Point To Point Protocol

Point-to-Point Protocol (PPP) is a data link layer (layer 2) communication protocol between two routers directly without any host or any other networking in between. It can provide connection authentication, transmission encryption, and data compression.

Configuring CHAP

For this configuration imagine that you have a pair of networks with a router and a host connected via a serial connection. For this configuration we will be securing a serial connection between the two routers using point to point running on interfaces s0/0/0. For this instance we will be using the CHAP variation

R1

R1(config)# username R1 password password

this sets up a local user database entry for the “R1” router with a password of “password”

R1(config)# interface s0/0/0
R1(config-if)# encapsulation ppp
R1(config-if)# ppp authentication chap

R2

R2(config)# username R2 password password

this sets up a local user database entry for the “R2” router with a password of “password”

R2(config)# interface s0/0/0
R2(config-if)# encapsulation ppp
R2(config-if)# ppp authentication chap

Configuring PAP

For this configuration imagine that you have a pair of networks with a router and a host connected via a serial connection. For this configuration we will be securing a serial connection between the two routers using point to point running on interfaces s0/0/0. For this instance we will be using the PAP variation

R1

R1(config)# username R1 password password

this sets up a local user database entry for the “R1” router with a password of “password”

R1(config)# interface s0/0/0
R1(config-if)# encapsulation ppp
R1(config-if)# ppp authentication pap
R1(config-if)# ppp pap sent-username R1 password password

R2

R2(config)# username R2 password password

this sets up a local user database entry for the “R2” router with a password of “password”

R2(config)# interface s0/0/0
R2(config-if)# encapsulation ppp
R2(config-if)# ppp authentication pap
R2(config-if)# ppp pap sent-username R2 password password