Discovering and Connecting to Neighbors | Cisco Systems CCNA 2

•Troubleshoot remote terminal connections

4.1Discovering and Connecting to Neighbors

Essential Labs:	4.1.4 and 4.1.6
Optional Labs:	None
Core TIs:	All
Optional TIs:	none

Course-Level Claim: Students can use embedded data-link layer functionality to perform network neighbor discovery and analysis from the router console.

Hands-on skills: none

4.1.1 Introduction to CDP

CDP is a Cisco proprietary protocol that is used for Layer 2 troubleshooting and network documentation. CDP is used to acquire protocol and platform information from neighboring devices. It is enabled by default on Cisco devices and requires all media that is used to be Subnetwork Address Protocol (SNAP) enabled. Most media is SNAP enabled.

During the boot-up process, each Cisco device sends CDP advertisements to a multicast address to collect information from its neighbors. These advertisements are periodically repeated so that updated information can be gathered. CDP advertisements are also used by the receiving devices to learn about the sender. CDP information is dynamic. It is constantly updated through periodic advertisements. Reporting devices provide a Time-to-Live (TTL) value for the data.

CDP operates at Layer 2 and is upper layer independent. Review Figure 1 with students. CDP allows each Cisco device to collect information from its neighbors regardless of the Layer 3 protocols the devices are configured to use. Discuss the following characteristics of CDP:

•CDP runs on all Cisco devices such as routers, switches, and bridges.

•CDP is Cisco proprietary.

•CDP is upper-layer independent.

•CDP information is exchanged only by directly-connected neighbors.

Students may not be familiar with multicasting. A brief explanation may be required at this point. The following link provides information on Cisco IP multicast implementation.

http://www.cisco.com/warp/public/732/Tech/multicast

40 - 238 CCNA 2: Routers and Routing Basics v3.1 Instructor Guide – Module 4

Copyright ♥ 2004, Cisco Systems, Inc.

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Cisco Systems CCNA 2 manual Discovering and Connecting to Neighbors, Introduction to CDP, Essential Labs Optional Labs

Contents

Page Student-Centered, Instructor-Facilitated Welcome Hands-On, Skills-Based One Size Does Not Fit All Guide Overview Global Community Target Audience II. Course OverviewPrerequisites Course Description Certification Alignment Lab Requirements Course Overview Copyright 2004, Cisco Systems, Inc Nomenclature III. Teaching Guide for Each TI Module Target indicator TILearning objective LO Lesson Module 1 Caution Module 1 WANs and RoutersOverview Introduction to routers in a WAN WANsIntroduction to WANs ROM Router LANs and WANs Academy approach to hands-on labs Role of Routers in a WAN Routers Router physical characteristics Console Port Connections Router external connectionsManagement port connections Connecting WAN interfaces Connecting Router LAN interfaces Module 1 Summary Module 2 Caution Module 2 Introduction to Routers Purpose of Cisco IOS software Operating Cisco IOS SoftwareRouter user interface Router user interface modes Operation of Cisco IOS software Cisco IOS software features Initial router bootup Router LED indicatorsStarting a Router Initial startup of Cisco routers Keyboard help in the router CLI Router loginEstablish a console session Router command history Enhanced editing commands Show version command Troubleshooting command line errors Module 2 Summary Module 3 Caution Module 3 Configuring a Router Copyright 2004, Cisco Systems, Inc CLI command modes Configure a Router Configuring router passwords Configuring a router name Examining the show commands Making configuration changes Configuring a serial interface Router#copy running-config startup-config Configuring an Ethernet interface Importance of configuration standards Finishing the Configuration Interface descriptions Configuring an interface description Host name resolutions Login bannersConfiguring message-of-the-day Motd Backing up configuration files Configuring host tablesConfiguration backup and documentation Copyright 2004, Cisco Systems, Inc Module 3 Summary Module 4 Caution Use the show cdp neighbors commandModule 4 Learning about Other Devices Essential Labs Optional Labs Discovering and Connecting to NeighborsIntroduction to CDP TLV Information obtained with CDP Creating a network map of the environment Implementation, monitoring, and maintenance of CDP Disabling CDP Troubleshooting CDP Command Purpose Telnet Getting Information about Remote DevicesEstablishing and verifying a Telnet connection Router131.108.100.152 Advanced Telnet operation Disconnecting and suspending Telnet sessionsCtrl -Shift -6 then Resume StanlyLab#show sessions Alternative connectivity tests LAB-D#ping lab-c LAB-B#ping lab-cLAB-A#trace lab-e LAB-A#trace lab-d LAB-C#show ip route Troubleshooting IP addressing issues Module 4 Summary Module 5 Managing Cisco IOS Software Stages of the router power-on boot sequence Router Boot Sequence and VerificationHow a Cisco device locates and loads the Cisco IOS Essential Labs Optional Labs None Core TIs All Optional TIs Troubleshooting IOS boot failure Using the boot system commandConfiguration register Additional Resources Managing the Cisco File System IOS naming convention IOS file system overview Managing configuration files using copy and paste Managing configuration files using TftpEnter copy tftp running-config Select Transfer Capture Text Show running-config Managing IOS images using XModem Managing IOS images using Tftp File system verification Environment variables Discuss the following alternatives with the students Module 5 Summary Module 6 Caution Module 6 Routing and Routing Protocols Static route operation Introduction to Static RoutingIntroduction to routing Rt1config#ip route 192.168.2.0 255.255.255.0 192.168.1.2 Rt1config#ip route 192.168.2.0 255.255.255.0Rt1config#ip route 192.168.2.0 255.255.255.0 s0 Rt1#config terminal Configuring static routes Verifying static route configuration Configuring default route forwarding Show ip route output Rt1#show ip route Troubleshooting static route configuration Rt1#ping Rt1#show interfaces s0 Autonomous systems Dynamic Routing OverviewIntroduction to routing protocols Identifying the classes of routing protocols Distance vector routing protocol featuresPurpose of a routing protocol and autonomous systems Routing Protocols Overview Link-state routing protocol features Routing protocols Routing configurationPath determination IGP versus EGP Module 6 Summary Module 7 Caution Module 7 Distance Vector Routing ProtocolsOverview Distance Vector Routing Distance vector routing updatesDistance vector routing loop issues Problem Routing Loops Eliminating routing loops through split horizon Defining a maximum count Routing Update Route poisoning Avoiding routing loops with triggered updates RIP Preventing routing loops with holddown timers RIP routing process Configuring RIP Common RIP configuration issues Using the ip classless command LAB-A#debug ip rip Verifying RIP configurationTroubleshooting RIP update issues Load Balancing with RIP Preventing routing updates through an interface Load balancing across multiple paths IgrpIntegrating static routes with RIP Essential Labs Optional Labs Core TIs Igrp metrics Igrp features Igrp routes Igrp stability features Migrating from RIP to Igrp Configuring IgrpVerifying Igrp Configuration Troubleshooting Igrp Module 7 Summary Ip classless command Copyright 2004, Cisco Systems, Inc Module 8 Caution Module 8 TCP/IP Suite Error and Control Messages Error reporting and error correction Overview of TCP/IP Error MessageIcmp Icmp message delivery Detecting excessively long routes Using ping to test destination reachabilityUnreachable networks Destination unreachable message Miscellaneous error reportingEcho messages Icmp redirect/change requests TCP/IP Suite Control MessagesIntroduction to control messages Information requests and reply message formats Clock synchronization and transit time estimationAddress mask requests Router discovery message Congestion and flow control messages Router solicitation message Module 8 Summary Module 9 Caution Module 9 Basic Router Troubleshooting Determining the gateway of last resort Show ip route commandExamining the Routing Table Determining L2 and L3 addresses Determining route administrative distanceDetermining route source and destination Determining the route next hop Determining the last routing updateDetermining the route metric Introduction to network testing Network TestingUsing a structured approach to troubleshooting Observing multiple paths to destination Layer 1 troubleshooting using indicators Testing by OSI layersLayer 3 troubleshooting using ping Layer 7 troubleshooting using Telnet Troubleshooting Layer 1 using show interfaces Troubleshooting Router Issues OverviewTroubleshooting Layer 2 using the show interfaces Troubleshooting using show cdp Troubleshooting using show controllers Troubleshooting using tracerouteTroubleshooting routing issues Introduction to debug Show cdp Traceroute Show controllers serial Debug Module 9 Summary Module 10 Caution Module 10 Intermediate TCP/IP Synchronization or three-way handshake TCP OperationTCP operation Windowing and window size Denial of service attacks UDP operation Sequencing numbersPositive acknowledgements Multiple conversations between hosts Overview of Transport Layer Ports Port numbering and well known port numbers Ports for servicesPorts for clients Comparison of MAC addresses, IP addresses, and port numbers Example of multiple sessions between hosts Module 10 Summary Access Control List Fundamentals Module 11 Access Control List ACLs How ACLs work Introduction to ACLs Rt1config#access-list 1 permit ? Rt1config#access-list ?Rt1config#access-list 1 permit 192.168.0.1 ? Creating ACLs C.D Wildcard bits Log Verifying ACLs Function of a wildcard mask Standard ACLs Access Control Lists ACLs Extended ACLs Rt1config#access-list 101 ?Rt1config#access-list 101 permit ? Named ACLs Firewalls Placing ACLs Restricting virtual terminal access Module 11 Summary Overview and Objectives IV. Case Study Scenario and Phase 1 Project Description Network Diagram IP Addressing Phase 2 IP Addressing Boaz Center Phase 3 Basic Router and Workstation Configuration Instructor approval Date Ping from Router Boaz to Workstation Phase 4 Access Control Lists Configuration management documentation Boaz Phase 5 Documenting the NetworkEva Security management documentation Boaz Eva Technical Documentation Case Study DeliverablesGeneral Documentation Copyright 2004, Cisco Systems, Inc Class Range Phase 1 Project DescriptionCase Study Instructor Notes Optional Case Study Instructor Sample Outputs Phase 5 Documenting the Network Sample outputs Boaz Boaz#show ip interface brief Boaz#show startup-config Using 1090 out of 32762 bytes Boaz#show ip interface Security Management documentation Boaz Copyright 2004, Cisco Systems, Inc Configuration Management documentation Phase 5 Documenting the Network Sample outputs Centre Centre#show version Copyright 2004, Cisco Systems, Inc Centre#show ip interface Security Management documentation Centre Centre#show ip access-lists Configuration Management documentation Eva Phase 5 Documenting the Network Sample outputs Eva Eva#show hosts Eva#show startup-config Using 1156 out of 32762 bytes Eva#show ip interface Security Management documentation Eva Copyright 2004, Cisco Systems, Inc Appendices Appendix a Cisco Online Tools and Utilities Output Interpreter Error Message Decoder Software Bug Toolkit IP Subnet Calculator Password Recovery Procedures TAC Case Collection Software Advisor Feature Navigator TAC Advanced Search Best Practices What is meant by best practices? Nets Standards Nets Literacy, math, and science standards Web Links Timss Report Participating Countries Timss report Learner Model Academy Student Student-centered learning Multiple Intelligences Multiple intelligences Web Links Inquiry Based Learning Inquiry-based learning Special Needs Special needs Web Links Learning Disabilities Learning disabilities Strategies for Teaching Students with Learning Disabilities Ccna labs Lab-Centric Instruction PPP Isdn Ccnp Labs Ccnp labs Web Links Netlab Web Links Simulations Simulations Sponsored Curriculum Labs Sponsored curriculum labs Sponsored Curriculum Labs Fundamentals of Voice and Data Cabling IT Essentials PC Hardware and Software IT EssentialsIT Essentials Network Operating Systems Fundamentals of Web Design Fundamentals of UnixFundamentals of Java Programming Http//cisco.netacad.net/cnacs/prot-doc/newcourses.html PIX Firewall PhotoZoom Emerging technologies Wireless solutions Steps in the Problem-Solving Model Troubleshooting Teaching Methods Web Resources Challenges and projects Project-based Instruction Copyright 2004, Cisco Systems, Inc Design activities Dartmouth Problem-Solving Cycle Web Links Brainstorming Cluster Diagram Gifted Education a Resource Guide for Teachers Case Studies Case studies Case Study Teaching in Science a Bibliography Cisco.com Web research Instructor-led classrooms Instructional Strategies Copyright 2004, Cisco Systems, Inc Self-paced instruction Small groups Cooperative/collaborative workPairs or partners Competitive teams TeamsLarge groups Whole class Student-led discussions Demonstrations Presentations Jigsaw Puzzle Jigsaws Ask the Right Questions Ask the right questions Copyright 2004, Cisco Systems, Inc PMI 6 PMI Graphic organizers Problem-Solving Matrix Flowchart Extended Star Topology in a Multi-Building Campus Digital Signal Data Encapsulation Local Area Networks and Devices Copyright 2004, Cisco Systems, Inc RFI EMI Setting goals Kinesthetic Activities Kinesthetic activities Web Links Review strategies Assessment Strategies Journals and reflection Copyright 2004, Cisco Systems, Inc Web Links Grading Rubric Sample Rubrics Rubistar http//rubistar.4teachers.org Guidelines for Portfolio Assessment in Teaching English Portfolio Oral Exams Oral exams Copyright 2004, Cisco Systems, Inc Lab Exams Lab exams Web Links Six Lenses Six lenses Copyright 2004, Cisco Systems, Inc