What is the Cisco Discovery Protocol (CDP) ?

The Cisco Discovery Protocol (CDP) is a proprietary layer 2 network protocol developed by Cisco Systems that runs on most Cisco equipment and is used to share information about other directly connected Cisco equipment such as the operating system version and IP address.


(config)# cdp run
(config)# no cdp run


To disable,

(config-if)# no cdp enable

To enable,

(config-if)# cdp enable

Additional Commands

# show cdp
# show cdp neighbor detail
# show cdp neighbor
# show cdp interface
(config)# cdp timer 45
(config)# cdp holdtime 60

Tags: CCIE R+S

About the Author


R Donato

Rick Donato is the Founder and Chief Editor of He currently works as a Principal Network Security Engineer and has a keen interest in automation and the cloud.

You can find Rick on Twitter @f3lix001