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
注意事项
1.路由器配置如下：将2SA拖到上端
2.连线选择serial，否则最后ping不通
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 PPPLCP，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 | 无 |
| 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 stoppedInterface 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
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
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。
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。
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。
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
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。
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。
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。
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。
注：如果抓不到包可能的原因
多耐心等会儿
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。
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。
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。
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
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。
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
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：
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。
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。
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。
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。