Cisco Discovery Protocol (CDP)

Cisco Discovery Protocol, or CDP, is a proprietary Cisco Layer 2 network protocol used to discover directly connected network devices. Supported devices such as switches, routers and IP phones periodically exchange information with neighbouring devices. This information can include the device name, IP address, hardware model, connected port and operating system version. Network administrators can use CDP data to understand network topology, verify connections and troubleshoot network configuration issues more efficiently. As CDP operates at the data link layer of the OSI model, devices do not require an IP connection to exchange this information. For security purposes, CDP can be disabled on interfaces where automatic device information exchange is not required.