1. Copyright 2003 www.ciscopress.com Introduction to Computer Networking Learning About Other Devices

2. Copyright 2003 www.ciscopress.com Objectives Cisco Discovery Protocol Getting information about remote devices using CDP TELNET Packet Internet Groper (Ping) Trace

3. Copyright 2003 www.ciscopress.com Getting Information about Remote Devices Cisco Discovery Protocol is used for viewing other directly connected devices Only works with Cisco Hardware Does not need IP addressing to be setup Independent of layer 3 OSI

4. Copyright 2003 www.ciscopress.com Using the Cisco Discovery Protocol (CDP) Showing CDP neighbor entries A CDP configuration example Showing CDP entries for a device Showing CDP neighbors

5. Copyright 2003 www.ciscopress.com Cisco Discovery Protocol (CDP) CDP is media and protocol independent, and runs on all Cisco equipment over the Subnetwork Access Protocol (SNAP).

6. Copyright 2003 www.ciscopress.com Showing CDP Neighbor Entries

7. Copyright 2003 www.ciscopress.com CDP Configuration Example

8. Copyright 2003 www.ciscopress.com The show cdp neighbors Command

9. Copyright 2003 www.ciscopress.com Implementation, Monitoring, and Maintenance of CDP The following commands are used to implement, monitor and maintain CDP information: cdp run cdp enable clear cdp counters show cdp show cdp entry entry-name [protocol | version] show cdp interface [type number] show cdp neighbors [type number] [detail]

10. Copyright 2003 www.ciscopress.com Creating a Network Map The show cdp neighbors [type number] [detail] command can be used to obtain the following: Device ID — Address Port ID — Capabilities Version — Platform IP network prefix VTP management domain name (CDPv2 only) Native VLAN (CDPv2 only) Full/Half duplex (CDPv2)

11. Copyright 2003 www.ciscopress.com Disabling CDP To disable CDP on a specific interface after it has been enabled, use the no cdp enable command in interface configuration mode.

12. Copyright 2003 www.ciscopress.com Troubleshooting CDP show cdp clear cdp table show cdp traffic show debugging debug cdp cdp timers cdp holdtime debug cdp adjacency debug cdp events debug cdp ip debug cdp packets

13. Copyright 2003 www.ciscopress.com Telnet

14. Copyright 2003 www.ciscopress.com Disconnecting and Suspending Telnet Sessions

15. Copyright 2003 www.ciscopress.com Establishing Telnet Connections A host name table or access to DNS for Telnet must be present for a name to work. Otherwise, the IP address of the host must be entered. Denver>connect paris Denver>paris Denver>131.108.100.152 Denver>telnet paris Telnet can be used to perform a test to determine whether access can be obtained from a remote router.

16. Copyright 2003 www.ciscopress.com Advanced Telnet Multiple Telnet sessions can be used and suspended by using the Ctrl+Shift+6 and x sequence.

17. Copyright 2003 www.ciscopress.com The ping Command

18. Copyright 2003 www.ciscopress.com The trace Command

19. Copyright 2003 www.ciscopress.com Conclusion CDP is used to gather data about Cisco devices Ping can discover if a host is online Traceroute can check the path to another host TELNET is used for remote logins