PPP Point to Point Protocol is a Layer 2 WAN Protocol. For
data transmission between any two nodes or routers, a data path
must be established, and flow control procedures must be in place
to ensure deliver of data. Point-to-Point Protocol is a data link
protocol and its basic purpose is to transport layer-3 packets
across a Data Link layer point-to-point network. It is the most
widely used and most popular WAN protocol because it offers
control of data link set-up, dynamic assignment of IP addresses,
network protocol multiplexing, link testing, link configuration,
error detection and negotiation options for network-layer address
and data compression.
PPP
Components
PPP addresses the problems of Internet connectivity by
employing three main components:
A method for encapsulating datagrams over serial links.
PPP uses High-Level Data Link Control (HDLC) as a
basis for encapsulating datagrams over point-to-point
links.
Link Control Protocol (LCP) for setting up,
configuring and testing the data link connection.
PPP uses Network Control Protocol (NCP) for
establishing and configuring different network-layer
protocols. PPP is designed to allow the simultaneous use
of multiple network-layer protocols (e.g., IP, IPX,
Appletalk, ..., etc.)
Authentication
PPP uses two authentication protocols PAP and CHAP. CHAP is
the preferred protocol, because CHAP uses 3-way handshake;
whereas, PAP uses 2-way handshake.
PAP is less secure than CHAP, passwords are sent in clear text
and PAP is only performed upon the initial link set-up. PAP uses
a two-way handshake to establish identity.
ROUTER CONFIGURATION
- Authentication between Data Center Router, Service Center and Shaw
Butte Routers
- Hostname of Data Center Router:
DataCenter
- Hostname of Service Center Router:
ServiceCenter
- Hostname of Shaw Butte Router:
ShawButte
- all three routers need to authenticate each other
