what does a cdp do?
Cisco Discovery Protocol. Cisco Discovery Protocol (CDP) is a proprietary Data Link Layer protocol developed by Cisco Systems. It is used to share information about other directly connected Cisco equipment, such as the operating system version and IP address.
This chapter describes how the Cisco Discovery Protocol (CDP) works with Simple Network Management Protocol (SNMP) to identify other devices in your network in Cisco IOS Release 12.2. For further details on the commands mentioned in this chapter, refer to the Cisco IOS Configuration Fundamentals Command Reference.