Weitere ähnliche Inhalte Ähnlich wie Chapter 2 point-to-point protocol (ppp) (20) Chapter 2 point-to-point protocol (ppp)1. Point-to-Point Protocol
(PPP)
Accessing the WAN – Chapter 2
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2. Objectives
Describe the fundamental concepts of point-to-point serial
communication including TDM, demarcation point, DTE-DCE
functions, HDLC encapsulation, and serial interface
troubleshooting.
Describe PPP concepts including PPP layered architecture, PPP
frame structure, PPP session establishment, multiprotocol
encapsulation support, link control protocol (LCP), network
control protocol (NCP), and Internet Protocol Control Protocol
(IPCP).
Configure PPP on a serial interface including enabling PPP
encapsulation, verifying the PPP connection and troubleshooting
encapsulation problems.
Configure PPP authentication including explaining PAP and
CHAP authentication protocols, configuring PPP authentication
using PAP and CHAP, and troubleshooting PPP authentication
problems.
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3. Fundamental Concepts of Point-to-Point
Serial Communication
Concept of serial communication as the basis of WAN
technologies – Which is faster?
Two wires to
carry 2 bits
Eight data-
carrying wires
to carry 8 bits –
1 byte
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4. Serial Communication Standards
Serial connections commonly used – why?
•cost of cable and synchronization
•simpler wiring
•longer than parallel cables
•much less interaction (crosstalk)
There are three key serial communication
standards
•RS-232 - pc to modem
•V.35 - modem-to-multiplexer - DSU
•HSSI - High-Speed Serial Interface – Token
Ring
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6. Fundamental Concepts of Point-to-Point
Serial Communication
Htwo or more data streams are transported across a
single physical connection using TDM
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7. Fundamental Concepts of Point-to-Point
Serial Communication
Define the location of the demarcation point relative to
customer and service provider networks
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8. Fundamental Concepts of Point-to-Point
Serial Communication
Explain the terms DTE and DCE with relative to the
location of devices in a network
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9. Fundamental Concepts of Point-to-Point
Serial Communication
Describe how high-level data link control (HDLC) uses
one of three frame types to encapsulate data
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10. Fundamental Concepts of Point-to-Point
Serial Communication
Explain when and how to configure HDLC
encapsulation on a router
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11. Describe the Fundamental Concepts of
Point-to-Point Serial Communication
Describe the procedure to follow when troubleshooting
a serial connection
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12. Point-to-Point Concepts
Describe PPP in terms of its use in WAN links
•The link quality
management feature
monitors the quality of
the link. If too many
errors are detected, PPP
takes the link down.
•PPP supports PAP and
CHAP authentication.
This feature is explained
and practiced in a later
section.
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13. Point-to-Point Concepts
Describe the general function of each layer of PPP
architecture
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14. Point-to-Point Concepts
Describe the purpose and format of each of the fields in
a PPP frame
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15. Point-to-Point Concepts
Define the three phases of PPP session establishment
LCP must first open the
connection and negotiate
configuration options.
The LCP tests the link to
determine whether the link
quality is sufficient to bring
up network layer protocols.
NCP can separately
configure the network
layer protocols, and
bring them up and take
them down at any
time.
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16. Point-to-Point Concepts
Explain the role of the LCP in PPP
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17. Point-to-Point Concepts
Describe the characteristics of NCP
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18. Configure PPP on a Serial Interface
Describe how configuration options are communicated
in the LCP frame
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19. Configure PPP on a Serial Interface
Explain the purpose of the commands used to
configure and verify PPP connections
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20. Configure PPP on a Serial Interface
Explain the output of the show interfaces serial
command
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21. Configure PPP on a Serial Interface
Explain the output of the debug ppp command
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22. Configuring PPP with Authentication
Differentiate between PAP and CHAP
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23. Configuring PPP with Authentication
Describe how to use PAP to authenticate a PPP
connection
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24. Configuring PPP with Authentication
Describe how to use CHAP to authenticate a PPP
connection
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25. Configuring PPP with Authentication
Outline the PPP encapsulation and authentication
process on a flow chart
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26. Configuring PPP with Authentication
Explain how to configure a PPP connection with
authentication
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27. Configuring PPP with Authentication
Explain the output of the debug ppp authentication
command
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28. Summary
PPP is a widely used WAN protocol
PPP provides multi-protocol LAN to WAN connections
PPP session establishment – 4 phases
Link establishment
Link quality determination
Network layer protocol configuration negotiation
Link termination
WAN Encapsulation
–HDLC default encapsulation
–PPP
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29. Summary
PPP authentication
–PAP
•2 way handshake
–CHAP
•3 way handshake
–Use debug ppp authentication to confirm authentication
configuration
PPP configuration
–Done on a serial interface
After PPP configuration, use show interfaces command
to display:
–LCP state
–NCP state
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30. ITE 1 Chapter 6 © 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 30
Hinweis der Redaktion Graphic 2.1.1.1 Graphics 2.1.2.1, 2.1.2.2 & 2.1.2.3 Graphic 2.1.3.1 Graphics 2.1.4.1 & 2.1.4.2 (for the latter graphic modify it to use the serial and the router to router pictures) Graphic 2.1.5.1 Graphic 2.1.6.1 Graphic 2.1.7.1 (use status) Graphic 2.2.1.1 PPP contains three main components: HDLC protocol for encapsulating datagrams over point-to-point links. Extensible Link Control Protocol (LCP) to establish, configure, and test the data link connection. Family of Network Control Protocols (NCPs) for establishing and configuring different network layer protocols. PPP allows the simultaneous use of multiple network layer protocols. Some of the more common NCPs are Internet Protocol Control Protocol, Appletalk Control Protocol, Novell IPX Control Protocol, Cisco Systems Control Protocol, SNA Control Protocol, and Compression Control Protocol. Graphics 2.2.2.1 thru 2.2. PPP Architecture - Link Control Protocol Layer The LCP is the real working part of PPP. The LCP sits on top of the physical layer and has a role in establishing, configuring, and testing the data-link connection. The LCP establishes the point-to-point link. The LCP also negotiates and sets up control options on the WAN data link, which are handled by the NCPs. 2.3 PPP permits multiple network layer protocols to operate on the same communications link. For every network layer protocol used, PPP uses a separate NCP. For example, IP uses the IP Control Protocol (IPCP), and IPX uses the Novell IPX Control Protocol (IPXCP). Graphic 2.2.3.1 Graphic 2.2.4.1 Graphic 2.2.5.1 (link negotiation) Graphic 2.2.6.1 Graphic 2.3.1.1 Graphic 2.3.2.1 Graphic 2.3.3.1 Graphic 2.3.3.1 (commands) Graphic 2.3.4.1 Graphic 2.4.1.1 Graphic 2.4.2.1 Graphic 2.4.3.1 Graphic 2.4.4.1 Graphic 2.4.5.1 Graphic 2.4.6.1