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)