Chapter 3: PPP (Point-to-Point Protocol)
Exam Objectives
Understanding PPP
Seeing the operational flow of PPP
Examining the Link Control Protocol and Network Control Protocol
Revealing PAP and CHAP authentication methods
Understanding PPP configuration using the CLI
Examining the Cisco SDM GUI configuration with PPP
Setting up PAP and CHAP authentication
Monitoring and troubleshooting PPP
What Is PPP?
The Point-to-Point Protocol (PPP) is a standard WAN encapsulation method that transports multiprotocol frames between peer connections across full-duplex, bidirectional links. PPP may be used over dedicated serial point-to-point links, Integrated Services Digital Network (ISDN), or asynchronous dialup connections and has superseded the Serial Line Internet Protocol (SLIP) for synchronous and asynchronous communications
As shown in Figure 3-1, PPP operates at the physical and data link layers of the OSI model to provide data connectivity between endpoints using encapsulation, multiplexing, load balancing, error detection, data compression, and authentication features. Based on the original HDLC specification, PPP adds features such as the Link Control Protocol (LCP) and the Network Control Protocol (NCP). NCP and LCP are key components of PPP and are responsible for proper setup and operation of the Point-to-Point Protocol link between DCE and DTE devices.
Figure 3-1: The OSI model and PPP stack.
Key features of PPP are as follows:
♦ May be used on all DCE and DTE interfaces. ...
