Learning All About Router

CDP allows devices to share basic configuration information without even configuring any protocol specific information. CDP is enabled by default on all interfaces.
CDP is a Datalink Protocol occuring at Layer 2 of the OSI model. This is important to understand because CDP is not routable. It can only traverse to directly connected devices.
CDP allows you to view information such Operating System Version, Protocol Information, and much more. This can be very handy for troubleshooting a variety of problems.
CDP ConfigurationBy default it is enabled on the router and all interfaces. The commands are simple:

Global Configuration Commands:
no cdp run turn off CDP for the entire router cdp run (default) turn it on for the entire router cdp timer 120 would change CDP to advertise every 120 seconds
Interface Configuration Commands:
cdp enable (default) turn it on for the interface no cdp enable turn it off for interface
Show Commands:
show cdp interface view interface settings,
show cdp neighbor view directly connected neighbors
show cdp neighbor detail view detailed information about neighbors show cdp general information Copyright (c) 2001 Boson Software, Inc. All Rights Reserved.