PPP protocol configuration and PAP authentication Configuration

Through understanding the PPP protocol, we also entered the configuration phase. We know that the PPP protocol (point to point protocol) is the predecessor of the point-to-point protocol, SLIP, the PPP protocol provides a standard method for encapsulating multiple network data packets on point-to-point links. Now we will focus on the configuration of PPP protocol and PAP authentication.

Advantages of PPP over SLIP protocols:

1. Support synchronous and asynchronous serial links;

2. Supports multiple network protocols;

3. support negotiation of various connection parameters;

4. Supports error detection;

5. User authentication is supported;

6. Data Compression is allowed.

Composition of the PPP protocol:

1. protocol encapsulation

2. LCP

3. NCP

PPP operation process:

1. Link unavailable stage

2. link establishment phase

3. Authentication phase

4. Network Layer Protocol phase

5. End of the link

LCP protocol negotiation:

MRU maximum data unit/Magic Number Magic word/authentication method/link Compression

NCP protocol negotiation:

IP address; TCP/IP Header Compression

Authentication method:

PAP/CHAP

PPP protocol Configuration:

Encapsulate PPP:

 
 

  
  
Router(config)#inter serial 2/0  
  
  
Router(config-if)#encapsulation ppp 
 
 

Set the clock frequency on the DCE side:

 
 

  
  
Router(config-if)#clock rate 64000 
 
 

Interface IP Configuration:

 
 

  
  
Router(config-if)#ip address 192.168.10.1 255.255.255.0  
  
  
Router(config-if)#no shutdown 
 
 

PAP authentication Configuration:

PAP authentication configuration, Master authentication end:

 
 

  
  
Router(config-if)#exit  
  
  
Router(config)#username derek password 0 123  
  
  
Router(config)#inter s2/0  
  
  
Router(config-if)#ppp authentication   
  
  
%SYS-5-CONFIG_I: Configured from console by console 
 
 

PAP authentication configuration, authenticated end:

 
 

  
  
Router(config-if)#ppp pap sent-username derek password 0 123 
 
 

PAP authentication configuration complete, test:

 
 

  
  
Router#ping 192.168.10.2  
  
  
Router#debug ppp packet 
 
 

View Port:

 
 

  
  
Router#show interfaces s 2/0  
  
  
Serial2/0 is up, line protocol is up (connected)  
  
  
Hardware is HD64570  
  
  
Internet address is 192.168.10.2/24  
  
  
MTU 1500 bytes, BW 128 Kbit, DLY 20000 usec, rely 255/255, load 1/255  
  
  
Encapsulation PPP, loopback not set, keepalive set (10 sec)  
  
  
LCP Open  
  
  
Open: IPCP, CDPCP  
  
  
Last input never, output never, output hang never  
  
  
Last clearing of "show interface" counters never  
  
  
Input queue: 0/75/0 (size/max/drops); Total output drops: 0  
  
  
Queueing strategy: weighted fair  
  
  
Output queue: 0/1000/64/0 (size/max total/threshold/drops)