Overview
Sometimes network administrators are faced with situations where network documentation is incomplete or inaccurate. Cisco Discovery Protocol (CDP) can be a useful tool in these situations because it can help to build a basic picture of the network. CDP is a media and protocol independent, Cisco proprietary protocol used for neighbor discovery. CDP will only show information about directly connected neighbors but it is nevertheless a powerful tool.

In many cases after a router is initially configured it is difficult or inconvenient for a network administrator to connect directly to the router for configuration changes or other activities. Telnet is a TCP/IP-based application that allows remote connection to the router command-line interface (CLI) for configuration, monitoring, and troubleshooting purposes. It is an essential tool for the network professional.

Students completing this module should be able to:

  • Enable and disable CDP
  • Use the show cdp neighbors command
  • Determine which neighboring devices are connected to which local interfaces
  • Gather network address information about neighboring devices using CDP
  • Establish a Telnet connection
  • Verify a Telnet connection
  • Disconnect from a Telnet session
  • Suspend a Telnet session
  • Perform alternative connectivity tests
  • Troubleshoot remote terminal connections