CDP is a network discovery tool that assists network engineer or administrator in identifying neighboring Cisco devices.
CDP is a layer 2 protocol.
It is a Cisco proprietary protocol and can only be run on Cisco devices.
By default, CDP is enabled on all Cisco routers and switches.
CDP packets are sent to a multicast address every 60 seconds.
CDP runs on all LAN and WAN media that supports SNAP protocol.
Below is the command to enable CDP globally.
Switch(config)# cdp run
Command to disable CDP globally.
Switch(config)#no cdp run
Command to enable CDP on a interface
Command to disable CDP on a interface
Switch(config-if)#no cdp enable
Display CDP information
Switch#show cdp neighbors
Display CDP information for a interface
Switch#show cdp interface fa0/1
Clear CDP counters
Switch# clear cdp counters
Deleting CDP neighbors table
Switch# clear cdp table