The Cisco Discovery Protocol (CDP) is a protocol that Cisco devices use to learn and share information about each other. Cisco devices, such as routers and switches, can discover neighboring Cisco devices through CDP.
- By default, CDP is enabled on all interfaces.
- CDP only shares information with directly connected (neighboring) devices.
- CDP works when there is a valid Data Link layer connection.
- CDP works regardless of the Network layer and other protocols used. It can discover information on LANs, Frame Relay, and other network architectures.
Use the following commands to customize and view CDP information.
The following commands turns on CDP for the router and configures it to send CDP packets every 90 seconds.
Router(config)#cdp run Router(config)#cdp timer 90
The following commands turns off CDP on the router’s first Ethernet interface.
Router(config)#int eth 0 Router(config-if)#no cdp enable