Cisco Systems CCNA 2 manual Implementation, monitoring, and maintenance of CDP

4.1.3 Implementation, monitoring, and maintenance of CDP

CDP implemented by default on all interfaces that support it. The following table lists variations of the CDP command and their functions. These commands should be used in privileged EXEC mode. The table is located in this section of the curriculum.

Although not noted in the curriculum, many of these commands can be executed in user mode. Some of the configuration commands are done in global configuration mode and some require interface configuration mode.

Discuss the cdp enable and cdp run commands. The cdp enable command is an interface configuration command that enables CDP on a particular interface. The cdp run command is a global configuration command that enables CDP on a Cisco device. Students should also be comfortable with the no form of these commands. Relevant TIs from CCNA 2 v2.1.4 are 4.3.3 and 4.3.4.

Demonstrate command usage after the class reviews the table.

Command	Purpose
cdp enable	Enables CDP on an interface
cdp advertise-v2	Enables CDP Version-2 on an interface
clear cdp counters	Resets the traffic counters to zero
show cdp	Displays the interval between transmissions of
	CDP advertisements, the number of seconds the
	CDP advertisement is valid for a given port, and
	the version of the advertisement
show cdp entry entry-name	Displays information about a specific neighbor,
[protocol version]	which can be limited to protocol or version
	information
show cdp interface [type	Displays information about interfaces on which
number]	CDP is enabled
show cdp neighbors [type	Displays the type of device that has been
number] [detail]	discovered, the name of the device, the number
	and type of the local interface or port, the number
	of seconds the CDP advertisement is valid for the
	port, the device type, the device product number,
	and the port ID
	Displays information on the native VAN ID, the
	duplex mode, and the VTP domain name
	associated with neighbor devices when the
	detail keyword is used

4.1.4 Creating a network map of the environment

CDP uses advertisements to collect information about its neighbors. Its limitation is that it only collects information from directly-connected devices. The telnet command can be used in conjunction with cdp commands to create a network map. To do this, a network administrator can console into one router and use the telnet command to move from router to router.

42 - 238 CCNA 2: Routers and Routing Basics v3.1 Instructor Guide – Module 4 Copyright ♥ 2004, Cisco Systems, Inc.