Point-to-Point Protocol (PPP)
PPP
Point-to-Point Protocol (PPP) is a widely used data link layer protocol in networking, designed for establishing a direct connection between two nodes. PPP operates over both synchronous and asynchronous communication links and is commonly employed in scenarios like dial-up connections over telephone lines. It provides a simple and efficient method for the encapsulation and transmission of data packets over a point-to-point link. PPP supports multiple network layer protocols, allowing it to be versatile in various networking environments. Key features of PPP include error detection through its encapsulation process, support for dynamic IP address assignment through protocols like PPPoE (PPP over Ethernet), and the ability to establish secure connections through authentication mechanisms like PAP (Password Authentication Protocol) and CHAP (Challenge Handshake Authentication Protocol). With its flexibility and reliability, PPP remains a fundamental protocol for establishing point-to-point connections in networking.
Lab:
Disclaimer
This CCIE Routing & Switching Lab Guide is designed to assist candidates in the preparation for Cisco Systems' CCIE Routing & Switching Lab exam. While every effort has been made to ensure that all material is as complete and accurate as possible, the enclosed material is presented on an "as is" basis. Neither the authors nor Forum assume any liability or responsibility to any person or entity with respect to loss or damages incurred from the information contained in this workbook. This workbook was developed by Forum. Any similarities between material presented in this workbook and actual CCIE TM lab material or any other material is completely coincidental.
PPP Multilink Configuration
Configuration:
R1:
hostname R1
!
interface Serial2/0
no ip address
encapsulation ppp
ppp multilink
ppp multilink group 1
no shut
!
interface Serial2/1
no ip address
encapsulation ppp
ppp multilink
ppp multilink group 1
no shut
!
interface Multilink1
ip address 10.0.0.1 255.255.255.252
ppp multilink
ppp multilink group 1
R2:
Hostname R2
!
interface Serial2/0
no ip address
encapsulation ppp
ppp multilink
ppp multilink group 1
no shut
!
interface Serial2/1
no ip address
encapsulation ppp
ppp multilink
ppp multilink group 1
no shut
!
interface Multilink1
ip address 10.0.0.2 255.255.255.252
ppp multilink
ppp multilink group 1
Verification:
R1# Show ppp multilink
Multilink1
Bundle name: R2
Remote Endpoint Discriminator: [1] R2
Local Endpoint Discriminator: [1] R1
Bundle up for 00:01:15, total bandwidth 3088, load 1/255
Receive buffer limit 24000 bytes, frag timeout 1000 ms
0/0 fragments/bytes in reassembly list
0 lost fragments, 0 reordered
0/0 discarded fragments/bytes, 0 lost received
0x14 received sequence, 0x1C sent sequence
Member links: 2 active, 0 inactive (max 255, min not set)
Se2/0, since 00:01:15
Se2/1, since 00:01:15
No inactive multilink interfaces
Verification:
R1#Ping 10.0.0.2
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.0.0.2, timeout is 2 seconds:
! ! ! ! !
Success rate is 100 percent (5/5), round-trip min/avg/max = 124/140/152 ms
Observation:
PPP uses CDPCP network control protocol if CDP is enabled between the two devices PPP uses IPCP network control protocol if IPv4 address is set on the Multilink
PPP Multilink Configuration with PAP Authentication
Configuration:
R1:
hostname R1
!
username R2 password cisco
!
interface Serial 2/0
no ip address
encapsulation ppp
ppp multilink
ppp multilink group 1
no shut
!
interface Serial 2/1
no ip address
encapsulation ppp
ppp multilink
ppp multilink group 1
no shut
!
interface Multilink1
ip address 10.0.0.1 255.255.255.252
ppp authentication pap
ppp pap sent-username R1 password 0 cisco
ppp multilink
ppp multilink group 1
R2:
Hostname R2
!
username R1 password cisco
!
interface Serial2/0
no ip address
encapsulation ppp
ppp multilink
ppp multilink group 1
no shut
!
interface Serial2/1
no ip address
encapsulation ppp
ppp multilink
ppp multilink group 1
no shut
!
interface Multilink1
ip address 10.0.0.2 255.255.255.252
ppp pap sent-username R2 password 0 cisco
ppp multilink
ppp multilink group 1
Verification:
R1# Show ppp multilink
Multilink1
Bundle name: R2
Remote Endpoint Discriminator: [1] R2
Local Endpoint Discriminator: [1] R1
Bundle up for 00:01:15, total bandwidth 3088, load 1/255
Receive buffer limit 24000 bytes, frag timeout 1000 ms
0/0 fragments/bytes in reassembly list
0 lost fragments, 0 reordered
0x14 received sequence, 0x1C sent sequence
Member links: 2 active, 0 inactive (max 255, min not set)
Se2/0, since 00:01:15
Se2/1, since 00:01:15
No inactive multilink interfaces
Verification:
R1#Ping 10.0.0.2
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.0.0.2, timeout is 2 seconds:
! ! ! ! !
Success rate is 100 percent (5/5), round-trip min/avg/max = 124/140/152 ms
PPP Multilink Configuration with CHAP authentication
Configuration:
R1:
hostname R1
!
username R2 password cisco
!
interface Serial 2/0
no ip address
encapsulation ppp
ppp multilink
ppp multilink group 1
no shut
!
interface Serial 2/1
no ip address
encapsulation ppp
ppp multilink
ppp multilink group 1
no shut
!
interface Multilink1
ip address 10.0.0.1 255.255.255.252
ppp authentication chap
ppp multilink
ppp multilink group 1
R2:
Hostname R2
!
username R1 password cisco
!
interface Serial2/0
no ip address
encapsulation ppp
ppp multilink
ppp multilink group 1
no shut
!
interface Serial2/1
no ip address
encapsulation ppp
ppp multilink
ppp multilink group 1
no shut
!
interface Multilink1
ip address 10.0.0.2 255.255.255.252
ppp multilink
ppp multilink group 1
Verification:
R1# Show ppp multilink
Multilink1
Bundle name: R2
Remote Endpoint Discriminator: [1] R2
Local Endpoint Discriminator: [1] R1
Bundle up for 00:01:15, total bandwidth 3088, load 1/255
Receive buffer limit 24000 bytes, frag timeout 1000 ms
0/0 fragments/bytes in reassembly list
0 lost fragments, 0 reordered
0/0 discarded fragments/bytes, 0 lost received
0x14 received sequence, 0x1C sent sequence
Member links: 2 active, 0 inactive (max 255, min not set)
Se2/0, since 00:01:15
Se2/1, since 00:01:15
No inactive multilink interfaces
Verification:
R1#Ping 10.0.0.2
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.0.0.2, timeout is 2 seconds:
! ! ! ! !
Success rate is 100 percent (5/5), round-trip min/avg/max = 124/140/152 ms
debug ppp negotiation
debug ppp authentication
PPP Multilink Configuration with CHAP Callin
Configuration:
R1:
hostname R1
!
username R2 password cisco
!
interface Serial 2/0
no ip address
encapsulation ppp
ppp multilink
ppp multilink group 1
no shut
!
interface Serial 2/1
no ip address
encapsulation ppp
ppp multilink
ppp multilink group 1
no shut
!
interface Multilink1
ip address 10.0.0.1 255.255.255.252
ppp authentication chap callin
ppp multilink
ppp multilink group 1
R2:
hostname R2
!
username R1 password cisco
!
interface Serial2/0
no ip address
encapsulation ppp
ppp multilink
ppp multilink group 1
no shut
!
interface Serial2/1
no ip address
encapsulation ppp
ppp multilink
ppp multilink group 1
no shut
!
interface Multilink1
ip address 10.0.0.2 255.255.255.252
ppp chap hostname R2
ppp chap password 0 cisco
ppp multilink
ppp multilink group 1
Verification:
R1# Show ppp multilink
Multilink1
Bundle name: R2
Remote Endpoint Discriminator: [1] R2
Local Endpoint Discriminator: [1] R1
Bundle up for 00:01:15, total bandwidth 3088, load 1/255
Receive buffer limit 24000 bytes, frag timeout 1000 ms
0/0 fragments/bytes in reassembly list
0 lost fragments, 0 reordered
0/0 discarded fragments/bytes, 0 lost received
0x14 received sequence, 0x1C sent sequence
Member links: 2 active, 0 inactive (max 255, min not set)
Se2/0, since 00:01:15
Se2/1, since 00:01:15
No inactive multilink interfaces
Verification:
R1#Ping 10.0.0.2
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.0.0.2, timeout is 2 seconds:
! ! ! ! !
Success rate is 100 percent (5/5), round-trip min/avg/max = 124/140/152 ms
debug ppp negotiation
debug ppp authentication
PPP Multilink Configuration with PAP Callin
Configuration:
R1:
hostname R1
!
username R2 password cisco
!
interface Serial 2/0
no ip address
encapsulation ppp
ppp multilink
ppp multilink group 1
no shut
!
interface Serial 2/1
no ip address
encapsulation ppp
ppp multilink
ppp multilink group 1
no shut
!
interface Multilink1
ip address 10.0.0.1 255.255.255.252
ppp authentication pap callin
ppp multilink
ppp multilink group 1
R2:
hostname R2
!
username R1 password cisco
!
interface Serial2/0
no ip address
encapsulation ppp
ppp multilink
ppp multilink group 1
no shut
!
interface Serial2/1
no ip address
encapsulation ppp
ppp multilink
ppp multilink group 1
no shut
!
interface Multilink1
ip address 10.0.0.2 255.255.255.252
ppp pap sent-username R2 password 0 cisco
ppp multilink
ppp multilink group 1
Verification:
R1# Show ppp multilink
Multilink1
Bundle name: R2
Remote Endpoint Discriminator: [1] R2
Local Endpoint Discriminator: [1] R1
Bundle up for 00:01:15, total bandwidth 3088, load 1/255
Receive buffer limit 24000 bytes, frag timeout 1000 ms
0/0 fragments/bytes in reassembly list
0 lost fragments, 0 reordered
0/0 discarded fragments/bytes, 0 lost received
0x14 received sequence, 0x1C sent sequence
Member links: 2 active, 0 inactive (max 255, min not set)
Se2/0, since 00:01:15
Se2/1, since 00:01:15
No inactive multilink interfaces
Veriification:
R1#Ping 10.0.0.2
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.0.0.2, timeout is 2 seconds:
! ! ! ! !
Success rate is 100 percent (5/5), round-trip min/avg/max = 124/140/152 ms
debug ppp negotiation
debug ppp authentication
PPP Multilink Configuration with PAP Callin with different username
Configuration:
R1:
hostname R1
!
username hello password cisco
!
interface Serial 2/0
no ip address
encapsulation ppp
ppp multilink
ppp multilink group 1
no shut
!
interface Serial 2/1
no ip address
encapsulation ppp
ppp multilink
ppp multilink group 1
no shut
!
interface Multilink1
ip address 10.0.0.1 255.255.255.252
ppp authentication pap callin
ppp multilink
ppp multilink group 1
R2:
hostname R2
!
username R1 password cisco
!
interface Serial2/0
no ip address
encapsulation ppp
ppp multilink
ppp multilink group 1
no shut
!
interface Serial2/1
no ip address
encapsulation ppp
ppp multilink
ppp multilink group 1
no shut
!
interface Multilink1
ip address 10.0.0.2 255.255.255.252
ppp pap sent-username hello password 0 cisco
ppp multilink
ppp multilink group 1
Verification:
R1# Show ppp multilink
Multilink1
Bundle name: R2
Remote Endpoint Discriminator: [1] R2
Local Endpoint Discriminator: [1] R1
Bundle up for 00:01:15, total bandwidth 3088, load 1/255
Receive buffer limit 24000 bytes, frag timeout 1000 ms
0/0 fragments/bytes in reassembly list
0 lost fragments, 0 reordered
0/0 discarded fragments/bytes, 0 lost received
0x14 received sequence, 0x1C sent sequence
Member links: 2 active, 0 inactive (max 255, min not set)
Se2/0, since 00:01:15
Se2/1, since 00:01:15
No inactive multilink interfaces
Verification:
R1#Ping 10.0.0.2
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.0.0.2, timeout is 2 seconds:
! ! ! ! !
Success rate is 100 percent (5/5), round-trip min/avg/max = 124/140/152 ms
debug ppp negotiation
debug ppp authentication
PPP Multilink Configuration with CHAP Callin with different username
Configuration:
R1:
hostname R1
!
username hello password cisco
!
interface Serial 2/0
no ip address
encapsulation ppp
ppp multilink
ppp multilink group 1
no shut
!
interface Serial 2/1
no ip address
encapsulation ppp
ppp multilink
ppp multilink group 1
no shut
!
interface Multilink1
ip address 10.0.0.1 255.255.255.252
ppp authentication chap callin
ppp multilink
ppp multilink group 1
R2:
hostname R2
!
username R1 password cisco
!
interface Serial2/0
no ip address
encapsulation ppp
ppp multilink
ppp multilink group 1
no shut
!
interface Serial2/1
no ip address
encapsulation ppp
ppp multilink
ppp multilink group 1
no shut
!
interface Multilink1
ip address 10.0.0.2 255.255.255.252
ppp chap hostname hello
ppp chap password 0 cisco
ppp multilink
ppp multilink group 1
Verification:
R1# Show ppp multilink
Multilink1
Bundle name: R2
Remote Endpoint Discriminator: [1] R2
Local Endpoint Discriminator: [1] R1
Bundle up for 00:01:15, total bandwidth 3088, load 1/255
Receive buffer limit 24000 bytes, frag timeout 1000 ms
0/0 fragments/bytes in reassembly list
0 lost fragments, 0 reordered
0/0 discarded fragments/bytes, 0 lost received
0x14 received sequence, 0x1C sent sequence
Member links: 2 active, 0 inactive (max 255, min not set)
Se2/0, since 00:01:15
Se2/1, since 00:01:15
No inactive multilink interfaces
Verification:
R1#Ping 10.0.0.2
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.0.0.2, timeout is 2 seconds:
! ! ! ! !
Success rate is 100 percent (5/5), round-trip min/avg/max = 124/140/152 ms
debug ppp negotiation
debug ppp authentication
PPP Multilink Configuration with IPv6 using PAP Callin
Configuration:
R1:
hostname R1
!
username R2 password cisco
!
interface Serial 2/0
no ip address
encapsulation ppp
ppp multilink
ppp multilink group 1
no shut
!
interface Serial 2/1
no ip address
encapsulation ppp
ppp multilink
ppp multilink group 1
no shut
!
interface Multilink1
ipv6 address 2001:1234:ABCD:1::/64 eui-64
ipv6 enable
ppp authentication pap callin
ppp multilink
ppp multilink group 1
R2:
hostname R2
!
username R1 password cisco
!
interface Serial2/0
no ip address
encapsulation ppp
ppp multilink
ppp multilink group 1
no shut
!
interface Serial2/1
no ip address
encapsulation ppp
ppp multilink
ppp multilink group 1
no shut
!
interface Multilink1
ipv6 address 2001:1234:ABCD:1::/64 eui-64
ipv6 enable
ppp pap sent-username R2 password 0 cisco
ppp multilink
ppp multilink group 1
Verification:
R1# Show ppp multilink
Multilink1
Bundle name: R2
Remote Endpoint Discriminator: [1] R2
Local Endpoint Discriminator: [1] R1
Bundle up for 00:01:15, total bandwidth 3088, load 1/255
Receive buffer limit 24000 bytes, frag timeout 1000 ms
0/0 fragments/bytes in reassembly list
0 lost fragments, 0 reordered
0/0 discarded fragments/bytes, 0 lost received
0x14 received sequence, 0x1C sent sequence
Member links: 2 active, 0 inactive (max 255, min not set)
Se2/0, since 00:01:15
Se2/1, since 00:01:15
No inactive multilink interfaces
Verification:
R1#Ping 10.0.0.2
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.0.0.2, timeout is 2 seconds:
! ! ! ! !
Success rate is 100 percent (5/5), round-trip min/avg/max = 124/140/152 ms
debug ppp negotiation
debug ppp authentication
