Complex sentence: The Cisco Discovery Protocol (CDP) is a proprietary Data Link Layer network protocol developed by Cisco Systems that is implemented in most Cisco networking equipment and is used to share information about other directly connected Cisco equipment, such as the operating system version and IP address.
Split into simpler sentences: The Cisco Discovery Protocol (CDP) is a proprietary Data Link Layer network protocol developed by Cisco Systems that is implemented in most Cisco networking equipment. It is used to share information about other directly connected Cisco equipment, such as the operating system version and IP address.