(6) PPP Implementation


ServiceCenter Router - PPP Configuration


Router(config)#username name password secret
Router (config)#encapsulation ppp
Router(config)#ppp authentication chap

(If PAP is selected then):
Router(config)#ppp pap sent-username username password password

(If CHAP is selected then):
* Router(config)#ppp chap hostname hostname
* Router(config)#ppp chap password secret

Note: The other two regional Hub routers will be set up the same way

PPP Implementation

Point-to-Point Protocol (PPP) makes use of two important protocols for it's operations. Link Control Protocol (LCP) is responsible for establishing, checking and terminating the link between the destination and the source. The Network Control Protocol (NCP) is used to provide support for many different network layer protocols, including TCP/IP and Novell IPX, the two protocols being used in the Washington District School WAN.

PPP can be used on different types of routers, with no interaction difficulties between brands, and supports two forms of authentication: Password Authentication Protocol (PAP) and Challenge Handshake Authentication Protocol (CHAP). PAP is the less secure of these, passing user-names and passwords only once in clear-text format. CHAP issues a challenge at login, and at random times during the session, requiring authentication each time.


PPP Implementation Location

PPP will be implemented across the WAN on all router ports with the exception of the Internet connection, which will use Frame relay for it's layer 2 protocol. PPP is the standard for serial line encapsulation, so it is the most logical choice for the Washington District WAN.

In order to check that PPP is functioning correctly, and to check that LCP and NCP are running, we will use the command

Router(config)# show interfaces S1