE(l)[3]:The line protocol 
PPP IPCP on the interface Serial4/0/0 has entered the DOWN state. 
[RT-SZ-Serial4/0/0]
Sep 12 2023 17:42:32-08:00 RT-SZ %%01IFPDT/4/IF_STATE(l)[4]:Interface Serial4/0/
0 has turned into DOWN state.
[RT-SZ-Serial4/0/0]display interface Serial 4/0/0
Serial4/0/0 current state : Administratively DOWN
Line protocol current state : DOWN
Description:HUAWEI, AR Series, Serial4/0/0 Interface
Route Port,The Maximum Transmit Unit is 1500, Hold timer is 10(sec)
Internet Address is 192.168.90.3/24
Link layer protocol is PPP
LCP initial
Last physical up time   : 2023-09-12 17:21:35 UTC-08:00
Last physical down time : 2023-09-12 17:42:32 UTC-08:00
Current system time: 2023-09-12 17:42:44-08:00
Physical layer is synchronous, Virtualbaudrate is 64000 bps
Interface is DTE, Cable type is V11, Clock mode is TC
Last 300 seconds input rate 6 bytes/sec 48 bits/sec 0 packets/sec
Last 300 seconds output rate 2 bytes/sec 16 bits/sec 0 packets/sec

Input: 282 packets, 9090 bytes
  Broadcast:              0,  Multicast:              0
  Errors:                 0,  Runts:                  0
  Giants:                 0,  CRC:                    0

  Alignments:             0,  Overruns:               0
  Dribbles:               0,  Aborts:                 0
  No Buffers:             0,  Frame Error:            0

  ---- More ----

 重新开启串口

[RT-SZ-Serial4/0/0]undo shutdown
[RT-SZ-Serial4/0/0]disp
Sep 12 2023 19:07:42-08:00 RT-SZ %%01IFPDT/4/IF_STATE(l)[5]:Interface Serial4/0/
0 has turned into UP state.
[RT-SZ-Serial4/0/0]display
Sep 12 2023 19:07:45-08:00 RT-SZ %%01IFNET/4/LINK_STATE(l)[6]:The line protocol 
PPP on the interface Serial4/0/0 has entered the UP state. 
[RT-SZ-Serial4/0/0]display 
Sep 12 2023 19:07:45-08:00 RT-SZ %%01IFNET/4/LINK_STATE(l)[7]:The line protocol 
PPP IPCP on the interface Serial4/0/0 has entered the UP state. 
[RT-SZ-Serial4/0/0]display interface Serial 4/0/0
Serial4/0/0 current state : UP
Line protocol current state : UP
Last line protocol up time : 2023-09-12 19:07:45 UTC-08:00
Description:HUAWEI, AR Series, Serial4/0/0 Interface
Route Port,The Maximum Transmit Unit is 1500, Hold timer is 10(sec)
Internet Address is 192.168.90.3/24
Link layer protocol is PPP
LCP opened, IPCP opened
Last physical up time   : 2023-09-12 19:07:42 UTC-08:00
Last physical down time : 2023-09-12 19:06:39 UTC-08:00
Current system time: 2023-09-12 19:07:59-08:00
Physical layer is synchronous, Virtualbaudrate is 64000 bps
Interface is DTE, Cable type is V11, Clock mode is TC
Last 300 seconds input rate 6 bytes/sec 48 bits/sec 0 packets/sec
Last 300 seconds output rate 2 bytes/sec 16 bits/sec 0 packets/sec

Input: 108 packets, 3502 bytes
  Broadcast:              0,  Multicast:              0
  Errors:                 0,  Runts:                  0
  Giants:                 0,  CRC:                    0

  Alignments:             0,  Overruns:               0
  Dribbles:               0,  Aborts:                 0
  No Buffers:             0,  Frame Error:            0

LCP, IPCP的状态

1.没有与对端路由器进行连接时,LCP状态是opened,IPCP状态是无

2.与对端连接,但对端没有配置ppp链路协议时,LCP状态是opened,IPCP状态为stoped

3.当对端配置了ppp链路协议,LCP状态是opened,IPCP的状态是opened

4.如果关闭串口,则LCP状态为:LCP initial

 这里在ping对端路由器,则可以ping通

[RT-SZ-Serial4/0/0]ping 192.168.90.2
  PING 192.168.90.2: 56  data bytes, press CTRL_C to break
    Reply from 192.168.90.2: bytes=56 Sequence=1 ttl=255 time=10 ms
    Reply from 192.168.90.2: bytes=56 Sequence=2 ttl=255 time=20 ms
    Reply from 192.168.90.2: bytes=56 Sequence=3 ttl=255 time=20 ms
    Reply from 192.168.90.2: bytes=56 Sequence=4 ttl=255 time=20 ms
    Reply from 192.168.90.2: bytes=56 Sequence=5 ttl=255 time=20 ms

  --- 192.168.90.2 ping statistics ---
    5 packet(s) transmitted
    5 packet(s) received
    0.00% packet loss
    round-trip min/avg/max = 10/18/20 ms

[RT-BJ]ping 192.168.90.3
  PING 192.168.90.3: 56  data bytes, press CTRL_C to break
    Reply from 192.168.90.3: bytes=56 Sequence=1 ttl=255 time=80 ms
    Reply from 192.168.90.3: bytes=56 Sequence=2 ttl=255 time=40 ms
    Reply from 192.168.90.3: bytes=56 Sequence=3 ttl=255 time=30 ms
    Reply from 192.168.90.3: bytes=56 Sequence=4 ttl=255 time=40 ms
    Reply from 192.168.90.3: bytes=56 Sequence=5 ttl=255 time=30 ms

  --- 192.168.90.3 ping statistics ---
    5 packet(s) transmitted
    5 packet(s) received
    0.00% packet loss
    round-trip min/avg/max = 30/44/80 ms

2.pap鉴别配置

依然是之前的配置

ppp配置与分析_第4张图片

sys
Enter system view, return user view with Ctrl+Z.
#配置串口Serial 4/0/0采用PAP鉴定
[Huawei]interface Serial 4/0/0
[Huawei-Serial4/0/0]ppp authentication-mode pap
[Huawei-Serial4/0/0]qu
[Huawei]sysname RT-BT
#将RT-BJ配置为PAP验证方,aaa是对网络安全的一种管理方式
[RT-BT]AAA
#显示aaa当前本地用户
[RT-BT-aaa]display local-user
  ----------------------------------------------------------------------------
  User-name                      State  AuthMask  AdminLevel  
  ----------------------------------------------------------------------------
  admin                          A      H         -          
  ----------------------------------------------------------------------------
  Total 1 user(s)
#配置被验证方使用的用户名和密码
#用户名为office,密码为12345678,用户名和密码保存在本地
[RT-BT-aaa]local-user myoffice-pap password cipher 12345678
Info: Add a new user.
[RT-BT-aaa]local-user myoffice-pap service-type ppp

#显示aaa当前本地用户
[RT-BT-aaa]display local-user
  ----------------------------------------------------------------------------
  User-name                      State  AuthMask  AdminLevel  
  ----------------------------------------------------------------------------
  admin                          A      H         -          
  myoffice-pap                   A      P         -          
  ----------------------------------------------------------------------------
  Total 2 user(s)
[RT-BT-aaa]qu
#关闭串口Serial 4/0/0 ,再重新打开,使链路重新协商
[RT-BT]interface Serial 4/0/0
[RT-BT-Serial4/0/0]shutdown
Sep 12 2023 22:10:06-08:00 RT-BT %%01PPP/4/PHYSICALDOWN(l)[0]:On the interface S
erial4/0/0, PPP link was closed because the status of the physical layer was Dow
n. 
[RT-BT-Serial4/0/0]
[RT-BT-Serial4/0/0]
Sep 12 2023 22:10:06-08:00 RT-BT %%01IFNET/4/LINK_STATE(l)[1]:The line protocol 
PPP on the interface Serial4/0/0 has entered the DOWN state. 
[RT-BT-Serial4/0/0]
Sep 12 2023 22:10:06-08:00 RT-BT %%01IFPDT/4/IF_STATE(l)[2]:Interface Serial4/0/
0 has turned into DOWN state.
[RT-BT-Serial4/0/0]undo shutdown
[RT-BT-Serial4/0/0]qu
[RT-BT]
Sep 12 2023 22:10:18-08:00 RT-BT %%01IFPDT/4/IF_STATE(l)[3]:Interface Serial4/0/
0 has turned into UP state.
[RT-BT]displa
Sep 12 2023 22:10:21-08:00 RT-BT %%01PPP/4/PEERNOPAP(l)[4]:On the interface Seri
al4/0/0, authentication failed and PPP link was closed because PAP was disabled 
on the peer. 
[RT-BT]displa
Sep 12 2023 22:10:21-08:00 RT-BT %%01PPP/4/RESULTERR(l)[5]:On the interface Seri
al4/0/0, LCP negotiation failed because the result cannot be accepted. 
#查看串口状态
[RT-BT]display interface Serial 4/0/0
Serial4/0/0 current state : UP
Line protocol current state : DOWN
Description:HUAWEI, AR Series, Serial4/0/0 Interface
Route Port,The Maximum Transmit Unit is 1500, Hold timer is 10(sec)
Internet protocol processing : disabled
Link layer protocol is PPP
LCP closed
Last physical up time   : 2023-09-12 22:10:18 UTC-08:00
Last physical down time : 2023-09-12 22:10:06 UTC-08:00
Current system time: 2023-09-12 22:10:33-08:00
Physical layer is synchronous, Virtualbaudrate is 64000 bps
Interface is DTE, Cable type is V11, Clock mode is TC
Last 300 seconds input rate 7 bytes/sec 56 bits/sec 0 packets/sec
Last 300 seconds output rate 2 bytes/sec 16 bits/sec 0 packets/sec

Input: 219 packets, 7104 bytes
  Broadcast:              0,  Multicast:              0
  Errors:                 0,  Runts:                  0
  Giants:                 0,  CRC:                    0

  Alignments:             0,  Overruns:               0
  Dribbles:               0,  Aborts:                 0
  No Buffers:             0,  Frame Error:            0

  ---- More ----

此时RT-BJ 与 RT-SZ互ping不通

因为PAP 是一种用于身份验证的协议,它要求在建立连接时进行用户名和密码的验证。如果只有一个路由器配置了 PAP,而另一个路由器未配置或不支持 PAP 认证,那么当两个路由器之间尝试建立连接时,可能会遇到身份验证失败的问题,从而导致无法正常通信。

[RT-SZ]ping 192.168.90.2
  PING 192.168.90.2: 56  data bytes, press CTRL_C to break
    Request time out
    Request time out
    Request time out
    Request time out
    Request time out

  --- 192.168.90.2 ping statistics ---
    5 packet(s) transmitted
    0 packet(s) received
    100.00% packet loss


[RT-BT]ping 192.168.90.3
  PING 192.168.90.3: 56  data bytes, press CTRL_C to break
    Request time out
    Request time out
    Request time out
    Request time out
    Request time out

  --- 192.168.90.3 ping statistics ---
    5 packet(s) transmitted
    0 packet(s) received
    100.00% packet loss

 将RT-SZ配置为PAP被验证方

#配置PAP认证功能
#配置本端被对端验证时,本端发送的用户名和密码
#验证方和被验证方用户名密码需一致
[RT-SZ]interface Serial 4/0/0
[RT-SZ-Serial4/0/0]ppp pap local-user myoffice-pap password cipher 12345678

#关闭串口Serial 4/0/0 再重新打开,使链路重新协商
[RT-SZ-Serial4/0/0]shutdown
/0 has turned into DOWN state.
[RT-SZ-Serial4/0/0]
[RT-SZ-Serial4/0/0]undo shutdown
[RT-SZ-Serial4/0/0]qu
[RT-SZ]

[RT-SZ]display interface Serial 4/0/0
Serial4/0/0 current state : UP
Line protocol current state : UP
Last line protocol up time : 2023-09-12 23:58:27 UTC-08:00
Description:HUAWEI, AR Series, Serial4/0/0 Interface
Route Port,The Maximum Transmit Unit is 1500, Hold timer is 10(sec)
Internet Address is 192.168.90.3/24
Link layer protocol is PPP
LCP opened, IPCP opened
Last physical up time   : 2023-09-12 23:58:25 UTC-08:00
Last physical down time : 2023-09-12 23:58:19 UTC-08:00
Current system time: 2023-09-13 00:01:22-08:00
Physical layer is synchronous, Virtualbaudrate is 64000 bps
Interface is DTE, Cable type is V11, Clock mode is TC
Last 300 seconds input rate 8 bytes/sec 64 bits/sec 0 packets/sec
Last 300 seconds output rate 4 bytes/sec 32 bits/sec 0 packets/sec

Input: 146 packets, 5944 bytes
  Broadcast:              0,  Multicast:              0
  Errors:                 0,  Runts:                  0
  Giants:                 0,  CRC:                    0

  Alignments:             0,  Overruns:               0
  Dribbles:               0,  Aborts:                 0
  No Buffers:             0,  Frame Error:            0
  ---- More ----

将RT-SZ配置为PAP被验证方后,RT-BJ

[RT-BJ]display interface Serial 4/0/0
Serial4/0/0 current state : UP
Line protocol current state : UP
Last line protocol up time : 2023-09-12 23:58:27 UTC-08:00
Description:HUAWEI, AR Series, Serial4/0/0 Interface
Route Port,The Maximum Transmit Unit is 1500, Hold timer is 10(sec)
Internet Address is 192.168.90.2/24
Link layer protocol is PPP
LCP opened, IPCP opened
Last physical up time   : 2023-09-12 23:58:21 UTC-08:00
Last physical down time : 2023-09-12 23:58:20 UTC-08:00
Current system time: 2023-09-13 00:04:12-08:00
Physical layer is synchronous, Virtualbaudrate is 64000 bps
Interface is DTE, Cable type is V11, Clock mode is TC
Last 300 seconds input rate 6 bytes/sec 48 bits/sec 0 packets/sec
Last 300 seconds output rate 2 bytes/sec 16 bits/sec 0 packets/sec

Input: 185 packets, 7146 bytes
  Broadcast:              0,  Multicast:              0
  Errors:                 0,  Runts:                  0
  Giants:                 0,  CRC:                    0

  Alignments:             0,  Overruns:               0
  Dribbles:               0,  Aborts:                 0
  No Buffers:             0,  Frame Error:            0
  ---- More ----

 现在互ping一下,则可以ping通了

[RT-SZ]ping 192.168.90.2
  PING 192.168.90.2: 56  data bytes, press CTRL_C to break
    Reply from 192.168.90.2: bytes=56 Sequence=1 ttl=255 time=10 ms
    Reply from 192.168.90.2: bytes=56 Sequence=2 ttl=255 time=20 ms
    Reply from 192.168.90.2: bytes=56 Sequence=3 ttl=255 time=10 ms
    Reply from 192.168.90.2: bytes=56 Sequence=4 ttl=255 time=20 ms
    Reply from 192.168.90.2: bytes=56 Sequence=5 ttl=255 time=20 ms

  --- 192.168.90.2 ping statistics ---
    5 packet(s) transmitted
    5 packet(s) received
    0.00% packet loss
    round-trip min/avg/max = 10/16/20 ms



[RT-BJ]ping 192.168.90.3
  PING 192.168.90.3: 56  data bytes, press CTRL_C to break
    Reply from 192.168.90.3: bytes=56 Sequence=1 ttl=255 time=30 ms
    Reply from 192.168.90.3: bytes=56 Sequence=2 ttl=255 time=20 ms
    Reply from 192.168.90.3: bytes=56 Sequence=3 ttl=255 time=20 ms
    Reply from 192.168.90.3: bytes=56 Sequence=4 ttl=255 time=20 ms
    Reply from 192.168.90.3: bytes=56 Sequence=5 ttl=255 time=20 ms

  --- 192.168.90.3 ping statistics ---
    5 packet(s) transmitted
    5 packet(s) received
    0.00% packet loss
    round-trip min/avg/max = 20/22/30 ms

数据抓包

开启路由器RT-BJ串口Serial 4/0/0/的数据抓包,链路类型选择 “PPP”。为了抓取PAP数据包,需要先关闭(使用命令shutdown)路由器 的串口Serial 4/0/0,再重新打开(使用命令undo shutdown)该串口,使链路重新协商。可以抓到3个特殊的包

  1. LCP 配置请求(Configure Request):该数据包由 PPP 客户端发送,用于提出 PPP 配置请求,请求 PPP 服务器协商链路参数。

  2. LCP 配置回应(Configure Ack):该数据包由 PPP 服务器发送,用于确认接收到客户端的 LCP 配置请求,并回复自己的 PPP 配置信息。

  3. LCP 终止请求(Terminate Request):该数据包由 PPP 客户端发送,用于主动终止 PPP 会话。

ppp配置与分析_第5张图片

3.CHAP鉴别配置

注:在完成ppp的基础上进行实验

将RT-BJ配置为CHAP验证方

[RT-BJ]interface Serial 4/0/0
[RT-BJ-Serial4/0/0]link-protocol ppp
[RT-BJ-Serial4/0/0]ip add 192.168.90.2 255.255.255.0
[RT-BJ-Serial4/0/0]q
[RT-BJ]
#配置串口采用CHAP认证功能
[RT-BJ]in Serial 4/0/0
[RT-BJ-Serial4/0/0]ppp authentication-mode chap
#配置本端用户名为rb-bj,密码为niceday
[RT-BJ-Serial4/0/0]ppp chap user rt-bj
[RT-BJ-Serial4/0/0]ppp chap password cipher niceday
[RT-BJ-Serial4/0/0]q
#将RT-BJ配置为验证方
[RT-BJ]aaa
#显示aaa当前本地用户
[RT-BJ-aaa]display local-user
  ----------------------------------------------------------------------------
  User-name                      State  AuthMask  AdminLevel  
  ----------------------------------------------------------------------------
  admin                          A      H         -          
  ----------------------------------------------------------------------------
  Total 1 user(s)
#配置验证方使用的用户名和密码,用户名为myoffice-chap,密码为12345678
#用户名和密码储存在本地
[RT-BJ-aaa]local-user myoffice-chap password cipher 12345678
Info: Add a new user.
[RT-BJ-aaa]local-user myoffice-chap service-type ppp
#显示当前本地用户
[RT-BJ-aaa]display local-user
  ----------------------------------------------------------------------------
  User-name                      State  AuthMask  AdminLevel  
  ----------------------------------------------------------------------------
  admin                          A      H         -          
  myoffice-chap                  A      P         -          
  ----------------------------------------------------------------------------
  Total 2 user(s)
[RT-BJ-aaa]qu
#关闭串口,再重新打开,使链路重新协商
[RT-BJ]interface Serial 4/0/0
[RT-BJ-Serial4/0/0]shutdown
Sep 13 2023 10:23:31-08:00 RT-BJ %%01PPP/4/PHYSICALDOWN(l)[0]:On the interface S
erial4/0/0, PPP link was closed because the status of the physical layer was Dow
n. 
[RT-BJ-Serial4/0/0]
[RT-BJ-Serial4/0/0]
Sep 13 2023 10:23:31-08:00 RT-BJ %%01IFNET/4/LINK_STATE(l)[1]:The line protocol 
PPP on the interface Serial4/0/0 has entered the DOWN state. 
[RT-BJ-Serial4/0/0]
Sep 13 2023 10:23:31-08:00 RT-BJ %%01IFNET/4/LINK_STATE(l)[2]:The line protocol 
PPP IPCP on the interface Serial4/0/0 has entered the DOWN state. 
[RT-BJ-Serial4/0/0]
Sep 13 2023 10:23:31-08:00 RT-BJ %%01IFPDT/4/IF_STATE(l)[3]:Interface Serial4/0/
0 has turned into DOWN state.
[RT-BJ-Serial4/0/0]undo shutdown
[RT-BJ-Serial4/0/0]qu
[RT-BJ]
Sep 13 2023 10:23:39-08:00 RT-BJ %%01IFPDT/4/IF_STATE(l)[4]:Interface Serial4/0/
0 has turned into UP state.
[RT-BJ]
Sep 13 2023 10:23:42-08:00 RT-BJ %%01PPP/4/PEERNOCHAP(l)[5]:On the interface Ser
ial4/0/0, authentication failed and PPP link was closed because CHAP was disable
d on the peer. 
[RT-BJ]
Sep 13 2023 10:23:42-08:00 RT-BJ %%01PPP/4/RESULTERR(l)[6]:On the interface Seri
al4/0/0, LCP negotiation failed because the result cannot be accepted. 

[RT-BJ-Serial4/0/0]display interface Serial 4/0/0
Serial4/0/0 current state : UP
Line protocol current state : DOWN
Description:HUAWEI, AR Series, Serial4/0/0 Interface
Route Port,The Maximum Transmit Unit is 1500, Hold timer is 10(sec)
Internet Address is 192.168.90.2/24
Link layer protocol is PPP
LCP closed
Last physical up time   : 2023-09-13 10:23:39 UTC-08:00
Last physical down time : 2023-09-13 10:23:31 UTC-08:00
Current system time: 2023-09-13 10:26:24-08:00
Physical layer is synchronous, Virtualbaudrate is 64000 bps
Interface is DTE, Cable type is V11, Clock mode is TC
Last 300 seconds input rate 6 bytes/sec 48 bits/sec 0 packets/sec
Last 300 seconds output rate 2 bytes/sec 16 bits/sec 0 packets/sec

Input: 234 packets, 7564 bytes
  Broadcast:              0,  Multicast:              0
  Errors:                 0,  Runts:                  0
  Giants:                 0,  CRC:                    0

  Alignments:             0,  Overruns:               0
  Dribbles:               0,  Aborts:                 0
  No Buffers:             0,  Frame Error:            0


Sep 13 2023 10:26:42-08:00 RT-BJ %%01PPP/4/PEERNOCHAP(l)[17]:On the interface Se
rial4/0/0, authentication failed and PPP link was closed because CHAP was disabl
ed on the peer. 
Sep 13 2023 10:26:42-08:00 RT-BJ %%01PPP/4/RESULTERR(l)[18]:On the interface Ser
ial4/0/0, LCP negotiation failed because the result cannot be accepted. 

在使用 CHAP(Challenge-Handshake Authentication Protocol)进行身份验证时,要实现双向认证,即客户端和服务器之间都需要相互配置 CHAP。所以现在两端是互ping不通的

[RT-BJ-Serial4/0/0]ping 192.168.90.3
  PING 192.168.90.3: 56  data bytes, press CTRL_C to break
    Request time out
    Request time out
Sep 13 2023 10:27:42-08:00 RT-BJ %%01PPP/4/PEERNOCHAP(l)[21]:On the interface Se
rial4/0/0, authentication failed and PPP link was closed because CHAP was disabl
ed on the peer. 
[RT-BJ-Serial4/0/0]
Sep 13 2023 10:27:42-08:00 RT-BJ %%01PPP/4/RESULTERR(l)[22]:On the interface Ser
ial4/0/0, LCP negotiation failed because the result cannot be accepted. 
[RT-BJ-Serial4/0/0]
    Request time out
    Request time out
    Request time out

ping 192.168.90.2
  PING 192.168.90.2: 56  data bytes, press CTRL_C to break
    Request time out
    Request time out
    Request time out
    Request time out
    Request time out

  --- 192.168.90.2 ping statistics ---
    5 packet(s) transmitted
    0 packet(s) received
    100.00% packet loss

现在将RT-SZ也配置为CHAP被验证方

[RT-SZ]interface Serial 4/0/0
#配置本端被对端验证时,本端发送的用户名和密码、
#用户名和密码需与验证方一致
[RT-SZ-Serial4/0/0]ppp chap user myoffice-chap
[RT-SZ-Serial4/0/0]ppp chap password cipher 12345678
[RT-SZ-Serial4/0/0]shutdown
Sep 13 2023 10:34:21-08:00 RT-SZ %%01PPP/4/PHYSICALDOWN(l)[12]:On the interface 
Serial4/0/0, PPP link was closed because the status of the physical layer was Do
wn. 
[RT-SZ-Serial4/0/0]
Sep 13 2023 10:34:21-08:00 RT-SZ %%01IFPDT/4/IF_STATE(l)[15]:Interface Serial4/0
/0 has turned into DOWN state.
[RT-SZ-Serial4/0/0]display interface Serial 4/0/0
Serial4/0/0 current state : Administratively DOWN
Line protocol current state : DOWN
Description:HUAWEI, AR Series, Serial4/0/0 Interface
Route Port,The Maximum Transmit Unit is 1500, Hold timer is 10(sec)
Internet Address is 192.168.90.3/24
Link layer protocol is PPP
LCP initial
Last physical up time   : 2023-09-13 10:23:38 UTC-08:00
Last physical down time : 2023-09-13 10:34:21 UTC-08:00
Current system time: 2023-09-13 10:34:43-08:00
Physical layer is synchronous, Virtualbaudrate is 64000 bps
Interface is DTE, Cable type is V11, Clock mode is TC
Last 300 seconds input rate 5 bytes/sec 40 bits/sec 0 packets/sec
Last 300 seconds output rate 2 bytes/sec 16 bits/sec 0 packets/sec

Input: 294 packets, 9875 bytes
  Broadcast:              0,  Multicast:              0
  Errors:                 0,  Runts:                  0
  Giants:                 0,  CRC:                    0

  Alignments:             0,  Overruns:               0
  Dribbles:               0,  Aborts:                 0
  No Buffers:             0,  Frame Error:            0

 重新打开串口Serial 4/0/0 ,使链路重新协商

[RT-SZ-Serial4/0/0]undo shutdown
[RT-SZ-Serial4/0/0]qu
[RT-SZ]
Sep 13 2023 10:38:21-08:00 RT-SZ %%01IFPDT/4/IF_STATE(l)[16]:Interface Serial4/0
/0 has turned into UP state.
[RT-SZ]
Sep 13 2023 10:38:23-08:00 RT-SZ %%01IFNET/4/LINK_STATE(l)[17]:The line protocol
 PPP on the interface Serial4/0/0 has entered the UP state. 
[RT-SZ]
Sep 13 2023 10:38:23-08:00 RT-SZ %%01IFNET/4/LINK_STATE(l)[18]:The line protocol
 PPP IPCP on the interface Serial4/0/0 has entered the UP state. 

[RT-SZ]display interface Serial 4/0/0
Serial4/0/0 current state : UP
Line protocol current state : UP
Last line protocol up time : 2023-09-13 10:38:23 UTC-08:00
Description:HUAWEI, AR Series, Serial4/0/0 Interface
Route Port,The Maximum Transmit Unit is 1500, Hold timer is 10(sec)
Internet Address is 192.168.90.3/24
Link layer protocol is PPP
LCP opened, IPCP opened
Last physical up time   : 2023-09-13 10:38:21 UTC-08:00
Last physical down time : 2023-09-13 10:34:21 UTC-08:00
Current system time: 2023-09-13 10:39:14-08:00
Physical layer is synchronous, Virtualbaudrate is 64000 bps
Interface is DTE, Cable type is V11, Clock mode is TC
Last 300 seconds input rate 2 bytes/sec 16 bits/sec 0 packets/sec
Last 300 seconds output rate 1 bytes/sec 8 bits/sec 0 packets/sec

Input: 311 packets, 10482 bytes
  Broadcast:              0,  Multicast:              0
  Errors:                 0,  Runts:                  0
  Giants:                 0,  CRC:                    0

  Alignments:             0,  Overruns:               0
  Dribbles:               0,  Aborts:                 0
  No Buffers:             0,  Frame Error:            0
  ---- More ----

现在两端可以互ping

[RT-SZ]ping 192.168.90.2
  PING 192.168.90.2: 56  data bytes, press CTRL_C to break
    Reply from 192.168.90.2: bytes=56 Sequence=1 ttl=255 time=100 ms
    Reply from 192.168.90.2: bytes=56 Sequence=2 ttl=255 time=20 ms
    Reply from 192.168.90.2: bytes=56 Sequence=3 ttl=255 time=20 ms
    Reply from 192.168.90.2: bytes=56 Sequence=4 ttl=255 time=20 ms
    Reply from 192.168.90.2: bytes=56 Sequence=5 ttl=255 time=20 ms

  --- 192.168.90.2 ping statistics ---
    5 packet(s) transmitted
    5 packet(s) received
    0.00% packet loss
    round-trip min/avg/max = 20/36/100 ms


sys
Enter system view, return user view with Ctrl+Z.
[RT-BJ]ping 192.168.90.3
  PING 192.168.90.3: 56  data bytes, press CTRL_C to break
    Reply from 192.168.90.3: bytes=56 Sequence=1 ttl=255 time=30 ms
    Reply from 192.168.90.3: bytes=56 Sequence=2 ttl=255 time=20 ms
    Reply from 192.168.90.3: bytes=56 Sequence=3 ttl=255 time=20 ms
    Reply from 192.168.90.3: bytes=56 Sequence=4 ttl=255 time=30 ms
    Reply from 192.168.90.3: bytes=56 Sequence=5 ttl=255 time=20 ms

  --- 192.168.90.3 ping statistics ---
    5 packet(s) transmitted
    5 packet(s) received
    0.00% packet loss
    round-trip min/avg/max = 20/24/30 ms

 现在进行数据抓包

先关闭路由器的串口Serial 4/0/0,再重新打开 该串口,使链路重新协商

chap抓到的需要注意的包

  1. Challenge 报文:服务器向客户端发送 Challenge 报文,其中包含一个随机数作为挑战。客户端需要使用自己的密码和该挑战进行计算,生成响应报文。

  2. Response 报文:客户端收到 Challenge 报文后,使用自己的密码和挑战进行计算,生成 Response 报文。该报文包括了客户端的身份信息以及一个通过 HMAC(Hash-based Message Authentication Code)算法计算的消息摘要值。

  3. Success 报文:服务器接收到客户端发送的 Response 报文后,使用相同的算法和密码对挑战进行计算,并将结果与客户端发送的消息摘要进行比对。如果两者一致,服务器会发送 Success 报文给客户端,表示认证成功。

  4. Failure 报文:如果在认证过程中出现错误或认证失败,服务器会发送 Failure 报文,通知客户端认证失败。

ppp配置与分析_第6张图片

注:如果抓不到包可能的原因

多耐心等会儿

  1. 未启用 CHAP:确保在链路重新协商之前已正确启用了 CHAP。双方必须都配置了 CHAP,并且在链路建立之前进行了正确的身份验证设置。

  2. 认证失败:如果链路重新协商后仍无法捕获到 CHAP 报文,可能是因为认证过程中出现了错误或认证失败。这可能是由于密码不正确、身份信息不匹配等原因导致的。需要确认配置信息是否正确,并检查认证失败的原因。

  3. 数据包丢失:有时,在网络中的某些节点或设备上,数据包可能会丢失或被屏蔽,从而导致无法捕获到特殊的 CHAP 报文。可能需要通过调试和排除法来确定是否存在数据包丢失的情况。

  4. 加密和隧道技术:如果 CHAP 通信是通过加密的隧道或虚拟专用网络(VPN)进行的,Wireshark 在抓取数据包时可能无法读取加密的内容。在这种情况下,Wireshark 可能无法直接解密和显示 CHAP 报文。

4.IP地址的协商

ip address ppp-negotiate

  1. PPP 协商地址:在 PPP 连接建立过程中,双方之间的 PPP 协议会协商分配 IP 地址。如果启用了 "ip address ppp-negotiate" 命令,在 PPP 连接建立时,设备将发送请求来获取可用的 IP 地址。

  2. 动态 IP 地址分配:一旦 PPP 连接成功并且对方设备同意提供 IP 地址,本地设备将被分配一个动态 IP 地址。这个地址通常由对端设备或服务器分配,并且每次建立 PPP 连接时都可能有所不同。

 在完成路由器PPP,CHAP的配置基础上

(1)配置路由器RT-BJ

sys
Enter system view, return user view with Ctrl+Z.
#创建全局地址池,用于为被验证方分配地址
[RT-BJ]ip pool 1
#配置全局地址池下可分配的网段地址
Info: It's successful to create an IP address pool.
[RT-BJ-ip-pool-1]network 192.168.90.0 mask 255.255.255.0
[RT-BJ-ip-pool-1]qu
#配置串口Serial 4/0/0,为被验证方从指定地址池分配ip地址
[RT-BJ]interface Serial 4/0/0
[RT-BJ-Serial4/0/0]remote add pool 1
#也可以为被验证方分配ip地址
[RT-BJ-Serial4/0/0]remote add 192.168.90.8
#关闭串口再重新打开,使得链路重新协商
[RT-BJ-Serial4/0/0]shutdown
Sep 13 2023 10:52:36-08:00 RT-BJ %%01PPP/4/PHYSICALDOWN(l)[0]:On the interface S
erial4/0/0, PPP link was closed because the status of the physical layer was Dow
n. 
[RT-BJ-Serial4/0/0]
Sep 13 2023 10:52:36-08:00 RT-BJ %%01IFNET/4/LINK_STATE(l)[1]:The line protocol 
PPP on the interface Serial4/0/0 has entered the DOWN state. 
[RT-BJ-Serial4/0/0]
Sep 13 2023 10:52:36-08:00 RT-BJ %%01IFNET/4/LINK_STATE(l)[2]:The line protocol 
PPP IPCP on the interface Serial4/0/0 has entered the DOWN state. 
[RT-BJ-Serial4/0/0]
Sep 13 2023 10:52:36-08:00 RT-BJ %%01IFPDT/4/IF_STATE(l)[3]:Interface Serial4/0/
0 has turned into DOWN state.
[RT-BJ-Serial4/0/0]undo shutdown
[RT-BJ-Serial4/0/0]
Sep 13 2023 10:52:45-08:00 RT-BJ %%01IFPDT/4/IF_STATE(l)[4]:Interface Serial4/0/
0 has turned into UP state.
[RT-BJ-Serial4/0/0]qu
[RT-BJ]
Sep 13 2023 10:52:47-08:00 RT-BJ %%01IFNET/4/LINK_STATE(l)[5]:The line protocol 
PPP on the interface Serial4/0/0 has entered the UP state. 
[RT-BJ]
Sep 13 2023 10:52:47-08:00 RT-BJ %%01IFNET/4/LINK_STATE(l)[6]:The line protocol 
PPP IPCP on the interface Serial4/0/0 has entered the UP state. 
#查看串口状态
[RT-BJ]display interface Serial 4/0/0
Serial4/0/0 current state : UP
Line protocol current state : UP
Last line protocol up time : 2023-09-13 10:52:47 UTC-08:00
Description:HUAWEI, AR Series, Serial4/0/0 Interface
Route Port,The Maximum Transmit Unit is 1500, Hold timer is 10(sec)
Internet Address is 192.168.90.2/24
Link layer protocol is PPP
LCP opened, IPCP opened
Last physical up time   : 2023-09-13 10:52:45 UTC-08:00
Last physical down time : 2023-09-13 10:52:36 UTC-08:00
Current system time: 2023-09-13 10:53:02-08:00
Physical layer is synchronous, Virtualbaudrate is 64000 bps
Interface is DTE, Cable type is V11, Clock mode is TC
Last 300 seconds input rate 6 bytes/sec 48 bits/sec 0 packets/sec
Last 300 seconds output rate 2 bytes/sec 16 bits/sec 0 packets/sec

Input: 508 packets, 17441 bytes
  Broadcast:              0,  Multicast:              0
  Errors:                 0,  Runts:                  0
  Giants:                 0,  CRC:                    0

  Alignments:             0,  Overruns:               0
  Dribbles:               0,  Aborts:                 0
  No Buffers:             0,  Frame Error:            0

[RT-BJ]

  Please check whether system data has been changed, and save data in time

  Configuration console time out, please press any key to log on

(2)配置路由器RT-SZ

sys
Enter system view, return user view with Ctrl+Z.
#配置串口Serial 4/0/0通过地址协商从验证方分配ip地址
[RT-SZ]interface Serial 4/0/0
[RT-SZ-Serial4/0/0]ip add ppp-negotiate
Sep 13 2023 11:07:22-08:00 RT-SZ %%01IFNET/4/LINK_STATE(l)[0]:The line protocol 
PPP IPCP on the interface Serial4/0/0 has entered the DOWN state. 
[RT-SZ-Serial4/0/0]qu
[RT-SZ]display 
Sep 13 2023 11:07:28-08:00 RT-SZ %%01IFNET/4/LINK_STATE(l)[1]:The line protocol 
PPP IPCP on the interface Serial4/0/0 has entered the UP state. 
[RT-SZ]display interface Serial 4/0/0
Serial4/0/0 current state : UP
Line protocol current state : UP
Last line protocol up time : 2023-09-13 11:07:28 UTC-08:00
Description:HUAWEI, AR Series, Serial4/0/0 Interface
Route Port,The Maximum Transmit Unit is 1500, Hold timer is 10(sec)
Internet Address is negotiated, 192.168.90.8/32
Link layer protocol is PPP
LCP opened, IPCP opened
Last physical up time   : 2023-09-13 10:52:44 UTC-08:00
Last physical down time : 2023-09-13 10:52:42 UTC-08:00
Current system time: 2023-09-13 11:07:36-08:00
Physical layer is synchronous, Virtualbaudrate is 64000 bps
Interface is DTE, Cable type is V11, Clock mode is TC
Last 300 seconds input rate 6 bytes/sec 48 bits/sec 0 packets/sec
Last 300 seconds output rate 2 bytes/sec 16 bits/sec 0 packets/sec

Input: 669 packets, 22804 bytes
  Broadcast:              0,  Multicast:              0
  Errors:                 0,  Runts:                  0
  Giants:                 0,  CRC:                    0

  Alignments:             0,  Overruns:               0
  Dribbles:               0,  Aborts:                 0
  No Buffers:             0,  Frame Error:            0
  ---- More ----

[RT-SZ]interface serial 4/0/0
#关闭串口再重新打开,使链路重新协商
[RT-SZ-Serial4/0/0]shutdown
Sep 13 2023 11:10:08-08:00 RT-SZ %%01PPP/4/PHYSICALDOWN(l)[2]:On the interface S
erial4/0/0, PPP link was closed because the status of the physical layer was Dow
n. 
[RT-SZ-Serial4/0/0]
[RT-SZ-Serial4/0/0]
Sep 13 2023 11:10:08-08:00 RT-SZ %%01IFNET/4/LINK_STATE(l)[3]:The line protocol 
PPP on the interface Serial4/0/0 has entered the DOWN state. 
[RT-SZ-Serial4/0/0]
Sep 13 2023 11:10:08-08:00 RT-SZ %%01IFNET/4/LINK_STATE(l)[4]:The line protocol 
PPP IPCP on the interface Serial4/0/0 has entered the DOWN state. 
[RT-SZ-Serial4/0/0]
Sep 13 2023 11:10:08-08:00 RT-SZ %%01IFPDT/4/IF_STATE(l)[5]:Interface Serial4/0/
0 has turned into DOWN state.
[RT-SZ-Serial4/0/0]undo shutdown
[RT-SZ-Serial4/0/0]
Sep 13 2023 11:10:13-08:00 RT-SZ %%01IFPDT/4/IF_STATE(l)[6]:Interface Serial4/0/
0 has turned into UP state.
[RT-SZ-Serial4/0/0]
Sep 13 2023 11:10:13-08:00 RT-SZ %%01IFNET/4/LINK_STATE(l)[7]:The line protocol 
PPP on the interface Serial4/0/0 has entered the UP state. 
[RT-SZ-Serial4/0/0]
Sep 13 2023 11:10:13-08:00 RT-SZ %%01IFNET/4/LINK_STATE(l)[8]:The line protocol 
PPP IPCP on the interface Serial4/0/0 has entered the UP state. 
[RT-SZ-Serial4/0/0]qu

(3)两端互ping

[RT-SZ]ping 192.168.90.2
  PING 192.168.90.2: 56  data bytes, press CTRL_C to break
    Reply from 192.168.90.2: bytes=56 Sequence=1 ttl=255 time=20 ms
    Reply from 192.168.90.2: bytes=56 Sequence=2 ttl=255 time=20 ms
    Reply from 192.168.90.2: bytes=56 Sequence=3 ttl=255 time=20 ms
    Reply from 192.168.90.2: bytes=56 Sequence=4 ttl=255 time=30 ms
    Reply from 192.168.90.2: bytes=56 Sequence=5 ttl=255 time=30 ms

  --- 192.168.90.2 ping statistics ---
    5 packet(s) transmitted
    5 packet(s) received
    0.00% packet loss
    round-trip min/avg/max = 20/24/30 ms


[RT-BJ]ping 192.168.90.8
  PING 192.168.90.8: 56  data bytes, press CTRL_C to break
    Reply from 192.168.90.8: bytes=56 Sequence=1 ttl=255 time=40 ms
    Reply from 192.168.90.8: bytes=56 Sequence=2 ttl=255 time=30 ms
    Reply from 192.168.90.8: bytes=56 Sequence=3 ttl=255 time=20 ms
    Reply from 192.168.90.8: bytes=56 Sequence=4 ttl=255 time=20 ms
    Reply from 192.168.90.8: bytes=56 Sequence=5 ttl=255 time=20 ms

  --- 192.168.90.8 ping statistics ---
    5 packet(s) transmitted
    5 packet(s) received
    0.00% packet loss
    round-trip min/avg/max = 20/26/40 ms

(4)数据抓包

ppp配置与分析_第7张图片

在PPP建立连接后,通过LCP(Link Control Protocol)完成链路的建立和配置。随后,双方会使用NCP(网络控制协议)来为对端分配IP地址,具体工作流程如下:

ppp配置与分析_第8张图片 

当PPP连接建立后,通信节点会通过发送IPCP报文来交换协商信息,并最终决定分配给本地设备的IP地址。 

  1. 协商阶段:双方节点交互发送IPCP报文,包含各自的IP地址请求和IP配置选项。可以使用"Configure-Request"、"Configure-Ack"等消息类型进行交流。

  2. 协商参数:双方节点根据接收到的IPCP报文,协商并确定IP地址、网络掩码、默认网关等参数。

  3. IP地址分配:根据协商结果,对端会向本地设备分配一个有效的IP地址。

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