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Chapter14ccna

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Chapter14ccna

  1. 1. Instructor & Todd Lammle Sybex CCNA 640-802 Chapter 14: Wide Area Networks
  2. 2. Chapter 14 Objectives <ul><li>The CCNA Topics Covered in this chapter include: </li></ul><ul><li>Introduction to WAN’s </li></ul><ul><li>HDLC </li></ul><ul><li>PPP </li></ul><ul><li>Frame Relay </li></ul><ul><li>Introduction to VPN’s </li></ul>
  3. 3. Defining WAN Terms <ul><li>Customer Premises Equipment (CPE) </li></ul><ul><li>Demarcation (demarc) </li></ul><ul><li>Local loop </li></ul><ul><li>Central Office (CO) </li></ul><ul><li>Toll network </li></ul>
  4. 4. WAN Connection Types
  5. 5. DTE-DCE-DTE
  6. 6. WAN Support <ul><li>Frame Relay </li></ul><ul><li>ISDN </li></ul><ul><li>LAPB </li></ul><ul><li>LAPD </li></ul><ul><li>HDLC </li></ul><ul><li>PPP </li></ul><ul><li>ATM </li></ul>
  7. 7. HDLC Protocol <ul><li>Bit-oriented Data Link layer ISO standard protocol </li></ul><ul><li>Specifies a data encapsulation method </li></ul><ul><li>No authentication can be used </li></ul>
  8. 8. HDLC Frame Format
  9. 9. Point-to-Point Protocol (PPP) <ul><li>Purpose: </li></ul><ul><ul><li>Transport layer-3 packets across a Data Link layer point-to-point link </li></ul></ul><ul><li>Can be used over asynchronous serial (dial-up) or synchronous serial (ISDN) media </li></ul><ul><ul><li>Uses Link Control Protocol (LCP) </li></ul></ul><ul><ul><ul><li>Builds & maintains data-link connections </li></ul></ul></ul>
  10. 10. Point-to-Point Protocol Stack
  11. 11. PPP Main Components <ul><li>EIA/TIA-232-C </li></ul><ul><ul><li>Intl. Std. for serial communications </li></ul></ul><ul><li>HDLC </li></ul><ul><ul><li>Serial link datagram encapsulation method </li></ul></ul><ul><li>LCP </li></ul><ul><ul><li>Used in P-t-P connections: </li></ul></ul><ul><ul><ul><li>Establishing </li></ul></ul></ul><ul><ul><ul><li>Maintaining </li></ul></ul></ul><ul><ul><ul><li>Terminating </li></ul></ul></ul><ul><li>NCP </li></ul><ul><ul><li>Method of establishing & configuring Network Layer protocols </li></ul></ul><ul><ul><li>Allows simultaneous use of multiple Network layer protocols </li></ul></ul>
  12. 12. LCP Configuration Options <ul><li>Authentication </li></ul><ul><ul><li>PAP </li></ul></ul><ul><ul><li>CHAP </li></ul></ul><ul><li>Compression </li></ul><ul><ul><li>Stacker </li></ul></ul><ul><ul><li>Predictor </li></ul></ul><ul><li>Error detection </li></ul><ul><ul><li>Quality </li></ul></ul><ul><ul><li>Magic Number </li></ul></ul><ul><li>Multilink </li></ul><ul><ul><li>Splits the load for PPP over 2+ parallel circuits; a bundle </li></ul></ul>
  13. 13. PPP Session Establishment <ul><li>Link-establishment phase </li></ul><ul><li>Authentication phase </li></ul><ul><li>Network-layer protocol phase </li></ul>
  14. 14. PPP Session Establishment
  15. 15. PPP Authentication Methods <ul><li>Password Authentication Protocol (PAP) </li></ul><ul><ul><li>Passwords sent in clear text </li></ul></ul><ul><ul><li>Remote node returns username & password </li></ul></ul><ul><li>Challenge Authentication Protocol (CHAP) </li></ul><ul><ul><li>Done at start-up & periodically </li></ul></ul><ul><ul><li>Challenge & Reply </li></ul></ul><ul><ul><ul><li>Remote router sends a one-way hash ~ MD5 </li></ul></ul></ul>
  16. 16. Configuring PPP <ul><li>Step #1: Configure PPP on Router A & Router B : </li></ul><ul><ul><ul><li>Router__# config t </li></ul></ul></ul><ul><ul><ul><li>Router__(config)# int s0 </li></ul></ul></ul><ul><ul><ul><li>Router__(config-if)# encapsulation ppp </li></ul></ul></ul><ul><ul><ul><li>Router__(config-if)#^ Z </li></ul></ul></ul><ul><li>Step #2: Define the username & password on each router: </li></ul><ul><ul><li>RouterA: RouterA(config)# username RouterB password cisco </li></ul></ul><ul><ul><li>RouterB: RouterB(config)# username RouterA password cisco </li></ul></ul><ul><ul><li>NOTE: (1) Username maps to the remote router </li></ul></ul><ul><ul><li> (2) Passwords must match </li></ul></ul><ul><li>Step #3: Choose Authentication type for each router; CHAP/PAP </li></ul><ul><ul><li>Router__(Config)# int s0 </li></ul></ul><ul><ul><li>Router__(config-if)# ppp authentication chap </li></ul></ul><ul><ul><li>Router__(config-if)# ppp authentication pap </li></ul></ul><ul><ul><li>Router__(config-if)#^Z </li></ul></ul>
  17. 17. PPP Example 1
  18. 18. PPP Example 2
  19. 19. PPP Example 3
  20. 20. PPP Example 4
  21. 21. Frame Relay <ul><li>Background </li></ul><ul><ul><li>High-performance WAN encapsulation method </li></ul></ul><ul><ul><li>OSI Physical & data Link layer </li></ul></ul><ul><ul><li>Originally designed for use across ISDN </li></ul></ul><ul><li>Supported Protocols </li></ul><ul><ul><li>IP, DECnet, AppleTalk, Xerox Network Service (XNS), Novell IPX, Banyan Vines, Transparent Bridging, & ISO </li></ul></ul>
  22. 22. Before Frame Relay
  23. 23. After Frame Relay
  24. 24. Frame Relay <ul><li>Purpose </li></ul><ul><ul><li>Provide a communications interface between DTE & DCE equipment </li></ul></ul><ul><ul><li>Connection-oriented Data Link layer communication </li></ul></ul><ul><ul><ul><li>Via virtual circuits </li></ul></ul></ul><ul><ul><ul><li>Provides a complete path from the source to destination before sending the first frame </li></ul></ul></ul>
  25. 25. Frame Relay Terminology
  26. 26. Frame Relay Encapsulation <ul><li>Specified on serial interfaces </li></ul><ul><li>Encapsulation types: </li></ul><ul><ul><li>Cisco (default encapsulation type) </li></ul></ul><ul><ul><li>IETF (used between Cisco & non-Cisco devices) </li></ul></ul><ul><ul><ul><li>RouterA(config)# int s0 </li></ul></ul></ul><ul><ul><ul><li>RouterA(config-if)# encapsulation frame-relay ? </li></ul></ul></ul><ul><ul><ul><li>ietf Use RFC1490 encapsulation </li></ul></ul></ul><ul><ul><ul><li><cr> </li></ul></ul></ul>
  27. 27. Data Link Connection Identifiers (DLCIs) <ul><li>Frame Relay PVCs are identified by DLCIs </li></ul><ul><li>IP end devices are mapped to DLCIs </li></ul><ul><ul><li>Mapped dynamically or mapped by IARP </li></ul></ul><ul><li>Global Significance: </li></ul><ul><ul><li>Advertised to all remote sites as the same PVC </li></ul></ul><ul><li>Local Significance: </li></ul><ul><ul><li>DLCIs do not need to be unique </li></ul></ul><ul><li>Configuration </li></ul><ul><ul><ul><li>RouterA(config-if)# frame-relay interface-dlci ? </li></ul></ul></ul><ul><ul><ul><ul><li><16-1007> Define a DLCI as part of the current </li></ul></ul></ul></ul><ul><ul><ul><li>subinterface </li></ul></ul></ul><ul><ul><ul><li>RouterA(config-if)# frame-relay interface-dlci 16 </li></ul></ul></ul>
  28. 28. DLCI’s are Locally Significant
  29. 29. Local Management Interface (LMI) <ul><li>Background </li></ul><ul><li>Purpose </li></ul><ul><li>LMI Messages </li></ul><ul><ul><li>Keepalives </li></ul></ul><ul><ul><li>Multicasting </li></ul></ul><ul><ul><li>Multicast addressing </li></ul></ul><ul><ul><li>Status of virtual circuits </li></ul></ul>
  30. 30. LMI Types <ul><li>Configuration: </li></ul><ul><ul><ul><li>RouterA(config-if)# frame-relay lmi-type ? </li></ul></ul></ul><ul><ul><ul><li>cisco </li></ul></ul></ul><ul><ul><ul><li>ansi </li></ul></ul></ul><ul><ul><ul><li>q933a </li></ul></ul></ul><ul><ul><li>Beginning with IOS ver 11.2+ the LMI type is auto-sensed </li></ul></ul><ul><ul><li>Default type: cisco </li></ul></ul><ul><li>Virtual circuit status: </li></ul><ul><ul><li>Active </li></ul></ul><ul><ul><li>Inactive </li></ul></ul><ul><ul><li>Deleted </li></ul></ul>
  31. 31. Sub-interfaces <ul><li>Definition </li></ul><ul><ul><li>Multiple virtual circuits on a single serial interface </li></ul></ul><ul><ul><li>Enables the assignment of different network-layer characteristics to each sub-interface </li></ul></ul><ul><ul><ul><li>IP routing on one sub-interface </li></ul></ul></ul><ul><ul><ul><li>IPX routing on another </li></ul></ul></ul><ul><ul><li>Mitigates difficulties associated with: </li></ul></ul><ul><ul><ul><li>Partial meshed Frame Relay networks </li></ul></ul></ul><ul><ul><ul><li>Split Horizon protocols </li></ul></ul></ul>
  32. 32. Partial Meshed Networks
  33. 33. Creating Sub-interfaces <ul><li>Configuration: </li></ul><ul><ul><li>#1: Set the encapsulation on the serial interface </li></ul></ul><ul><ul><li>#2: Define the subinterface </li></ul></ul><ul><ul><ul><li>RouterA(config)# int s0 </li></ul></ul></ul><ul><ul><ul><li>RouterA(config)# encapsulation frame-relay </li></ul></ul></ul><ul><ul><ul><li>RouterA(config)# int s0.? </li></ul></ul></ul><ul><ul><ul><li><0-4294967295> Serial interface number </li></ul></ul></ul><ul><ul><ul><li>RouterA(config)# int s0.16 ? </li></ul></ul></ul><ul><ul><ul><li>multipoint Treat as a multipoint link </li></ul></ul></ul><ul><ul><ul><li>point-to-point Treat as a point-to-point link </li></ul></ul></ul>
  34. 34. Mapping Frame Relay <ul><li>Necessary to IP end devices to communicate </li></ul><ul><ul><li>Addresses must be mapped to the DLCIs </li></ul></ul><ul><ul><li>Methods: </li></ul></ul><ul><ul><ul><li>Frame Relay map command </li></ul></ul></ul><ul><ul><ul><li>Inverse-arp function </li></ul></ul></ul>
  35. 35. Using the map command <ul><ul><li>RouterA(config)# int s0 </li></ul></ul><ul><ul><li>RouterA(config-if)# encap frame </li></ul></ul><ul><ul><li>RouterA(config-if)# int s0.16 point-to-point </li></ul></ul><ul><ul><li>RouterA(config-if)# no inverse-arp </li></ul></ul><ul><ul><li>RouterA(config-if)# ip address 172.16.30.1 255.255.255.0 </li></ul></ul><ul><ul><li>RouterA(config-if)# frame-relay map ip 172.16.30.17 16 ietf broadcast </li></ul></ul><ul><ul><li>RouterA(config-if)# frame-relay map ip 172.16.30.18 17 broadcast </li></ul></ul><ul><ul><li>RouterA(config-if)# frame-relay map ip 172.16.30.19 18 </li></ul></ul>
  36. 36. Using the inverse arp command <ul><ul><li>RouterA(config)# int s0.16 point-to-point </li></ul></ul><ul><ul><li>RouterA(config-if)# encap frame-relay ietf </li></ul></ul><ul><ul><li>RouterA(config-if)# ip address 172.16.30.1 255.255.255.0 </li></ul></ul>
  37. 37. Congestion Control <ul><li>Discard Eligibility (DE) </li></ul><ul><li>Forward-Explicit Congestion Notification (FECN) </li></ul><ul><li>Backward-Explicit Congestion Notification (BECN) </li></ul>
  38. 38. Committed Information Rate (CIR) <ul><li>Definition: Provision allowing customers to purchase amounts of bandwidth lower than what they might need </li></ul><ul><ul><li>Cost savings </li></ul></ul><ul><ul><li>Good for bursty traffic </li></ul></ul><ul><ul><li>Not good for constant amounts of data transmission </li></ul></ul>
  39. 39. Monitoring Frame Relay <ul><ul><ul><li>RouterA> sho frame ? </li></ul></ul></ul><ul><ul><ul><li>ip show frame relay IP statistics </li></ul></ul></ul><ul><ul><ul><li>lmi show frame relay lmi statistics </li></ul></ul></ul><ul><ul><ul><li>map Frame-Relay map table </li></ul></ul></ul><ul><ul><ul><li>pvc show frame relay pvc statistics </li></ul></ul></ul><ul><ul><ul><li>route show frame relay route </li></ul></ul></ul><ul><ul><ul><li>traffic Frame-Relay protocol statistics </li></ul></ul></ul><ul><ul><ul><li>RouterA# sho int s0 </li></ul></ul></ul><ul><ul><ul><li>RouterB# show frame map </li></ul></ul></ul><ul><ul><ul><li>Router# debug frame-relay lmi </li></ul></ul></ul>
  40. 40. Troubleshooting Frame Relay Why can’t RouterA talk to RouterB?
  41. 41. Troubleshooting Frame Relay Why is RIP not sent across the PVC?
  42. 42. Introduction to VPN’s <ul><li>VPNs are used daily to give remote users and disjointed networks connectivity over a public medium like the Internet instead of using more expensive permanent means. </li></ul>
  43. 43. Types of VPN’s <ul><li>REMOTE ACCESS VPNS </li></ul><ul><li>Remote access VPNs allow remote users like telecommuters to securely access the corporate network wherever and whenever they need to. </li></ul><ul><li>SITE-TO-SITE VPNS </li></ul><ul><li>Site-to-site VPNs, or, intranet VPNs, allow a company to connect its remote sites to the corporate backbone securely over a public medium like the Internet instead of requiring more expensive WAN connections like Frame Relay. </li></ul><ul><li>EXTRANET VPNS </li></ul><ul><li>Extranet VPNs allow an organization’s suppliers, partners, and customers to be connected to the corporate network in a limited way for business-to-business (B2B) communications. </li></ul>
  44. 44. Written Labs and Review Questions <ul><ul><li>Open your books and go through all the written labs and the review questions. </li></ul></ul><ul><ul><li>Review the answers in class. </li></ul></ul>

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